CO and O2In e ac ion wi h Kinked P Su aces
Fe nando Ga cía-Ma ínez, Elia Tu co, F ede ik Schille , and J. En ique O ega*
Ci e This: ACS Ca al. 2024, 14, 6319−6327
Read Online
ACCESS Me ics & Mo e A icle Recommenda ions *
sı Suppo ing In o ma ion
ABSTRACT: We in es iga e he chemical in e ac ion o ca bon
monoxide (CO) and oxygen (O2) wi h kink a oms on s eps o
pla inum c ys al su aces using a specially designed P cu ed
sample. We aim a desc ibing he undamen al s ages o he CO
oxida ion eac ion, i.e., CO-co e ed/poisoned s age and O-
co e ed/ac i e s age, a he poo ly known kinked P ace s by
p obing CO up ake/sa u a ion and O2sa u a ion, espec i ely.
Based on he sys ema ic analysis ha he cu ed su ace allows, and
using high- esolu ion X- ay pho oemission, a di e si y o e ace
and s ep/kink species a e s aigh o wa dly iden i ied and
accu a ely quan i ied, de ining a smoo h s uc u al and chemical
a ia ion ac oss di e en c ys al planes. In he CO-sa u a ed case,
we obse e a p e e en ial adso p ion a s ep edges, whe e he CO
co e age eaches a CO molecule pe s ep P a om, signi ican ly highe han hei close-packed analogous s eps wi h s aigh e ace
e mina ion. Fo he O-sa u a ed su ace, a signi ican ly highe O co e age is obse ed in kinked planes compa ed o he P (111)
su ace. While he s ong adso p ion o CO a he kinked edges poin s owa d a highe igni ion empe a u e o he CO oxida ion a
kinks as compa ed o e aces, he la ge O co e age a s eps may lead o an inc eased eac i i y o kinked su aces du ing he ac i e
s age o he CO oxida ion.
KEYWORDS: CO adso p ion, O2adso p ion, pla inum, cu ed c ys al, kinked su ace, X- ay pho oemission spec oscopy
■INTRODUCTION
The s udy o he ca bon monoxide (CO) oxida ion s ands as
undamen al in comp ehending su ace ca aly ic eac ions,
holding a p ominen place in su ace science esea ch.
1−4
Howe e , mos in es iga ions o da e ha e occu ed unde
con olled condi ions, ei he using single c ys als o in ul ahigh
acuum (UHV) en i onmen s, de ached om he eal
condi ions o indus ial applica ions. Consequen ly, ex ending
su ace science indings o eal ca aly ic sys ems, ope a ing a
a mosphe ic p essu es (p essu e gap), and in ol ing powde /
nanopa icle ca alys s (ma e ials gap), may lead o inaccu acies.
5
New expe imen al app oaches a e needed o allow he mos
powe ul echniques o b idge bo h he p essu e gap, such as
nea ambien p essu e x- ay pho oemission (NAP-XPS), and he
ma e ials gap h ough no el sample designs. In he la e case, i
is impo an o ealize ha me allic nanopa icles possess
mul iple ace s, making i di icul o ack hei speci ic ac i i y
and in e ac ions du ing he chemical eac ion.
6
The e o e,
con en ional single-c ys al su aces o e limi ed in o ma ion as
hey ep esen only one plane, ailing o mi o he complex,
mul i ace ed s uc u e o ac ual ca alys s.
7
One po en ial
app oach o b idge he s uc u al gap in ol es he u iliza ion
o cylind ical sec o s o single c ys als. Thei cu ed su aces
allow o a smoo h ansi ion in he c ys al o ien a ion, enabling
a sys ema ic compa ison o a ious ace s unde iden ical
eac ion condi ions. Mo eo e , wi h a p ope selec ion o he
c ys al sec o , a cu ed su ace also o e s a sophis ica ed bu
consis en means o analyzing icinal su aces, hence he e ec o
unde coo dina ed, s ep a oms in su ace-ca alyzed eac-
ions.
8−11
The combined use o cu ed su aces wi h (NAP-)XPS has
success ully demons a ed i s po en ial o s aigh o wa dly
assess he ole o s eps in he CO oxida ion on Pd, P , and Rh
icinals
12−14
o Ag-oxida ion,
15
among o he ma e s.
16
The
cu ed geome y allowed he iden i ica ion o su ace species a
di e en eac ion s ages and an accu a e de e mina ion o he
igni ion empe a u e ac oss di e en ace s. Su p isingly, species
and igni ion empe a u es we e ound he same a A- ype
({100}-o ien ed mic o ace s) and B- ype ({111} mic o ace s)
s epped P (111) su aces,
14
by con as o he expec ed A/B
asymme ies obse ed in Pd and Rh.
12,13
Ye he ques ion a ises
whe he such homogeneous and symme ic beha io in P
occu s a beyond he (111) plane o ea u es di e en s ep
geome ies in he icini y o he P (111) su ace, such as he
mo e open kinked s eps (Figu e 1a). Thei complexi y is
Recei ed: Janua y 19, 2024
Re ised: Ma ch 20, 2024
Accep ed: Ma ch 20, 2024
Published: Ap il 10, 2024
Resea ch A iclepubs.acs.o g/acsca alysis
© 2024 The Au ho s. Published by
Ame ican Chemical Socie y 6319
h ps://doi.o g/10.1021/acsca al.4c00435
ACS Ca al. 2024, 14, 6319−6327
This a icle is licensed unde CC-BY 4.0
Downloaded ia UNIV DEL PAIS VASCO on May 17, 2024 a 12:01:54 (UTC).
See h ps://pubs.acs.o g/sha ingguidelines o op ions on how o legi ima ely sha e published a icles.
p obably he eason why hey ha e been poo ly in es iga ed wi h
XPS in he CO oxida ion con ex , e en unde UHV
condi ions.
17,18
No e ha he UHV-XPS s udy is a e y ele an
s ep
8,10,11
since i allows o de e mine co e-le el shi s o he
a ie y o chemical species ha a ise in he p esence o s eps,
he eby p o iding accu a e e e ence spec a o NAP-XPS,
which gene ally exhibi s lowe esolu ion and poo e s a is ics.
CO and O2adso p ion s udies using UHV-XPS a e abundan
o P (111) and i s A/B icinal su aces; hence, he esul ing
CO/P and O/P in e aces and adso p ion si es a e well
es ablished. They a e ske ched in Figu e 1b,c. Exposing he
(111) plane o CO a oom empe a u e (300 K) will ypically
gi e ise o a c(4 ×2)-4CO pa e n wi h 0.5 monolaye s (ML,
one adso bed molecule pe subs a e su ace a om),
19
while a
mo e dense o e laye packing (0.68 ML) can be achie ed when
exposing he su ace o CO in NAP condi ions.
20−22
In P (111)
close-packed icinals, CO is known o adso b on op si es a he
uppe edge (ST) o B- ype s eps.
23−25
In A- ype s eps, in
addi ion o he SToccupa ion, a small amoun o CO adso bs a
b idge posi ions (SB).
26−29
On he o he hand, exposing he
P (111) su ace o O2abo e 77 K leads o he immedia e
molecula dissocia ion, wi h O a oms a anged in a p(2 ×2)
laye .
30−32
This s uc u e co esponds o 0.25 ML co e age wi h
O a oms occupying h ee- old cc hollow si es.
33−35
Highe O
co e ages lead o he o ma ion o one-dimensional (1D)
oxygen s ipes, e en ually condensing in o a s uc u e whe e
ows o P su ace a oms appea linked o ou oxygen a oms
each (“4O” P su ace oxide).
36−39
A P -s epped su aces wi h
(111) e aces and A/B- ype s eps, he dissocia i e O2
adso p ion and he subsequen chemiso p ion a e a o ed a
s eps o e e aces,
40−44
esul ing in o oxygen a oms ancho ed
o b idge si es a A- ype s eps, and hollow cc posi ions close o
he edge a B- ype s eps.
41,45−47
Finally, a e he sa u a ion o
he oxygen chemiso p ion, 1D “4O”-like chains along he s ep
edges we e also obse ed o P icinal su aces wi h A/B
s eps.
