Activation of silicon towards hydrogen generation by pelletisation

One of the barriers to the use of the silicon-water reaction to generate hydrogen for hydrogen fuel cells in portable devices is the lengthy induction period of the reaction caused by the presence of the native oxide layer on the surface of the silicon. Herein is presented a simple pelleting process which can be used to effectively eliminate the induction period in the reaction of pressed silicon powders with 2 wt% sodium hydroxide solution by means of disrupting the native oxide layer. The activation energy of the reaction was found to be 73 kJ/mol by means of an Arrhenius plot. It was also found that the rate of reaction of hydrogen generation could be enhanced by mixing sodium chloride and sodium polyacrylate with the silicon powder before pressing. [Display omitted] •A lengthy induction period hinders the reaction of Si and water to form hydrogen.•A simple pelleting process can be used to eliminate the induction period.•The Arrhenius activation energy of the reaction was found to be 73 kJ/mol.•Hydrogen generation could be enhanced by addition of NaCl and sodium polyacrylate.