Conversions of carbon monoxide oxidation over Pt-Rh alloy catalysts calculated by a new gas chromatographic technique

Catalytic fractional conversions of carbon monoxide to carbon dioxide over Pt-Rh alloy catalysts in the presence of excess oxygen, under steady-state or non steady-state conditions, as well as corresponding rate constants for the CO oxidation reaction were measured by using the reversed-flow gas chr omatographic technique. From the variation of the conversions with temperat ure, maximum values of conversions were found, which depend on the catalyst nature (Pt content), while from the variation of the rate constants with t emperature, activation energies for the CO oxidation reaction were determin ed, which also depend on the catalyst Pt content. The results suggest a syn ergism between Pt and Rh in the Pt-Rh bimetallic catalysts in accordance wi th previous works, showing that reversed-flow gas chromatography can be use d with simplicity and accuracy for the kinetic study of the CO oxidation re action, which is of technological importance for the control of air polluti on.