40,48,49
Adso p ion expe imen s on icinal P (111) su aces
wi h kinked s eps a e much sca ce. Ea ly wo ks on he CO
adso p ion on kinked P su aces epo ed STas he p e e en ial
si e, al hough a small amoun o SBmay also be p esen .
17
Fo
O2, while i is clea ha O binds s onge on he kinks as
compa ed o e aces, he na u e o he adso bed species emains
unknown.
50−52
An XPS s udy by Held e al. in P (531)
18
epo ed h ee di e en species a e annealing he su ace in
≈10−7mba O2, i.e., one chemiso bed s a e and wo ypes o
oxide clus e s.
Using a P cu ed c ys al wi h a special design and UHV-XPS,
he e we in es iga e a wide ange o P icinal su aces wi h
kinked s eps du ing CO and O sa u a ion a 300 K. They
ep esen he wo undamen al s ages o he CO oxida ion
eac ion, i.e., he CO-poisoned and he O-ac i e su aces. The
sample is a cylind ical sec o o a P c ys al, wi h cylinde axis
pa allel o he [112] di ec ion (see Figu e 1 and Me hods in he
Suppo ing In o ma ion) and he (645) di ec ion a he cen e
o he cu ed su ace [c-P (645) sample]. The e e ence (111)
plane is loca ed close o one edge, allowing P icinal su aces o
be spanned wi h kinked s eps up o a α= 28° icinal (o il )
angle wi h espec o he (111) plane. The la ge icinal angle
ange allows us o each all icinal su aces om he (111)
beyond he densely kinked (312) su ace (2-a om-wide
e aces) a he opposi e sample edge. Th ough up ake and
sa u a ion expe imen s on his sample, we iden i y a a ie y o
CO and O species, which can also be quan i ied and discussed in
model adso ba e s uc u es, hanks o he sys ema ic app oach
ha only he cu ed geome y allows.
■EXPERIMENTAL METHODS
Sample Cleaning and Cha ac e iza ion. The c-P (645)
sample, ea u ing he (645) plane a i s apex, is desc ibed in
Figu e 1. The sample is cleaned wi h A +spu e ing cycles a 1
kV, O2annealing (1 ×10−7mba , 800 K), and inal lashes (950
K) un il no con aminan s a e seen in he XPS spec um. Low-
ene gy elec on di ac ion (LEED) was employed o p obe he
su ace s uc u e o he cu ed su ace. Di ac ion pa e ns and
he P 4 XPS egion o he clean c-P (645) c ys al a e shown in
Figu e S1.
X- ay Pho oemission Expe imen s and Peak Fi ing.
XPS was ca ied ou a he Supe ESCA beamline o Ele a
synch o on in T ies e (I aly)
53
in no mal emission geome y.
The beam inge p in is ≈20 μm in he e ical di ec ion, i.e.,
along he pe pendicula di ec ion o he s eps and he cu a u e
o he c ys al, allowing p obe o icinal su aces wi hin an
accu acy below 0.1°. We obse ed beam damage e ec s du ing a
long measu emen (>30 min) in P (111) a e CO sa u a ion, as
a small ac ion o CO adso bed a TBdissocia ed owa d “C”.
The e o e, we educed ou measu emen ime a he posi ions o
he α-scan (<10 min) o minimize beam damage e ec s. The
peak i ing was pe o med using he lm i package o Py hon.
54
Figu e 1. c-P (645) sample. (a) Side- iew desc ip ion o he sample, which is a cylind ical P c ys al sec o , wi h cylinde axis pa allel o he [112]
di ec ion. The a omic models ske ch he cha ac e is ic (645) and (312) planes, ea u ing kinked s eps and (111) e aces o 5 and 2-a om- owwid h,
espec i ely. In (b,c), we ske ch ele an adso p ion geome ies o CO and O a (111) e aces and s epped kinks. Fo CO, TTand TBs and o
molecules adso bed in Te ace-Top and B idge posi ions, while ST6, ST8, and SB, espec i ely, e e o he CO adso bed on S ep-Top si es in he i s
(six- old-coo dina ed P ), he second (eigh - old-coo dina ed P ) ow, and a S ep-B idge posi ions. Fo oxygen, O cc and OKco espond o O
adso bed a h ee- old cc hollow and b idge kink-si es, espec i ely, while “4O” e e s o oxygen a anged in a local P chain s uc u e wi h P O4mo i s
(see he main ex ).
ACS Ca alysis pubs.acs.o g/acsca alysis Resea ch A icle
h ps://doi.o g/10.1021/acsca al.4c00435
ACS Ca al. 2024, 14, 6319−6327
6320
Doniach−Sunjic line shapes
55
con olu ed wi h a Gaussian we e
conside ed o he asymme ic peaks (adso bed CO in he C 1s,
g aphi ic C, and a omic O), while Voig p o iles we e used o
symme ic peaks (adso bed CO in he O 1s, “4O”-like s ipes),
oge he wi h a Shi ley- ype backg ound.
56
Small peaks asc ibed
o ib a ional exci a ions o CO molecules
57−59
could be
dis inguished in he high- esolu ion C 1s spec a o Figu e 3;
hence, hey we e included in he i ing p ocedu e. F om he i
o he (111) su ace, he sa elli es we e ixed a 220 meV owa d
highe binding ene gy o he main con ibu ion, and he
in ensi y a io de i ed was 11.5% and 10% o TTand TBsi es,
espec i ely. The o he pa ame e s we e cons ain o hose o
he majo peak, and hei a ea was added o ha o he main
ea u e o quan i ica ion. The in ensi y a io o he TTsa elli e
was applied o he ST6 and ST8 sa elli es. In he case o he
up ake and deso p ion expe imen s, spec a we e acqui ed
conside ably as e han he high- esolu ion spec a. Fo his
eason, ST6 + ST8 we e no esol ed; hence, a single peak STwas
employed. Sa elli es we e nei he esol ed.
Co e age Calib a ion. The co e age o high- esolu ion
spec a o Figu e 3 was calib a ed using he c(4 ×2) pa e n
obse ed by LEED as a e e ence. As desc ibed in e .,
25,29,60
a
ac o ex ac ed om he (111) needs o be applied o CO
adso bed in b idge si es o p ope ly accoun o hei co e age.
Such a ac o was applied o he in ensi y o TBwhen con e ing
peak a ea o co e age. In up ake expe imen s, co e age was
calcula ed by assuming sa u a ion o TTsi es in he (111) plane
measu emen . In he case o he deso p ion expe imen s, since
he pho on ene gy is di e en , we also assumed CO sa u a ion a
he beginning o he deso p ion amp a he (111) su ace. O 1s
in ensi ies we e calib a ed using he p(2 ×2)-O supe s uc u e
obse ed in he (111) plane by LEED.
■RESULTS
CO Up ake. In o de o iden i y p e e en ial adso p ion si es,
sepa a e CO up ake expe imen s we e pe o med a he (111),
(645), and (312) su aces on he c-P (645) sample. These
su aces we e exposed o 1 ×10−9mba o CO a 300 K while
con inuously eco ding he C 1s pho oemission peak, he la e
shown as colo plo s in Figu e 2a−c. In Figu es 2d− , we display
indi idual spec a a 0.2 L and close o sa u a ion, oge he wi h
hei espec i e peak i analyses, om which peak in ensi ies o
each co e-le el line a e de e mined. The la e and he o al C 1s
in ensi y a e ep esen ed in Figu e 2g−i o he h ee di e en
su aces. As shown in Figu e 2d, in he (111) su ace, and sho ly
a e he CO exposu e begins, a peak appea s a 286.7 eV, which
belongs o CO ancho ed a op P (111) a oms (Te ace-Top,
TT).
60
La e , and a a slowe pace, ano he ea u e de elops a
286.0 eV, which co esponds o CO adso bed a b idge si es
(Te ace-B idge, TB).
31,60,61
The e olu ion o hese wo CO
species is shown in Figu e 2g. While he TT-CO in ensi y
s eadily g ows un il sa u a ion a a ound 0.6 L, he adso p ion a
he TBsi es is slowe and app oaches sa u a ion a e he highes
dose used he e (3 L o CO). Close o su ace sa u a ion, he a io
TT/TBis close o 1. This is expec ed om he c(4 ×2)
supe s uc u e and ag ees well wi h a p eceding epo on he
CO adso p ion on P (111) a 200 K.
