Reprint of 'Tungsten and nickel tungsten carbides as anode electrocatalysts'

摘要

Tungsten and nickel tungsten carbides were evaluated as the anode catalysts of a polymer electrolyte fuel cell (PEFC). These catalysts were prepared by the temperature-programmed carburization of tungsten and nickel tungsten oxides from 573 to 873-10 73 K in a stream of 20% CH{sub}4/H{sub}2 and kept at temperature for 3 h. The 30% tungsten and nickel tungsten carbides mixed with Ketjen carbon (KC) were evaluated by cyclic voltammetry and linear sweep voltammetry using a rotating disk electrode and electrocatalytic activity (I-V performance) using a single cell. The W1023/KC catalyst achieved a power density of 6.4mW/cm{sup}2 (current density: 15.2mA/cm{sup}2) which corresponded to 5.7% of that achieved by a commercial 20% Pt/C catalyst in a single cell (20% Pt/C: 111.7mW/cm{sup}2) using our setup. From the XRD data, α-W{sub}2C together with a small amount of WC was active during the anodic oxidation. The maximum power density of the 30wt% 873 K-carburized NiW/KC was 8.2mW/cm{sup}2 at the current density of 19.0 mA/cm{sup}2 which was 7.3% of the 20 wt% Pt/C.