The effect of steam and hydrogen in promoting the oxidation of carbon monoxide over a platinum on alumina catalyst

Abstract Steam‐ and hydrogen‐induced effects on carbon monoxide oxidation at temperatures below 200°C were studied over an alumina‐supported Pt catalyst. These studies were complemented by measurements of rate expressions and IR spectroscopy. CO oxidation activity over alumina‐supported Pt, Pd and Rh catalysts was found to be strongly promoted by the presence of steam and H 2 in the feed gas. The promotion effect decreased in the order Pi>Pd> Rh. The water‐gas shift reaction did not occur under these experimental conditions. The steam and H 2 enhancement effects are attributed to the weakening of self‐poisoning by CO.