60
Finally, we no e he
p esence o a sizable amoun o g aphi ic ca bon (“C”) in Figu e
2d, which becomes esidual in he (645) spec um in Figu e 2e,
and comple ely disappea s in he (312) case in Figu e 2 . This
poin s o CO e ace species as pa icula ly sensi i e o beam-
induced dissocia ion. In ac , exposing he CO-sa u a ed (111)
su ace o he beam o app oxima ely 30 min e eals a slow
p e e en ial dissocia ion o CO-TB, since CO-TT emains
cons an as “C” inc eases and TBdec eases wi h beam exposu e
(no shown).
The cen e column o Figu e 2 illus a es he up ake
expe imen o he kinked (645) plane (α= 9.3°, 5-a om-wide
e aces). As seen in Figu e 2e, a peak a 286.4 eV eme ges p io
o any o he ea u e. Simila o P icinals wi h A- and B- ype
s eps,
25,29
and in ag eemen wi h ea lie epo s on kinked P
su aces,
17
we a ibu e his peak o CO adso bed in op
posi ions a he kinked edge (S ep-Top, ST). A highe CO
exposu es, adso p ion a he e ace TTand TBsi es is obse ed.
The co e age e olu ion o Figu e 2h shows how adso p ion a ST
si es slows down a a ound 0.15 L o CO, he poin a which
adso p ion a TTsi es s a s. As in he P (111) su ace up ake,
he occupa ion o TTposi ions is ollowed closely by ha a he
TBsi es. TT-CO g ows as e han TB-CO and s ops a a ound
0.5 L o CO. Howe e , TB-CO con inues o inc ease a a qui e
educed a e up o 0.7 L o CO. A he highes exposu e o his
expe imen (1 L o CO), he su ace is no sa u a ed ye .
The CO adso p ion kine ics on he (312) su ace (α= 22.2°,
2-a om-wide e aces) is depic ed in he igh column o Figu e
2. Again, ST-CO a ises immedia ely a e in oducing CO o he
chambe , ollowed by adso p ion a TTsi es. As seen in he
co e age e olu ion (Figu e 2i), ST-CO sa u a es a a ound 0.6 L
o CO, in con as o TT-CO, which does no ye sa u a e a 1 L
o CO. The inc ease in he sa u a ion dose o CO adso bed a ST
si es is simply explained by i s highe s ep densi y as compa ed o
he (645) plane. A he same ime, he e ec i e e ace leng h o
he (312) su ace is s ongly educed wi h espec o he (645)
plane. Acco dingly, he co e age o TT-CO and TB-CO
dec eases om he (645) plane o he (312) plane. A he
la e , he co e age o TT-CO is e y small, and TBis no e en
obse ed. This ag ees wi h ea ly s udies on he CO adso p ion
by elec on ene gy-loss spec oscopy on he e y same su ace
17
and by XPS on he ully kinked P (201) su ace plane (α= 39.2°,
1-a om-wide e aces).
62
A join analysis o he h ee up ake expe imen s allows us o
es ablish he CO adso p ion sequence as ST→TT→TB,
whe eas he CO deso p ion expe imen s shown in Figu es S2
and S3 o he Suppo ing In o ma ion con i m he expec ed
e e se sequence o deso bing species, i.e., TB→TT→ST.
The e o e, he impinging CO molecules adso b i s on kinks in
he low co e age egime, and hey deso b om kinks only a e
he CO om he e aces has almos anished. Such sequence is
o impo ance o he CO oxida ion eac ion as i s ac i a ion is
igge ed by he deso p ion o CO. In ac , a sligh ly la ge
ac i i y o he (111) ace compa ed o o he su aces wi h A-
and B-s eps was obse ed be o e he eac ion ligh -o .
14
Fu he mo e, P (111) was ound o igni e ea lie han
P (557).
63
As desc ibed by Rempel e al. o he case o he
NO educ ion,
64
and ollowing Saba ie ’s p inciple, a s ong
adso p ion o eac an s may poison a su ace eac ion.
The e o e, ope ando s udies a e needed o add ess he
ac i a ion o he CO oxida ion in densely kinked su aces,
such as (312) s udied in his wo k.
C 1s α-Scan a CO Sa u a ion. To ully cha ac e ize he
CO species ac oss he en i e cu ed su ace, we mo e he sample
ela i e o he X- ay ligh spo in Δα≈2°s eps and a e
sa u a ing he su ace wi h a 10 L o CO exposu e a 300 K.
Figu e 3a shows he esul ing C 1s in ensi y map, called α-scan,
acqui ed a 90 K o imp o e he ene gy esolu ion. The C 1s α-
scan allows us o clea ly isualize he icinal-angle- a ia ion o
species deduced om he up ake and deso p ion expe imen s a
ACS Ca alysis pubs.acs.o g/acsca alysis Resea ch A icle
h ps://doi.o g/10.1021/acsca al.4c00435
ACS Ca al. 2024, 14, 6319−6327
6321
selec ed angles in Figu e 2. The cu ed su ace was also p obed
by LEED a e CO sa u a ion, as shown in Figu e S1 o he
Suppo ing In o ma ion. A he (111) plane, one ob ains a sha p
c(4 ×2) pa e n ha co esponds o he 0.5 ML CO sa u a ion
co e age a 300 K.
19
The e o e, we can use he C 1s spec um in
he (111) su ace o calib a e he CO co e age ac oss he en i e
cu ed sample. The co esponding O 1s da a o he 10 L CO
dose, as well as o a lowe dose o 0.25 L, can be ound in Figu e
S4 o he Suppo ing In o ma ion. A he (111) su ace, peaks
coming om TTand TBa e esol ed a 532.5 and 531.0 eV,
espec i ely. Howe e , since he STline is oo close o he TT
peak, hese a e e y di icul o esol e.
25
We he e o e eso ed
o he C 1s egion in o de o s udy indi idual CO species on
kinked su aces.
Indi idual C 1s spec a co esponding o he (111), (645),
and (312) su aces a e depic ed in Figu e 3b−d. A he (111)
plane, TTand TBcomponen s a e nea ly obse ed, as well as he
small shoulde s asc ibed o ib a ional exci a ions o CO.
57−59
A he (111) su ace, he a io TT/TBis close o 1, as expec ed
om he c(4 ×2) supe s uc u e.
19
In he (645) and (312)
planes, he imp o ed esolu ion allows us o un eil a double
s uc u e in he kink- ela ed peak, which we asc ibe o CO
adso p ion on op o six- old-coo dina ed P a oms a he kink
edge (ST6, 286.17 eV) and a he eigh - old-coo dina ed P
a oms o he second ow (ST8, 286.34 eV), bo h ske ched in
Figu es 1c and 3g. ST8, ST6, and TBpeaks exhibi almos cons an
binding ene gy all o e he α-scan, whe eas TTsmoo hly shi s
om 286.67 eV a he (111) plane o 286.56 eV a he (312)
su ace, likely e lec ing he change in he a e age s ain o P
a oms wi hin (111) e aces as hey ge na owe .
8
Finally, he
small low-binding ene gy ea u e a 285.8 eV has a simila ene gy
and in ensi y in all h ee spec a and all ac oss he α-scan. Such
lack o dependence on he s ep-densi y is he main eason o
belie e ha his peak is ela ed o CO adso bed a de ec s,
29
disca ding CO ancho ed a e ace-hollow o s ep-b idge si es,
wi h simila binding ene gy.
25,29,65
The co e age e olu ion o indi idual CO species as a unc ion
o αa sa u a ion is shown in Figu e 3e. The shown da a a e he
peak in eg als de e mined om he peak i s pe o med on
indi idual spec a om he αscan. The linea a ia ion is
cha ac e is ic o he cu ed su ace,
10,13
e lec ing he ac ha
he numbe o s ep si es inc ease and e ace si es dec ease
linea ly as a unc ion o α. The in ensi ies om he kink-CO
peaks ST8 and ST6 ise wi h αa an almos iden ical a e,
indica ing a simila occupa ion o he wo si es a he kinked
edge, i espec i e o he s ep densi y. In con as , TT- and TB-CO
Figu e 2. CO up ake a he (111), (645), and (312) P su aces. (a−c) C 1s colo plo s acqui ed du ing CO dosing a he (111), (645), and (312)
su aces on he c-P (645) sample. Expe imen s on he (645) and (312) su aces we e ca ied ou a cons an CO p essu e o 1 ×10−9mba , whe eas o
he (111) plane, a p essu e inc ease o 1 ×10−8mba CO was equi ed o speed up he p ocess. (d− ) Cha ac e is ic spec a and i ing lines a low
( op) and high (bo om) CO exposu es o each plane. (g−i) Co e age e olu ion o each CO species as a unc ion o CO exposu e. TT, TB, and ST
s and o CO adso bed as Te ace-Top, Te ace-B idge, and S ep-Top si es, as ske ched in Figu e 1. The dashed black lines ep esen he g aphi ic
ca bon (“C”) con ibu ion, while he solid black line co esponds o he o al CO co e age. The measu emen s we e pe o med a a pho on ene gy o
370 eV and 300 K.
