HYDROGEN OXIDATION ON GAS-DIFFUSION ELECTRODES FOR PHOSPHORIC-ACID FUEL-CELLS IN THE PRESENCE OF CARBON-MONOXIDE AND OXYGEN

Hydrogen oxidation has been studied on a carbon-supported platinum gas diffusion electrode in a phosphoric aad electrolyte in the presence o f carbon monoxide and oxygen in the feed gas. The poisoning effect of carbon monoxide present in the feed gas was measured in the temperatur e range from 80 to 150 degrees C. It was found that throughout the tem perature range, the potential loss due td the CO poisoning can be redu ced to a great extent by the injection of small amounts of gaseous oxy gen into the hydrogen gas containing carbon monoxide. By adding 5 volu me percent (v/o) oxygen, an almost CO-free performance can be obtained for carbon monoxide concentrations up to 0.5 v/o CO at 130 degrees C, 0.2 v/o CO at 100 degrees C, and 0.1 v/o CO at 80 degrees C, respecti vely.