Electroless Nickel-Based Catalyst for Diffusion Limited Hydrogen Generation through Hydrolysis of Borohydride

Abstract

Catalysts based on electroless nickel and bi-metallic nickel-molybdenum nanoparticles were synthesized for the hydrolysis of sodium borohydride for hydrogen generation. The catalysts were synthesized by polymer-stabilized Pd nanoparticle-catalyzation and activation of Al 2 O 3 substrate and electroless Ni or Ni-Mo plating of the substrate for selected time lengths. Catalytic activity of the synthesized catalysts was tested for the hydrolyzation of alkaline-stabilized NaBH 4 solution for hydrogen generation. The effects of electroless plating time lengths, temperature and NaBH 4 concentration on hydrogen generation rates were analyzed and discussed. Compositional analysis and surface morphology were carried out for nano-metallized Al 2 O 3 using Scanning Electron Micrographs (SEM) and Energy Dispersive X-Ray Microanalysis (EDAX). The as-plated polymer-stabilized electroless nickel catalyst plated for 10 min and unstirred in the hydrolysis reaction exhibited appreciable catalytic activity for hydrolysis of NaBH 4 . For a zero-order reaction assumption, activation energy of hydrogen generation using the catalyst was estimated at 104.6 kJ/mol. Suggestions are provided for further work needed prior to using the catalyst for portable hydrogen generation from aqueous alkaline-stabilized NaBH 4 solution for fuel cells.

Boron-Based (Nano-)Materials: Fundamentals and Applications

“…Destabilization of LiBH4 has been widely investigated with the objective to decrease the dehydrogenation temperature, and Zavorotynska et al's contribution concerns the solid solution LiBH4-LiCl [7]. Liquid-state chemical hydrogen storage is also a possible application for alkali borohydrides, but NaBH4 is better than the lithium and potassium counterparts in that case [8]. Other candidates for chemical hydrogen storage are boranes, the simplest candidate being ammonia borane (NH3BH3).…”