ACS Ca alysis pubs.acs.o g/acsca alysis Resea ch A icle
h ps://doi.o g/10.1021/acsca al.4c00435
ACS Ca al. 2024, 14, 6319−6327
6322
dec ease a di e en pace. This beha io is also ound in close-
packed A- ype icinal su aces
14
and will be discussed below.
F om he co e ages de i ed om he α-scan, we may es ima e
he e ec i e size o e aces and kinked s eps, i.e., he po ion o
he su ace ha is co e ed by e ace-like (TT, TB) and s ep-like
(ST6, ST8) CO species, using he so-called W-model (see e 10
and he Suppo ing In o ma ion o a ull desc ip ion and
de ailed analysis). In he W-model, all s ep species a e con ined
wi hin a s ipe o wid h Wa ound s ep edges, which emains
cons an as he s ep densi y inc eases. As a consequence, he
in ensi y o s ep-like species is expec ed o inc ease linea ly as a
unc ion o α, while e ace-like species dec ease wi h i as he
e aces na ow. The e o e, o he Wmodel, we will conside
he o al s ep (ST6 + ST8) and e ace (TT+ TB) con ibu ions,
ep esen ed in Figu e 3 , and i hei linea a ia ion, using ΘT0
= 0.5 ML, he sa u a ion co e age a he (111) su ace, as a single
i ing pa ame e . The i e u ns he e ec i e s ep size W= 4.3 ±
0.1 Å, ske ched in Figu e 3g, as well as ΘS0= 0.71 ±0.02 ML, i.e.,
he local co e age wi hin he W- egion. F om he la e , we
s aigh o wa dly deduce ha app oxima ely one CO molecule
adso bs pe kink a om (see he Suppo ing In o ma ion), i.e.,
he e is a ull CO occupa ion o he kinked edge a all icinal
angles. Full occupa ion a 300 K is also ound in, e.g., Ni(100)
icinals,
66
and also in he close-packed P (332) and P (557)
su aces bu wi h CO p essu es in he mba ange.
67
We
conclude ha kinked s eps may accommoda e a signi ican ly
highe amoun o CO as compa ed o close-packed s eps a a
educed p essu e. Due o he high CO-co e age a he uppe
kink edge, one could expec a la ge inc ease o he o al CO
co e age wi h he icinal angle α. Howe e , he unde s ep egion
emains CO-deple ed, which compensa es o he high CO
co e age a kinks, esul ing in and leads o a sligh inc ease o he
o al CO co e age wi h α.
The CO-co e ed icinal planes ac oss he c-P (645) sample
show no LEED spo s o he han hose a ising om o de ed
mona omic s ep a ays, simila o B- ype bu con a y o A- ype
P icinals.
29
Howe e , wi h he in o ma ion ex ac ed om he
e olu ion o indi idual species o Figu e 3e and he W-model, we
may s ill pos ula e he s uc u al adso p ion model o he (645)
plane ske ched in Figu e 3g. P ows a e sequen ially illed by CO
molecules om he uppe kink edge and owa d he inne
e ace, i s in TTsi es and nex in TBposi ions, de eloping a c(4
×2)-like supe s uc u e. The e o e, CO ancho ing a TTis
a o ed o e ha a TB, hence explaining he as e decay o TB
wi h αobse ed in Figu e 3e. In eali y, he sequen ial illing
om he s ep edge and inside he same e ace p oposed in
Figu e 3g does no change he c(4 ×2)-4CO densi y a each
e ace, al hough i may sligh ly inc ease he o al α-dependen
co e age due o he p oximi y o he i s occupied TTsi e in he
lowe e ace. This small co e age inc ease is indeed de ec ed in
he o al in ensi y cu e o Figu e 3 . Finally, bo h ΘT(α) and
ΘS(α) de ia e om linea i y abo e α> 18°in Figu e 3e. This
indica es ha local co e ages, hence adso ba e s uc u es a ound
s eps and e aces, a y a densely kinked su aces ha ea u e
na ow e aces, such as he (312) plane.
O 1s α-Scan a O Sa u a ion. A e he igni ion o he CO
oxida ion in P -like me als, he su ace o he ca alys is ypically
co e ed by oxygen species ha a e eac i e owa d CO2
p oduc ion.
3
To cha ac e ize he O laye in he P -kinked
planes, we sa u a e he c-P (645) sample wi h a 8 L O2dose a
300 K. The co esponding α-scan is shown in Figu e 4a, and
selec ed O 1s spec a a ele an su aces appea in Figu e 4b.
Measu emen s we e pe o med a 90 K, which led o a small
buildup o CO om he esidual gas du ing he acquisi ion o he
spec a. A such empe a u es, CO does no eac wi h he
oxygen adso bed on P bu a he s icks o he su ace.
68
Howe e , i a simila expe imen is pe o med a 300 K (Figu e
Figu e 3. C 1s α-scan a CO sa u a ion. (a) C 1s in ensi y colo plo ac oss he cu ed c-P (645) c ys al a e exposu e o 10 L CO a 300 K. (b−d)
Selec ed spec a a he (111), (645), and (312) su aces, espec i ely, oge he wi h hei co esponding i s. Fo each species (TT, TB, ST6, and ST8),
highe binding ene gy sa elli es a e added o accoun o ib a ional losses. The small low-binding ene gy peak (black illing) peak has a cons an
in ensi y ac oss he cu ed c ys al and is assigned o CO adso bed a de ec s. Pho oemission spec a we e eco ded a 90 K and a a pho on ene gy o
370 eV. (e, ) CO co e age a ia ion o indi idual and o al CO species as a unc ion o α, ex ac ed om he i o indi idual spec a o he α-scan in (a).
A small amoun o “C” a ound 284 eV, simila o ha o he de ec s, was also obse ed. (g) CO laye s uc u e a he (645) plane, as de i ed om he
da a analysis. A s eps, a sligh shi om pu e a op si es is sugges ed, in o de o minimize epulsion. Lines in ( ) a e i s o da a using he W-model ha
ende s he e ec i e size o he kinked s eps W, as indica ed in (g).
ACS Ca alysis pubs.acs.o g/acsca alysis Resea ch A icle
h ps://doi.o g/10.1021/acsca al.4c00435
ACS Ca al. 2024, 14, 6319−6327
6323

S5 o he Suppo ing In o ma ion), an O co e age educ ion is
obse ed as compa ed o he esul s acqui ed a 90 K as he
esidual CO emo es some o he oxygen a oms om he su ace
by o ming CO2.
The O 1s spec um o he (111) plane con ains a single,
asymme ic peak a 529.7 eV, which co esponds o
chemiso bed a omic O in cc hollow si es (O cc).
68
As con i med
by LEED (no shown), O a oms a ange in a 0.25 ML, p(2 ×2)-
O s uc u e a he P (111) su ace.
32,69
The e o e, he 1s
in ensi y o he O a his c ys al posi ion is used o co e age
calib a ion. A he (645) su ace, he in ensi y o O cc shi s om
529.7 o 529.6 eV and eaches i s maximum in ensi y. The
binding ene gy posi ion keeps dec easing wi h αup o he (312)
plane, exhibi ing a he same ime an in e media e in ensi y
be ween hose achie ed a he (645) and (111) ace s. This
sugges s ha O a oms ancho ed a h ee- old-coo dina ed
su ace cc si es in bo h s ep edges and e aces (see Figu e 1c)
con ibu e o he O cc peak, wi h i s binding ene gy shi
e lec ing he s ep/ e ace occupa ion a io. In ac , ou da a
ag ees wi h he O cc in ensi y inc ease and peak shi obse ed
be ween P (111) and P (332),
40
and also wi h ea lie s udies
epo ing he adso p ion o O a cc si es in B-s eps.
