Effects of various metal doping on the structure and catalytic activity of CoB catalyst in hydrogen production from NaBH4 hydrolysis

Four ternary alloy CoB-based catalysts, including Co-Sn-B, Co-Mn-B, Co-Cr-B and Co-Bi-B, were prepared by chemical reduction method. The effect of Sn, Mn, Cr and Bi dopants on phase structure, surface morphologies, electronic interaction, catalytic activity and activation energies of CoB catalysts investigated in depth. Their catalytic activity in hydrogen production from NaBH4 hydrolysis was compared systematically. Compared with undoped CoB catalyst, it can be found that the doping of Cr and Bi exhibits a significant promoting effect on CoB catalyst by accelerating hydrogen generation rate. Nevertheless, the introduction of Sn and Mn into CoB catalyst only attains a slight increase in hydrogen production rate. The doping concentration of Sn, Mn, Cr, Bi species in CoB was adjusted to respectively check their phase structure and catalytic performance, indicating that there is an optimum doping concentration for each dopant. It can be concluded that the promoting effect of various dopants on catalytic performance can be attributed to crystalline phase, specific surface area and electronic interaction involved in NaBH4 hydrolysis.

Automated summary

Four ternary alloy CoB-based catalysts, including Co-Sn-B, Co-Mn-B, Co-Cr-B and Co-Bi-B, were prepared and their effects on phase structure, surface morphologies, electronic interaction, catalytic activity and activation energies of CoB catalysts were investigated. The catalytic activity in hydrogen production from NaBH4 hydrolysis was compared, showing that doping of Cr and Bi significantly promoted hydrogen generation rate, while doping of Sn and Mn only resulted in slight increase. The optimal doping concentration for each dopant was determined, and it was concluded that their promoting effect on catalytic performance is attributed to crystalline phase, specific surface area and electronic interaction.