Carbon layer supported nickel catalyst for sodium borohydride (NaBH4) dehydrogenation

In this paper, a nickel (Ni) catalyst with large surface area supported by a graphitic layer is proposed. The graphitic layer is formed on a Ni foil by chemical vapor deposition (CVD) using CH4 as a source. The Ni foil is partially etched by a chemical etchant to increase the surface to volume ratio. The H-2 generation rates of the catalysts for different Ni etching times are measured and their surfaces are observed using an optical microscope. The optimized Ni etching time is 6 h, and the catalyst prepared by 6 h of etching shows an H-2 generation rate of about 600 ml/min.(g metal). The 6-h etched Ni/graphitic layer (Ni/G) is reused five times to confirm durability; it shows a high performance without any degradation. The H-2 generation rate for different concentrations of NaBH4 is measured. The reaction follows first order kinetics, which means that the higher the concentration of NaBH4 is, the faster the H-2 generation is. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.