TY - JOUR
T1 - Catalytic activity of cobalt on nanotextured polymer films for hydrogen production
AU - Malvadkar, Niranjan A.
AU - Sekeroglu, Koray
AU - Dressick, Walter J.
AU - Demirel, Melik C.
N1 - Funding Information:
The authors gratefully acknowledge financial support for this work from the Pennsylvania State University , Wyss Institute for Biologically Inspired Engineering at Harvard , and the Office of Naval Research under the Naval Research Laboratory Core 6.1 Research Program. The authors thank Prof. Aman Haque (Penn State) for providing the patterned substrates.
PY - 2011/10/15
Y1 - 2011/10/15
N2 - We describe the mechanism of cobalt and ligand binding on nanotextured poly(chloro-p-xylylene) (PPX) films as supports for catalytic release of H 2 from alkaline aqueous solutions of sodium borohydride. Cobalt catalysts are prepared on nanotextured PPX substrates via electroless plating using a Sn-free Pd(II) colloid with adsorbed pyridine ligand as an adhesion promoter. Gas physisorption studies on PPX, using N2 and CO 2 as probe gases, indicate the presence of micropores (∼1 to 2 nm width) responsible for the adsorption and non-covalent stabilization of pyridine molecules on the nanotextured surface. The strongly adsorbed pyridine molecules promote Co adhesion onto the PPX surface during subsequent electroless deposition, thereby retaining the metal's catalytic activity for H2 evolution even after multiple reaction cycles. In contrast, conventionally deposited PPX is devoid of any nanotexture and contains fewer micropores capable of stabilizing pyridine adsorption, resulting in poor metallization and catalytic activity for H2 evolution. We also demonstrate the effect of patterning the PPX substrate as a means to further improve the activity of the Co catalyst to achieve H2 evolution rates comparable to those obtained using precious metal catalysts.
AB - We describe the mechanism of cobalt and ligand binding on nanotextured poly(chloro-p-xylylene) (PPX) films as supports for catalytic release of H 2 from alkaline aqueous solutions of sodium borohydride. Cobalt catalysts are prepared on nanotextured PPX substrates via electroless plating using a Sn-free Pd(II) colloid with adsorbed pyridine ligand as an adhesion promoter. Gas physisorption studies on PPX, using N2 and CO 2 as probe gases, indicate the presence of micropores (∼1 to 2 nm width) responsible for the adsorption and non-covalent stabilization of pyridine molecules on the nanotextured surface. The strongly adsorbed pyridine molecules promote Co adhesion onto the PPX surface during subsequent electroless deposition, thereby retaining the metal's catalytic activity for H2 evolution even after multiple reaction cycles. In contrast, conventionally deposited PPX is devoid of any nanotexture and contains fewer micropores capable of stabilizing pyridine adsorption, resulting in poor metallization and catalytic activity for H2 evolution. We also demonstrate the effect of patterning the PPX substrate as a means to further improve the activity of the Co catalyst to achieve H2 evolution rates comparable to those obtained using precious metal catalysts.
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U2 - 10.1016/j.jpowsour.2011.05.071
DO - 10.1016/j.jpowsour.2011.05.071
M3 - Article
AN - SCOPUS:79961031114
SN - 0378-7753
VL - 196
SP - 8553
EP - 8560
JO - Journal of Power Sources
JF - Journal of Power Sources
IS - 20
ER -
