Mesoporous silica template-derived nickel-cobalt bimetallic catalyst for urea oxidation and its application in a direct urea/H2O2 fuel cell

Abstract

Ni-based catalysts are considered as an efficient anode material for urea fuel cells due to the low cost and high activity in alkaline media. Herein, we demonstrate that Ni-Co bimetallic hydroxide particles with highly porous nanostructures can be synthesized using mesoporous silica nanoparticles as templates. The replicated nanostructures of the Ni-Co hydroxide samples from the mesoporous silica templates are observed. The porous Ni0.8Co0.2(OH)(2) particles exhibited considerably enhanced electro-catalytic activity for urea oxidation reaction by providing a high surface area and fast mass transport for urea oxidation reaction. It is also found that the Co-doping at 20% significantly reduce the overpotential and increase the peak current of urea oxidation reaction. A direct urea/H2O2 fuel cell with the porous Ni0.8Co0.2(OH)(2) as anode material shows an excellent performance with maximum power densities of 11.2 and 25.6 mW cm(-2) at 20 degrees C and 70 degrees C with 0.5 M urea in 5 M KOH, respectively. Thus, this work suggests that the highly porous Ni0.8Co0.2(OH)(2)-derived from the mesoporous silica templates can be used for urea oxidation and as an efficient anode material for urea-based fuel cells. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.