41,45−47
In addi ion o he p esence o O cc, wo small con ibu ions
appea a 528.8 and 530.7 eV in he (645) plane, bo h g owing in
in ensi y in he densely s epped (312) plane. The e o e, hese
ea u es co espond o di e en oxygen species ancho ed a
s eps. The lowe binding ene gy peak a 528.8 eV poin s o he
p esence o chemiso bed oxygen. No simila ea u e was
obse ed in UHV condi ions o he P (332) and P (553)
su aces wi h close-packed B-s eps,
14,40,48
al hough i was
de ec ed o he P (223) ace wi h squa e {100} mic o-
ace s.
14,48
Since oxygen is epo ed o adso b a b idge si es a
{100} s eps,
41,45−47
we he e o e asc ibe his peak o O
chemiso bed a he b idge si es o he {100} mic o ace in he
kinked s ep (OK). Howe e , OKexhibi s a shi owa d lowe
binding ene gy as compa ed o O cc. This would be indica i e o
an inc ease in he coo dina ion numbe o he chemiso bed
oxygen,
70
esul ing in o adso p ion a he squa e si es o he
squa e A-s ep ins ead o b idge si es. We canno con i m his
scena io wi h ou expe imen al da a se and ollow he
assigna ion o O adso bed a b idge si es. Howe e , gi en he
p oximi y be ween squa e and b idge si es a he {100}
mic o ace s, we belie e ha OKis likely displaced om a pu e
b idge geome y owa d he posi ion o he squa e si e, in a
b idge-like con igu a ion. On he o he hand, he 530.7 eV
emission is assigned o oxygen si ing in 1D “4O”-like s ipes
along he s ep edges.
40,48,49
Such O si e occupa ions occu igh
a e he chemiso p ion p ocess.
40,48,49
The small amoun o
“4O” implies ha only a small ac ion o he P kinked su aces
de elops 1D “4O”-like chains ac oss he kinked edge, in
ag eemen wi h obse a ions in P (332),
40
P (553),
48
and
P (533).
49
The ene gy o “4O” is close o ha o adso bed
OH.
71
Howe e , a peak simila o “4O” was obse ed du ing CO
oxida ion a ound 1 mba in close-packed P icinal su aces
14
and in he kinked P (531) a e annealing in O2in UHV.
18
Unde such condi ions, he p esence o OH g oups is unlikely.
Ne e heless, we do no disca d a small con ibu ion om OH
g oups o he “4O” in ensi y, pa icula ly a 90 K. Bo h he alues
o he OKand “4O” a e ske ched in Figu e 1.
To gain mo e quan i a i e insigh s in o he di e en adso bed
species, we i all indi idual spec a in he α-scan o Figu e 4a.
The α-dependen O 1s in ensi y (exp essed in MLs) ob ained
o each peak and he o al O co e age is shown in Figu e 4c. As
expec ed o s ep-like species, he co e age o bo h he OKand
he “4O”-like species g ows linea ly as a unc ion o |α|. In
con as , O cc does no exhibi any α-dependen e ace-like
dec easing end bu e eals a sha p co e age inc ease om 0.25
o 0.35 ML in he α= 0−10° ange, ollowed by a smoo h
dec ease abo e α= 10°. Such nonlinea , α-dependen
occupa ion o O cc si es e lec s he double s ep- e ace
con ibu ion o he O cc peak discussed abo e. I is in e es ing
o no e ha he s eep inc ease in he in ensi y o he O cc peak
goes in pa allel wi h he apid a enua ion o he LEED pa e n
away om he (111) di ec ion. The la e becomes uzzy and
shows no signa u e o s ep-o de ing in icinal planes. This
sugges s ha , in he p esence o O a oms, kinked s ep edges
oughen,
72
allowing a concen a ion o O cc species (s eps +
e aces), highe han 0.25 ML. The o al O co e age (O cc +
“4O” + OK) almos doubles om he (111) plane (0.25 ML) o
he (312) edge o he sample (0.46 ML) a α= 22°. I is in ac
expec ed ha he oxygen co e age o open s epped su aces is
la ge as compa ed o he (111) plane upon simila ea -
men s,
18,40,44,48,49,73
e lec ing he highe eac i i y o s eps.
Finally, he oxygen species obse ed o P (332)
40
and
P (531)
18
we e epo ed o be signi ican ly ac i e owa d he
CO oxida ion. Gi en ha we ound simila oxygen s ep species
Figu e 4. O 1s α-scan sa u a ion o he c-P (645) su ace. (a) O 1s α-scan acqui ed a e O2dosing o 8 L a 300 K and subsequen cooling o 90 K. (b)
Indi idual spec a a he (111), (645), and (312) su aces wi h line i ing. O cc, “4O”, and OKs and o chemiso bed O a cc hollow si es, he “4O”-like
1D s ipes along he s ep edges, and chemiso bed O a b idge si es o kinked edges (see he ex and Figu e 1). The high binding ene gy ea u es ( ed
illed peaks) co espond o esidual CO, buil up o e he measu ing ime. (c) Co e age a ia ion as a unc ion o α o sepa a e O species and hei
sum, as ex ac ed om he i o all indi idual spec a in he α-scan. Expe imen s we e ca ied ou a a pho on ene gy o 650 eV.
ACS Ca alysis pubs.acs.o g/acsca alysis Resea ch A icle
h ps://doi.o g/10.1021/acsca al.4c00435
ACS Ca al. 2024, 14, 6319−6327
6324
in hese kinked su aces, ou esul s p edic a highe ac i i y o
he CO oxida ion a oxygen-co e ed P kinked planes compa ed
o ha in he la (111) plane.
■CONCLUSIONS
The CO and O2adso p ion on kinked P (111) icinals has been
s udied using a cu ed c ys al su ace wi h he P (645) plane (α
= 9.3°, 5-a om-wide e aces) in he cen e o he sample,
allowing p obe o icinal su aces beyond he densely packed
P (312) ace (α= 22.2°, 2-a om-wide e aces). The cu ed
su ace allows o a sys ema ic analysis o he a ie y o species
obse ed a s eps and e aces upon he sepa a e adso p ion o
CO and O2. We demons a e ha CO p edomina ely adso bs a
he kinked edges a low co e ages, and only a e he s eps a e
nea sa u a ion, he adso p ion a he e aces begins. The
con a y was obse ed du ing deso p ion expe imen s, which
e eals a highe adso p ion ene gy o CO a kinks as compa ed o
(111) e aces. In addi ion, ou da a shows how CO ully
sa u a es he kinked edges wi h oughly one molecule pe s ep
a om, which may u n in o a s ong poisoning o he s eps du ing
CO oxida ion condi ions. O2adso p ion expe imen s e eal a
signi ican ly highe oxygen co e age a icinal su aces wi h
kinked s eps as compa ed o P (111) e aces. This e ec is
pa ly due o s ep-edge oughening and pa ly due o he
p esence o h ee addi ional s ep-like oxygen species, i.e., O
chemiso bed a b idge-like P si es o he {100} mic o ace and
cc posi ions o he {111} mic o ace a he kinks, and oxygen
o ming 1D oxide chains, which g ow also along he s eps. The
highe co e age and adso p ion ene gy o CO a kinks poin
owa d a highe igni ion empe a u e, while he la ge O
co e age a kinks may indica e an inc eased eac i i y unde CO
oxida ion condi ions.
■ASSOCIATED CONTENT
*
sı Suppo ing In o ma ion
The Suppo ing In o ma ion is a ailable ee o cha ge a
h ps://pubs.acs.o g/doi/10.1021/acsca al.4c00435.
