Development of A zeolites-supported noble-metal catalysts for CO preferential oxidation: H2 gas purification for fuel cell

Abstract Even traces of CO in the hydrogen-rich feed gas to proton exchange membrane fuel cells (PEMFC) poison the platinum anode electrode and dramatically decrease the power output. In this work, a variety of catalytic materials consisting of noble metals supported on A zeolites were synthesised, characterised and tested under realistic conditions in the quest of a catalyst for the removal of CO via the CO preferential oxidation (CO-PROX) reaction. Pt, Pd and Ru-based catalysts, prepared by wet impregnation and characterised by XRD and HRTEM, were investigated in a fixed bed reactor, by determining CO conversion and selectivity through the outlet concentrations of CO and O2. In contrast to supported Pd and Ru catalysts, Pt-catalysts showed complete CO-conversion and a comparatively high selectivity. The 1% Pt-3A catalyst showed the best performance: it kept the complete CO-conversion in a wide temperature range, showing the highest selectivity for CO oxidation with minimal involvement in side reactions, such as H2 oxidation and RWGS reaction. Experimental data proved that the RWGS outcome is directly related to the support structure. The rather high temperature (≈260 °C) at which complete CO conversion is achieved by the 1% Pt-3A catalyst enables to locate the CO-PROX unit immediately after the low temperature water-gas shift unit of the fuel processor converting hydrocarbons into hydrogen-rich gas.

[1]  Hubert A. Gasteiger,et al.  Kinetics of the Selective CO Oxidation in H2-Rich Gas on Pt/Al2O3☆ , 1997 .

[2]  Guanguang Xia,et al.  Efficient Stable Catalysts for Low Temperature Carbon Monoxide Oxidation , 1999 .

[3]  Volkmar M. Schmidt,et al.  Performance Data of a Proton Exchange Membrane Fuel Cell Using H 2 / CO as Fuel Gas , 1996 .

[4]  Y. Delaval,et al.  Determination of isotherms and initial heat of adsorption of CO2 and N2O in four A zeolites from infrared measurements , 1986 .

[5]  R. Sinkevitch,et al.  Carbon Monoxide Removal from Hydrogen-Rich Fuel Cell Feedstreams by Selective Catalytic Oxidation , 1993 .

[6]  M. Kinne,et al.  Kinetic study of selective CO oxidation in H2-rich gas on a Ru/γ-Al2O3 catalyst , 2002 .

[7]  F. Gracia,et al.  Kinetics, FTIR, and Controlled Atmosphere EXAFS Study of the Effect of Chlorine on Pt-Supported Catalysts during Oxidation Reactions , 2002 .

[8]  Christopher D. Dudfield,et al.  A compact CO selective oxidation reactor for solid polymer fuel cell powered vehicle application , 2000 .

[9]  D. W. Goodman,et al.  CO-free fuel processing for fuel cell applications , 2002 .

[10]  R. Farrauto,et al.  Selective catalytic oxidation of CO in H2: fuel cell applications , 2000 .

[11]  V. Belyaev,et al.  Selective oxidation of carbon monoxide in excess hydrogen over Pt-, Ru- and Pd-supported catalysts , 2003 .

[12]  M. Watanabe,et al.  Removal of carbon monoxide from hydrogen-rich fuels by selective oxidation over platinum catalyst supported on zeolite , 1997 .

[13]  A. I. Kozlov,et al.  Active Oxygen Species and Mechanism for Low-Temperature CO Oxidation Reaction on a TiO2-Supported Au Catalyst Prepared from Au(PPh3)(NO3) and As-Precipitated Titanium Hydroxide , 1999 .

[14]  S. Komarneni,et al.  Nepheline and carnegieite ceramics from A-type zeolites by microwave heating , 2004 .

[15]  K. Poeppelmeier,et al.  Comparison of Pt/KL catalysts prepared by ion exchange or incipient wetness impregnation , 1992 .