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 H₂ 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 H₂ 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 H₂ 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 H₂ generation is.