In situ DRIFTS Studies on Cu, Ni and CuNi catalysts for Ethanol Decomposition Reaction

Abstract

Catalyst nanopowders containing copper and nickel were synthesized using solution combustion synthesis method for hydrogen production from ethanol decomposition. Detailed in situ DRIFTS studies were conducted on three catalysts (Cu, Ni and CuNi) between 50 and 400 °C to identify the reaction pathways leading to differences in product selectivity over these catalysts. The catalysts nanopowders were characterized before and after reaction using various techniques (XRD, SEM and TEM) to understand the effect of reaction on catalytically active nanopowders. DRIFTS studies indicate that ethanol decomposition on Cu surface proceeds via acetaldehyde formation at low temperature (200–300 °C), generates ethyl acetate and carbon dioxide at 400 °C. Ni was more selective for methane and carbon monoxide. CuNi catalysts follows a trend similar to Cu catalyst at low temperature producing relatively more stable acetaldehyde intermediate that Ni, however at temperature above 300 °C, it behaves more like Ni catalyst producing only methane and carbon monoxide.