Comparison of cost and performance between traditional and green processes for producing bimetallic carbide based oxygen reduction electrocatalysts

Chemical (ion exchange resin) and biomass (water hyacinth leaves) as carbon precursors are adopted to prepare two kinds of bimetallic carbide (Fe₂MoC)-based catalytic materials. It is found that, compared with the material that use ion-exchange resin as carbon precursor (N–Fe₂MoC-RG), the material that use water hyacinth as carbon precursor (N–Fe₂MoC-WHG) has more advantages in cost, environment protection, synthesis simplicity, and catalytic activity for oxygen reduction reaction (ORR). Therein, the N–Fe₂MoC-WHG as a cathode catalyst displays a half-wave potential of 0.905 V (vs. RHE) for catalyzing ORR in alkaline media, and gets a high peak power density of 1.52 W cm⁻² in alkaline electrolyte membrane fuel cell; moreover, the N–Fe₂MoC-WHG displays higher power-density retention or growth rate at lower relative humidity, higher back pressure, higher working temperature and higher catalyst loading, compared with the N–Fe₂MoC-RG. The N–Fe₂MoC-WHG is one of the most active precious metal-free catalysts reported so far, and its stability is very excellent.