(132b) Pt-Pd/CeO2-Omc Bimetallic Catalysts for Formic Acid Oxidation

Rehman, A., King Fahd University of Petroleum & Minerals
Hossain, M. M., King Fahd University of Petroleum & Minerals
Ahmed, S., King Fahd University of Petroleum & Minerals

The effects of CeO2 modification and variation of Pd/Pt ratios on the performance of PtPd/CeO2-OMC electrocatalysts in oxidation of formic acid is studied. N2 adsorption analysis shows that the CeO2 modification increases the surface area of OMC support from 1005 m2/g to 1119 m2/g.  SEM, XRD and TEM analysis reveal that the presence of CeO2 enhances the uniform dispersion of active metal(s) on the support surface.  Average sizes of the dispersed metal crystals decrease with the increase of Pt mass fraction on CeO2-OMC.  Electrochemical evaluation of CeO2 modified Pd/CeO2-OMC provides 12 % higher anodic current activity than that of unmodified Pd/OMC catalyst.  The peak potential is also shifted more than 83 mV in the negative direction.  In the bimetallic samples, a small amount of Pt with Pd improves the performance of the catalysts significantly. Among the bimetallic catalysts, Pd3Pt1/CeO2-OMC displays superior current density (74.6 mA/cm2), which is 1.61, 1.67 and 28.3 times higher than that of Pd/CeO2-OMC, Pd1Pt3/CeO2-OMC and Pt/CeO2-OMC catalysts, respectively.  The bimetallic Pd3Pt1/CeO2-OMC catalyst also shows persistent activity in extended period of runs without any indication of CO poisoning effects.