LEED and P 4 co e le el o he clean and CO-sa u a ed
(111), (645), and (312) P su aces; C 1s and O 1s
e olu ion du ing CO deso p ion expe imen s a e su ace
sa u a ion wi h 10 L CO a he same su aces; O 1s α-
scans a 90 K a e a 0.25 and 10 L CO dose, and a 300 K
a e 50 L O2dose; and addi ional de ails on he W-model
(PDF)
■AUTHOR INFORMATION
Co esponding Au ho
J. En ique O ega −Cen o de Física de Ma e iales CSIC/UPV-
EHU-Ma e ials Physics Cen e , San Sebas ián 20018, Spain;
Depa amen o Física Aplicada, Uni e sidad del País Vasco,
San Sebas ián 20018, Spain; Donos ia In e na ional Physics
Cen e, San Sebas ián 20018, Spain; o cid.o g/0000-
0002-6643-806X; Email: [email p o ec ed]
Au ho s
Fe nando Ga cía-Ma ínez −Cen o de Física de Ma e iales
CSIC/UPV-EHU-Ma e ials Physics Cen e , San Sebas ián
20018, Spain; P esen Add ess: Deu sches Elek onen-
Synch o on DESY, No kes aβe 85, Hambu g, 22607,
Ge many;o cid.o g/0000-0003-4299-3875
Elia Tu co −Cen o de Física de Ma e iales CSIC/UPV-EHU-
Ma e ials Physics Cen e , San Sebas ián 20018, Spain;
P esen Add ess: Nano ech@su aces Labo a o y, Empa−
Swiss Fede al Labo a o ies o Ma e ials Science and
Technology, Uebe lands asse 129, Dubendo , 8600,
Swi ze land;o cid.o g/0000-0002-6437-9334
F ede ik Schille −Cen o de Física de Ma e iales CSIC/UPV-
EHU-Ma e ials Physics Cen e , San Sebas ián 20018, Spain;
o cid.o g/0000-0003-1727-3542
Comple e con ac in o ma ion is a ailable a :
h ps://pubs.acs.o g/10.1021/acsca al.4c00435
No es
The au ho s decla e no compe ing inancial in e es .
■ACKNOWLEDGMENTS
We acknowledge inancial suppo om g an s PID2020-
116093RB-C44 and PID2019-107338RB-C6-3, unded by he
Spanish MCIN/AEI/10.13039/501100011033 and by “ERDF
A way o making Eu ope”, he Basque Go e nmen (G an IT-
1591-22), and he Dipu ación Fo al de Gipuzkoa (Gipuzkoa
Nex p og am). We acknowledge Ele a Sinc o one T ies e o
p o iding access o i s synch o on adia ion acili ies, and we
hank E. Tosi and P. Laco ig o assis ance in using beamline
Supe ESCA. The esea ch leading o his esul has been
suppo ed by he p ojec CALIPSOplus unde g an ag eemen
730872 om he EU F amewo k P og amme o Resea ch and
Inno a ion HORIZON 2020. Open Access unding p o ided by
Uni e si y o Basque Coun y.
■REFERENCES
(1) E l, G. Reac ions a Solid Su aces; John Wiley & Sons, Inc.:
Hoboken, NJ, USA, 2009.
(2) Somo jai, G.; Li, Y. In oduc ion o Su ace Chemis y and Ca alysis,
2nd ed.; John Wiley & Sons, 2010.
(3) F eund, H. J.; Meije , G.; Sche le , M.; Schlögl, R.; Wol , M. CO
oxida ion as a p o o ypical eac ion o he e ogeneous p ocesses.
Angew. Chem., In . Ed. 2011,50, 10064−10094.
(4) Van Sp onsen, M. A.; F enken, J. W.; G oo , I. M. Su ace science
unde eac ion condi ions: CO oxida ion on P and Pd model ca alys s.
Chem. Soc. Re . 2017,46, 4347−4374.
(5) Esposi o, D. Mind he gap. Na . Ca al. 2018,1, 807−808.
(6) Vendelbo, S. B.; Elkjæ , C. F.; Falsig, H.; Puspi asa i, I.; Dona, P.;
Mele, L.; Mo ana, B.; Nelissen, B. J.; Van Rijn, R.; C eeme , J. F.;
Kooyman, P. J.; Hel eg, S. Visualiza ion o oscilla o y beha iou o P
nanopa icles ca alysing CO oxida ion. Na . Ma e . 2014,13, 884−890.
(7) Pa k, J. Y.; Somo jai, G. A. Cu en T ends o Su ace Science and
Ca alysis; Sp inge New Yo k: New Yo k, NY, 2014.
(8) Wal e , A. L.; Schille , F.; Co so, M.; Me e, L. R.; Be am, F.;
Lobo-Checa, J.; Shipilin, M.; Gus a son, J.; Lundg en, E.; B ión-Ríos, A.
X.; Cab e a-San elix, P.; Sánchez-Po al, D.; O ega, J. E. X- ay
pho oemission analysis o clean and ca bon monoxide-chemiso bed
pla inum(111) s epped su aces using a cu ed c ys al. Na . Commun.
2015,6, 8903.
(9) an Len , R.; Au as, S. V.; Cao, K.; Walsh, A. J.; Gleeson, M. A.;
Juu link, L. B. F. Si e-speci ic eac i i y o molecules wi h su ace
de ec s- he case o H2dissocia ion on P . Science 2019,363, 155−157.
(10) Ga cia-Ma inez, F.; Schille , F.; Blombe g, S.; Shipilin, M.;
Me e, L. R.; Gus a son, J.; Lundg en, E.; O ega, J. E. CO
chemiso p ion on icinal Rh(111) su aces s udied wi h a cu ed
c ys al. J. Phys. Chem. C 2020,124, 9305−9313.
(11) Ga cia-Ma inez, F.; Die ze, E.; Schille , F.; Gajdek, D.; Me e, L.
R.; Ge icke, S. M.; Ze e be g, J.; Albe in, S.; Lundg en, E.; G önbeck,
H.; O ega, J. E. Reduced Ca bon Monoxide Sa u a ion Co e age on
Vicinal Palladium Su aces: he Impo ance o he Adso p ion Si e. J.
Phys. Chem. Le . 2021,12, 9508−9515.
(12) Schille , F.; Ilyn, M.; Pé ez-Dies e, V.; Escude o, C.; Huck-I ia ,
C.; Ruiz del A bol, N.; Hagman, B.; Me e, L. R.; Be am, F.; Shipilin,
ACS Ca alysis pubs.acs.o g/acsca alysis Resea ch A icle
h ps://doi.o g/10.1021/acsca al.4c00435
ACS Ca al. 2024, 14, 6319−6327
6325
M.; Blombe g, S.; Gus a son, J.; Lundg en, E.; O ega, J. E. Ca aly ic
Oxida ion o Ca bon Monoxide on a Cu ed Pd C ys al: Spa ial
Va ia ion o Ac i e and Poisoning Phases in S a iona y Condi ions. J.
Am. Chem. Soc. 2018,140, 16245−16252.
(13) Ga cia-Ma inez, F.; Rämisch, L.; Ali, K.; Waluyo, I.; Bode o, R.
C.; P a , S.; Villa -Ga cía, I. J.; Wal e , A. L.; Hun , A.; Pé ez-Dies e, V.;
Ze e be g, J.; Lundg en, E.; Schille , F.; O ega, J. E. S uc u e Ma e s:
Asymme ic CO Oxida ion a Rh S eps wi h Di e en A omic Packing.
J. Am. Chem. Soc. 2022,144, 15363−15371.
(14) Ga cia-Ma inez, F.; Ga cía-Fe nández, C.; Simono is, J. P.;
Hun , A.; Wal e , A.; Waluyo, I.; Be am, F.; Me e, L. R.; Shipilin, M.;
P a , S.; Blombe g, S.; Ze e be g, J.; Gus a son, J.; Lundg en, E.;
Sánchez-Po al, D.; Schille , F.; O ega, J. E. Ca aly ic Oxida ion o CO
on a Cu ed P (111) Su ace: Simul aneous Igni ion a All Face s
h ough a T ansien CO-O Complex. Angew. Chem., In . Ed. 2020,59,
20037−20043.
(15) Tu ano, M. E.; Juu link, L. B. F.; Gillum, M. Z.; Jamka, E. A.;
Killelea, D. R. S uc u al Inhibi ion o Sil e Su ace Oxida ion. J. Phys.
Chem. C 2021,125, 14702−14708.
(16) Au as, S. V.; Juu link, L. B. Recen ad ances in he use o cu ed
single c ys al su aces. P og. Su . Sci. 2021,96, 100627.
