3D Metallic Foams as Catalysts for Hydrolysis and Electrooxidation of Sodium Borohydride

Abstract

Economical non-noble metal catalysts with high activity are needed for the development of systems that use sodium borohydride (NaBH4) as fuel or hydrogen source. In that way, foam-like nanostructured catalysts incorporating transition metals (Ni, Cu, Co and Fe) are prepared by electrodeposition using a simple one-step and fast process, the dynamic hydrogen bubble template. Influence of different metal content on foams morphology is assessed by SEM. Present NaBH4 electrooxidation and hydrolysis studies have the goal of analyzing the catalysts suitability for DBFC and PEMFC systems, respectively. Ni-Cu and Ni-Co bimetallic foams present higher current densities towards borohydride oxidation reaction (BOR) than ternary foams. Ni14Cu26Fe41 foam stands out as the best NaBH4 hydrolysis catalyst for a PEMFC while Ni36Cu46 foam has demonstrated to be the best choice as a BOR catalyst in DBFCs.