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

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• 作者：Rosso ; Ilaria ; Galletti ; Camilla ; Saracco ; Guido ; Garrone ; Edoardo ; Specchia ; Vito
• 关键词：Pt/Pd/Ru-A zeolite ; CO preferential oxidation ; Return water gas shift
• 刊名：Applied Catalysis B: Environmental
• 出版年：2004
• 出版时间：March 31, 2004
• 年：2004
• 卷：48
• 期：3
• 页码：195-203
• 全文大小：291 K

文摘

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.