Characterization of hydrogen generation for fuel cells via borane hydrolysis using an electroless-deposited Co-P/Ni foam catalyst

Abstract

The effect of an electroless-deposited Co-P/Ni foam catalyst on H(2) generation kinetics in ammonia borane (NH(3)BH(3)) solution and the cyclic behaviour (durability) of the catalyst are investigated. The electroless deposited Co-P is composed of an inner flat layer and outer layer that consists of an aggregate of spherical particles. The H(2) generation rate/projected area of the Co-P/Ni foam catalyst is much higher than that of a Co-P/Cu sheet catalyst. The activation energy (E(a)) for the hydrolysis of NH(3)BH(3) using the Co-P/Ni foam catalyst is calculated to be 48 kJ mol(-1). After the first cycle, the H(2) generation rate decreases dramatically, due to a decrease in surface area caused by the partial separation of spherical Co-P particles. by 16%, due to a decrease in surface area caused by the partial separation of spherical Co-P particles. Between the first and sixth cycles, the H(2) generation rate decreases gradually (by 14%) on account of a decrease in the number of P atoms that create active metallic Co sites on catalytic surface. After six cycles, about 70% of the initial H(2) generation rate remains constant. The study reveals a promising means of hydrogen generation for polymer electrolyte membrane fuel cells. (C) 2009 Elsevier B.V. All rights reserved.