Suppression and Evaluation of Hydrogen Peroxide Formation on Carbon-Supported Hafnium Oxynitride

摘要

The amount of hydrogen peroxide (H_2O_2) formed on carbon-supported hafnium oxynitride (HfO_xN_y-C) catalyst during oxygen reduction reaction (ORR) was successfully suppressed without a decrease in activity by simply changing the synthesis conditions. A decrease in the ammonia treatment time and flow rate at 1223 K resulted in a decrease in H_2O_2 formation by a factor of 3 at 0.6 V versus a standard hydrogen electrode. Rotating ring-disk electrode voltammogram measurements with various catalyst-layer compositions and catalyst loadings confirmed that ORR proceeded primarily via a 4-electron reaction pathway on HfO_xN_y-C.