Non-Faradaic Electrochemical Modification of the Catalytic Activity of Pt using a CaZr0.9In0.1O3-α Proton Conductor

The effect of non-Faradaic electrochemical modification of catalytic activity (NEMCA) was investigated for the case of C(2)H(4) oxidation on a Pt polycrystalline catalyst film also acting as a working electrode in a galvanic cell of the type: C(2)H(4),O(2), CO(2), H(2)O,Pt vertical bar CaZr(0.9)In(0.1)O(3-alpha) vertical bar Au,C(2)H(4), O(2), CO(2), H(2)O In addition to proton conduction, CaZr(0.9)In(0.1)O(3-alpha) is known to exhibit oxygen and hole conduction. Proton conduction predominates over the temperature range, 380 to 460 degrees C of the present investigation. It was found that negative current application, i.e. proton supply to the Pt catalyst film causes up to 500% reversible enhancement to the rate of C(2)H(4) oxidation. The catalytic rate increase is up to 20,000 higher than the rate, -I/F, of proton supply to the catalyst. The observed phenomena ate discussed within the framework of previous electrochemical promotion (NEMCA) studies.