(17) McClellan, M. R.; Gland, J. L.; McFeeley, F. Ca bon monoxide
adso p ion on he kinked P (321) su ace. Su . Sci. 1981,112, 63−77.
(18) Held, G.; Jones, L. B.; Seddon, E. A.; King, D. A. E ec o Oxygen
Adso p ion on he Chi al P {531} Su ace. J. Phys. Chem. B 2005,109,
6159−6163.
(19) No on, P.; Da ies, J.; Jackman, T. Absolu e co e ages o CO and
O on P (111); Compa ison o sa u a ion CO co e ages on P (100),
(110) and (111) su aces. Su . Sci. 1982,122, L593−L600.
(20) Toyoshima, R.; Yoshida, M.; Monya, Y.; Suzuki, K.; Amemiya,
K.; Mase, K.; Mun, B. S.; Kondoh, H. A high-p essu e-induced dense
CO o e laye on a P (111) su ace: A chemical analysis using in si u
nea ambien p essu e XPS. Phys. Chem. Chem. Phys. 2014,16, 23564−
23567.
(21) Kim, J.; Noh, M. C.; Doh, W. H.; Pa k, J. Y. In Si u Obse a ion o
Compe i i e CO and O2Adso p ion on he P (111) Su ace Using
Nea -Ambien P essu e Scanning Tunneling Mic oscopy. J. Phys. Chem.
C2018,122, 6246−6254.
(22) Longwi z, S. R.; Schnad , J.; Ves e gaa d, E. K.; Vang, R. T.;
Lægsgaa d, E.; S ensgaa d, I.; B une, H.; Besenbache , F. High-
co e age s uc u es o ca bon monoxide adso bed on P (111) s udied
by high-p essu e scanning unneling mic oscopy. J. Phys. Chem. B 2004,
108, 14497−14502.
(23) Hops e , H.; Ibach, H. Adso p ion o CO on P (111) and P
6(111) ×(111) s udied by high esolu ion elec on ene gy loss
spec oscopy and he mal deso p ion spec oscopy. Su . Sci. 1978,77,
109−117.
(24) B and , R.; G eenle , R. G. The a angemen o CO adso bed on
a P (533) su ace. Chem. Phys. Le . 1994,221, 219−223.
(25) T änkenschuh, B.; F i sche, N.; Fuh mann, T.; Papp, C.; Zhu, J.
F.; Denecke, R.; S ein uck, H. P. A si e-selec i e in si u s udy o CO
adso p ion and deso p ion on P (355). J. Chem. Phys. 2006,124, 1−10.
(26) Luo, J. S.; Tobin, R. G.; Lambe , D. K.; Fishe , G. B.; Dimaggio,
C. L. CO Adso p ion Si e Occupa ion on P (335) - a Quan i a i e
In es iga ion Using TPD and EELS. Su . Sci. 1992,274, 53−62.
(27) Xu, J.; Ya es, J. T. Te ace wid h e ec on adso ba e ib a ions: a
compa ison o P (335) and P (112) o chemiso p ion o CO. Su . Sci.
1995,327, 193−201.
(28) C eighan, S. C.; Muke ji, R. J.; Bolina, A. S.; Lewis, D. W.; B own,
W. A. The adso p ion o CO on he s epped P {211} su ace: A
compa ison o heo y and expe imen . Ca al. Le . 2003,88, 39−45.
(29) T änkenschuh, B.; Papp, C.; Fuh mann, T.; Denecke, R.;
S ein uck, H. P. The dissimila wins - a compa a i e, si e-selec i e in
si u s udy o CO adso p ion and deso p ion on P (322) and P (355).
Su . Sci. 2007,601, 1108−1117.
(30) Gland, J. L.; Sex on, B. A.; Fishe , G. B. Oxygen in e ac ions wi h
he P (111) su ace. Su . Sci. 1980,95, 587−602.
(31) S eininge , H.; Lehwald, S.; Ibach, H. On he adso p ion o CO
on P (111). Su . Sci. 1982,123, 264−282.
(32) Puglia, C.; Nilsson, A.; He nnäs, B.; Ka is, O.; Bennich, P.;
Ma ensson, N. Physiso bed, chemiso bed and dissocia ed O2on P
(111) s udied by di e en co e le el spec oscopy me hods. Su . Sci.
1995,342, 119−133.
(33) Ma e e , N.; S a ke, U.; Ba bie i, A.; Döll, R.; Heinz, K.; Van
Ho e, M.; Somo jai, G. Reliabili y o de ailed LEED s uc u al analyses:
P (111) and P (111)-p(2 ×2)-O. Su . Sci. 1995,325, 207−222.
(34) Mo ensen, K.; Klink, C.; Jensen, F.; Besenbache , F.; S ensgaa d,
I. Adso p ion posi ion o oxygen on he P (111) su ace. Su . Sci. 1989,
220, L701−L708.
(35) S a ke, U.; Ma e e , N.; Ba bie i, A.; Döll, R.; Heinz, K.; Van
Ho e, M.; Somo jai, G. A low-ene gy elec on di ac ion s udy o
oxygen, wa e and ice adso p ion on P (111). Su . Sci. 1993,287−288,
432−437.
(36) Léga é, P. In e ac ion o oxygen wi h he P (111) su ace in wide
condi ions ange. A DFT-based he modynamical simula ion. Su . Sci.
2005,580, 137−144.
(37) De a ajan, S. P.; Hinojosa, J. A.; Wea e , J. F. STM s udy o high-
co e age s uc u es o a omic oxygen on P (111): p(2 ×1) and P oxide
chain s uc u es. Su . Sci. 2008,602, 3116−3124.
(38) Hawkins, J. M.; Wea e , J. F.; As hagi i, A. Densi y unc ional
heo y s udy o he ini ial oxida ion o he P (111) su ace. Phys. Re . B
2009,79, 125434.
(39) Hanselman, S.; McC um, I. T.; Ros , M. J.; Kope , M. T.
The modynamics o he o ma ion o su ace P O2s ipes on P (111) in
he absence o subsu ace oxygen. Phys. Chem. Chem. Phys. 2020,22,
10634−10640.
(40) Wang, J. G.; Li, W. X.; Bo g, M.; Gus a son, J.; Mikkelsen, A.;
Pede sen, T. M.; Lundg en, E.; Weissen iede , J.; Kliko i s, J.; Schmid,
M.; Hamme , B.; Ande sen, J. N. One-dimensional P O2a P s eps
Fo ma ion and eac ion wi h CO. Phys. Re . Le . 2005,95, 256102.
(41) Feibelman, P. J.; Esch, S.; Michely, T. O. O Binding Si es on
S epped P (111) Su aces. Phys. Re . Le . 1996,77, 2257−2260.
(42) Ra , A.; Ma sushima, T. Deso p ion and dissocia ion o oxygen
admolecules on a s epped pla inum (533) su ace. Su . Sci. 1994,318,
89−96.
(43) Wang, H.; Tobin, R. G.; Lambe , D. K.; DiMaggio, C. L.; Fishe ,
G. B. Adso p ion and dissocia ion o oxygen on P (335). Su . Sci. 1997,
372, 267−278.
(44) Winkle , A.; Guo, X.; Siddiqui, H.; Hagans, P.; Ya es, J. Kine ics
and ene ge ics o oxygen adso p ion on P (111) and P (112)- A
compa ison o la and s epped su aces. Su . Sci. 1988,201, 419−443.
(45) Jacobse, L.; Den Dunnen, A.; Juu link, L. B. The molecula
dynamics o adso p ion and dissocia ion o O2on P (553). J. Chem.
Phys. 2015,143, 014703.
(46) Feibelman, P. J.; Ha ne , J.; K esse, G. Vib a ions o O on s epped
P (111). Phys. Re . B 1998,58, 2179−2184.
(47) Slji ancanin, Z.; Hamme , B. Oxygen dissocia ion a close-
packed P e aces, P s eps, and Ag-co e ed P s eps s udied wi h
densi y unc ional heo y. Su . Sci. 2002,515, 235−244.
(48) Bandlow, J.; Kaghazchi, P.; Jacob, T.; Papp, C.; T änkenschuh,
B.; S ebe , R.; Lo enz, M. P. A.; Fuh mann, T.; Denecke, R.; S ein uck,
H. P. Oxida ion o s epped P (111) s udied by x- ay pho oelec on
spec oscopy and densi y unc ional heo y. Phys. Re . B 2011,83,
174107.
