Nanoscale cha ac e iza ion o Co and Co-B ca aly ic coa ings be o e and
a e ca aly ic es s o he sodium bo ohyd ide hyd olysis
Au ho s: Ana M Bel án (1), M Paladini (1), V Godinho (1), G.M. A zac (1), M.C. Jimenez de Ha o (1),
A Fe nández (1)
1. Ins i u o de Ciencia de Ma e iales de Se illa, (CSIC - Uni . Se illa), Se illa, SPAIN
DOI: 10.1002/9783527808465.EMC2016.5347
Co esponding email: [email p o ec ed]
Keywo ds: Co ca alys s, Hyd ogen s o age, STEM, EELS, ca aly ic coa ings, sodium bo ohyd ide
The use o hyd ogen as a po en ial u u e ene gy ca ie is limi ed due o he p oblems o i s s o age. Hyd olysis
o hyd ogen s o age ma e ials such as sodium bo ohyd ide (NaBH4, SB) has been one o he mos in es iga ed
app oaches o hyd ogen gene a ion. SB is s able in d y ai and combines ligh weigh wi h high hyd ogen
con en (10.8 w %).
NaBH4 + 2H2O → 4H2 + NaBO2 (1)
Al hough spon aneous, he SB hyd olysis ( eac ion 1) needs ca alys s o occu a app eciable a es. Co has
demons a ed o be a good choice because i s comp omise be ween ac i i y and cos . Howe e , i s majo
d awback is ela ed o s abili y: hese ma e ials deac i a e upon cycling. Despi e he g ea numbe o wo ks
epo ing Co and Co-B based ca alys s, he na u e o he ac i e phase and deac i a ion mechanisms a e s ill
unde in ense discussion.
We ha e ecen ly epo ed he p epa a ion o suppo ed Co me allic ca alys s as hin ilms by magne on
spu e ing o sodium bo ohyd ide hyd olysis [1]. Magne on spu e ing is a e y e sa ile echnique used in his
wo k o ab ica e Co and CoB ca aly ic coa ings unde di e en deposi ion condi ions and suppo ed on di e en
subs a es (i.e. silicon and polyme ic memb anes). In his wo k we ha e been able o s udy by elec on
mic oscopy he ca aly ic coa ings as g own on he wi es o he polyme ic memb anes. The s uc u al and
composi ional cha ac e iza ion by SEM and (S)TEM echniques has been pe o med be o e and a e he
ca aly ic es s (19 w % SB in NaOH 4 w %, 90 min eac ion ime). Fig. 1 and 2 show he SEM mo phology o a
Co hin ilm on he polyme ic memb ane be o e and a e he ca aly ic es , espec i ely, showing he g ow h o a
new laye on o he ca alys s upon ope a ion. Fu he nano-analysis o he s uc u e and composi ional
dis ibu ion ha e been pe o med by (S)TEM echniques coupled o EELS. They also e eal he o ma ion o
ibe /nano lake-like nanos uc u es on o he ca aly ic coa ings (Fig. 3 and Fig. 4). Composi ional analysis ha e
poin ed ou he o ma ion o Co-bo a es and mos likely cobal oxide/hyd oxide nano lakes (i.e. CoO(OH)) which
could be he o igin o he leaching and deac i a ion mechanisms o he Co-based ca alys s o he in es iga ed
eac ion.
[1] Paladini, M. e al. Applied Ca alysis B-En i onmen al 2014, 158, 400-409.
This wo k was suppo ed by he Spanish MINECO (p ojec CTQ2012-32519 and CTQ2015-65918), CONSOLIDER
FUNCOAT+ (MAT2015-69035-REDC), Jun a de Andalucía (PE2012-TEP862) and CSIC (PIE201460E018). The
au ho s also acknowledge he Labo a o y o Nanoscopies and Spec oscopies (LANE) a he ICMS o he TEM
acili ies and I. Rosa o he TEM samples p epa a ion. AMB hanks o Talen -Hub P og am unded by he Jun a
de Andalucía and he Eu opean Commission unde he Co- unding o he 7 hF amewo k P og am in he People
P og am (Ma ie Cu ie Special Ac ion).
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Acknowledgemen s:
Re e ences:
SEM image o a Co- hin ilm on polyme ic memb ane
be o e he ca aly ic es .
SEM image o a Co- hin ilm on polyme ic memb ane
a e he ca aly ic es
TEM image o a Co hin ilm suppo ed on polyme ic
memb ane a e he ca aly ic es .
STEM image o a Co hin ilm suppo ed on
polyme ic memb ane a e he ca aly ic es .
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