CeO₂-supported Pt/Ni catalyst for the renewable and clean H₂ production via ethanol steam reforming

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• 作者：Vincenzo Palma ; Filomena Castaldo ; Paolo Ciambelli ; Gaetano Iaquaniello
• 关键词：Hydrogen ; Ethanol ; Bimetallic ; Steam reforming ; Low temperature
• 刊名：Applied Catalysis B: Environmental
• 出版年：2014
• 出版时间：February, 2014
• 年：2014
• 卷：145
• 期：Complete
• 页码：73-84
• 全文大小：3099 K

文摘

The steam reforming of biomass-derived ethanol is a promising method for hydrogen production. It needs the development of efficient catalysts, especially when the reaction is carried out at temperature lower than 600 ¡ãC. The performances of a bimetallic sample, based on Pt (3 wt. % ) and Ni (10 wt. % ) and supported on CeO₂ were investigated, in terms of activity, selectivity and stability. Very interesting results were obtained in the range 250-600 ¡ãC, even with a stoichiometric water/ethanol molar ratio: the ethanol was completely converted at T ¡Ý 300 ¡ãC, with a products distribution extremely close to the equilibrium calculations. Moreover, the selectivity towards the desired compounds was very high, and as a consequence, the sample showed a very low coke selectivity (<1 % ) and a high stability, that was further improved with higher amount of water in the feed stream. The analysis of the products distribution as a function of contact time (3-600 ms) and temperature (340-480 ¡ãC) and the temperature programmed desorption (TPD) experiments, were used to hypothesize the possible reactions involved, in order to develop a mathematical model, able to simulate the kinetic behaviour of the low temperature-ethanol steam reforming over Pt/Ni/CeO₂. Finally, a possible Pt/Ni/CeO₂ catalyzed reaction pathway at 370 ¡ãC, was formulated, that includes the following steps: ethanol adsorption followed by dehydrogenation to acetaldehyde; intermediate decomposition and reforming to CH₄, CO, H₂ and CO₂; CO-WGS and CO₂ methanation reaction.