(49) Gun he , S.; Scheibe, A.; Bluhm, H.; Hae ecke , M.; Kleimeno ,
E.; Knop-Ge icke, A.; Schlögl, R.; Imbihl, R. In si u X- ay pho oelec on
spec oscopy o ca aly ic ammonia oxida ion o e a P (533) su ace. J.
Phys. Chem. C 2008,112, 15382−15393.
(50) Mcclellan, M. R.; Gland, J. L.; Mc eely, F. R. Oxygen Adso p ion
on he Kinked P (321) Su ace. S ud. Su . Sci. Ca al. 1983,14, 213−
218.
(51) McClellan, M. R.; McFeely, F.; Gland, J. L. Molecula and a omic
oxygen adso p ion on he kinked P (321) su ace. Su . Sci. 1983,124,
188−208.
(52) Iwasawa, Y.; Mason, R.; Tex o , M.; Somo jai, G. A. The
eac ions o ca bon monoxide a coo dina i ely unsa u a ed si es on a
pla inum su ace. Chem. Phys. Le . 1976,44, 468−470.
ACS Ca alysis pubs.acs.o g/acsca alysis Resea ch A icle
h ps://doi.o g/10.1021/acsca al.4c00435
ACS Ca al. 2024, 14, 6319−6327
6326
(53) Ab ami, A.; Ba naba, M.; Ba is ello, L.; Bianco, A.; B ena, B.;
Cau e o, G.; Chen, Q.; Cocco, D.; Comelli, G.; Con ino, S.; DeBona,
F.; Di Fonzo, S.; Fa a, C.; Fine i, P.; Fu lan, P.; Galimbe i, A.;
Gambi a, A.; Giu essi, D.; Godnig, R.; Ja k, W.; Lizzi , S.; Mazzolini, F.;
Melpignano, P.; Oli i, L.; Paolucci, G.; Pugliese, R.; Qian, S.; Rosei, R.;
Sand in, G.; Sa oia, A.; e al. Supe ESCA: Fi s beamline ope a ing a
ELETTRA. Re . Sci. Ins um. 1995,66, 1618−1620.
(54) New ille, M.; S ensi zki, T.; Allen, D. B.; Inga giola, A. L. M. F. I.
T. Non-Linea Leas -Squa e Minimiza ion and Cu e-Fi ing o Py hon;
Zenodo, 2014.
(55) Doniach, S.; Sunjic, M. Many-elec on singula i y in X- ay
pho oemission and X- ay line spec a om me als. J. Phys. C: Solid S a e
Phys. 1970,3, 285−291.
(56) Shi ley, D. A. High- esolu ion x- ay pho oemission spec um o
he alence bands o gold. Phys. Re . B 1972,5, 4709−4714.
(57) Su ne , S.; Sock, M.; Ramsey, M.; Ne ze , F.; Wiklund, M.; Bo g,
M.; Ande sen, J. CO adso p ion on Pd(111): a high- esolu ion co e
le el pho oemission and elec on ene gy loss spec oscopy s udy. Su .
Sci. 2000,470, 171−185.
(58) Föhlisch, A.; Wassdahl, N.; Hassels öm, J.; Ka is, O.; Menzel,
D.; Ma ensson, N.; Nilsson, A. Beyond he Chemical Shi :
Vib a ionally Resol ed Co e-Le el Pho oelec on Spec a o Adso bed
CO. Phys. Re . Le . 1998,81, 1730−1733.
(59) Smedh, M.; Beu le , A.; Rams ik, T.; Nyholm, R.; Bo g, M.;
Ande sen, J.; Duschek, R.; Sock, M.; Ne ze , F.; Ramsey, M.
Vib a ionally esol ed C 1s pho oemission om CO abso bed on
Rh(111): he in es iga ion o a new chemically shi ed C 1s componen .
Su . Sci. 2001,491, 99−114.
(60) Kinne, M.; Fuh mann, T.; Whelan, C. M.; Zhu, J. F.; Pan ö de ,
J.; P obs , M.; Held, G.; Denecke, R.; S ein uck, H. P. Kine ic
pa ame e s o CO adso bed on P (111) s udied by in si u high
esolu ion x- ay pho oelec on spec oscopy. J. Chem. Phys. 2002,117,
10852−10859.
(61) Cudok, A.; F oi zheim, H.; Schulze, M. Low- empe a u e
adso p ion kine ics o CO on P (111) de i ed om nonequilib ium
ime- esol ed elec on-ene gy-loss spec oscopy measu emen s. Phys.
Re . B 1993,47, 13682−13686.
(62) Lang, J.; Masel, R. An XPS s udy o ni ic oxide, ca bon monoxide
and oxygen adso p ion on P (210). Su . Sci. 1986,167, 261−270.
(63) McC ea, K. R.; Pa ke , J. S.; Somo jai, G. A. The ole o ca bon
deposi ion om CO dissocia ion on pla inum c ys al su aces du ing
ca aly ic CO oxida ion: E ec s on u no e a e, igni ion empe a u e,
and ib a ional spec a. J. Phys. Chem. B 2002,106, 10854−10863.
(64) Rempel, J.; G eeley, J.; Hansen, L. B.; Nielsen, O. H.; Nø sko , J.
K.; Ma ikakis, M. S ep e ec s on he dissocia ion o NO on close-
packed hodium su aces. J. Phys. Chem. C 2009,113, 20623−20631.
(65) Kinne, M.; Fuh mann, T.; Zhu, J. F.; T änkenschuh, B.; Denecke,
R.; S ein uck, H. P. Coadso p ion o D2O and CO on P (111) s udied
by in si u high- esolu ion x- ay pho oelec on spec oscopy. Langmui
2004,20, 1819−1826.
(66) Sinniah, K.; Do se , H. E.; Reu -Robey, J. E. Chemiso p ion on
s epped me al su aces: CO/ icinal Ni(100). J. Chem. Phys. 1993,98,
9018−9029.
(67) Tao, F.; Dag, S.; Wang, L.-W.; Liu, Z.; Bu che , D. R.; Bluhm, H.;
Salme on, M.; Somo jai, G. A. B eak-Up o S epped Pla inum Ca alys
Su aces by High CO Co e age. Science 2010,327, 850−853.
(68) Kinne, M.; Fuh mann, T.; Zhu, J. F.; Whelan, C. M.; Denecke, R.;
S ein uck, H. P. Kine ics o he CO oxida ion eac ion on P (111)
s udied by in si u high- esolu ion x- ay pho oelec on spec oscopy. J.
Chem. Phys. 2004,120, 7113−7122.
(69) Bjö neholm, O.; Nilsson, A.; Tillbo g, H.; Bennich, P.; Sandell,
A.; He nnäs, B.; Puglia, C.; Ma ensson, N. O e laye s uc u e om
adso ba e and subs a e co e le el binding ene gy shi s: CO, CCH3and
O on P (111). Su . Sci. 1994,315, L983−L989.
(70) Ba aldi, A.; Comelli, G.; Lizzi , S.; Kiskino a, M.; Paolucci, G.
Real- ime X- ay pho oelec on spec oscopy o su ace eac ions. Su .
Sci. Rep. 2003,49, 169−224.
(71) Fishe , G. B.; Gland, J. L. The in e ac ion o wa e wi h he
P (111) su ace. Su . Sci. 1980,94, 446−455.
(72) O ega, J. E.; Vasseu , G.; Pique o-Zulaica, I.; Ma encio, S.;
Valbuena, M. A.; Raul , J. E.; Schille , F.; Co so, M.; Muga za, A.; Lobo-
Checa, J. S uc u e and elec onic s a es o icinal Ag(111) su aces
wi h densely kinked s eps. New J. Phys. 2018,20, 073010.
(73) Lindaue , G.; Léga é, P.; Mai e, G. On he in e ac ion o oxygen
wi h P single c ys als; LEED s udy o s ep coalescence. Su . Sci. 1983,
126, 301−306.
ACS Ca alysis pubs.acs.o g/acsca alysis Resea ch A icle
h ps://doi.o g/10.1021/acsca al.4c00435
ACS Ca al. 2024, 14, 6319−6327
6327