화학공학소재연구정보센터
International Journal of Hydrogen Energy, Vol.38, No.16, 6633-6645, 2013
On the activity of bimetallic catalysts for ethanol steam reforming
The performance of CeO2-supported Pt-Ni and Pt-Co catalysts in the low temperature-Ethanol Steam Reforming (ESR) reaction has been evaluated studying the effect of the preparation method (impregnation/coprecipitation) and parameters such as dilution ratio, temperature, water-to-ethanol feed ratio and Gas Hourly Space Velocity (GHSV). The results show that impregnated samples perform better. In particular, the Pt/Ni/CeO2 catalyst starting from 350 degrees C leads to a products distribution very close to the equilibrium calculations, with a low CO content that is ideal for fuel cells devices. In addition, the Co-based catalysts appear attractive in terms of hydrogen yield and coking tendency. For the Pt/Ni sample at 370 degrees C, the analysis of products distributions vs contact time suggests a surface reaction path involving ethanol dissociative adsorption, dehydrogenation to acetaldehyde at short contact time (5-40 ms), followed by decomposition, reforming and CO-WGS reactions, to obtain H-2, CH4, CO2 and CO. The last step is the methanation reaction, occurring at contact times higher than 100 ms, which drives the system to the equilibrium. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.