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 °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. e Pt/Ni sample at 370 °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 H2, 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.