The Relative Electrocatalytic Activity of Noble Metals in the Oxidation of Ethylene

A comparative study of the anodic oxidation of ethylene on five noble metal electrodes (Au, Ir, Pd, Pt, Rh) in 1M sulfuric acid at 80°C is reported. Complete oxidation of ethylene to CO2 was observed on Pt, Ir, and Rh. On Au and Pd practically no CO2 could be detected and the main products of the reaction were aldehydes and acetone. The Tafel slopes as well as pH and pressure effects are also found to be different for the two groups of metals. The order of chemical reactivity in the two groups of metal catalysts is Pt > Rh > Ir and Pd > Au. © 1965, The Electrochemical Society, Inc. All rights reserved.