Low-Temperature Methanol Synthesis by a Cu-Loaded LaH2+x Electride

Methanol is a key chemical in C1 chemistry and energy carrier. The industrial synthesis of methanol uses a heterogeneous catalyst, Cu/ZnO/Al2O3, under harsh conditions of high temperature and high pressure. Here, we propose a design concept for a catalyst to achieve low-temperature synthesis of methanol and report that Cu-loaded rare-earth hydrides (Cu/REH2+x ) work as effective catalysts for methanol synthesis from CO and H2 at temperatures below 100 °C, where the conventional Cu/ZnO/Al2O3 industrial catalyst does not work well. This catalytic activity is due to negatively charged Cu sites that originate from the highly electron-donating support material and hydride ions directly reactive with CO. The activation energy and turn over frequency for the catalyst are less than half and ∼20 times higher than that for conventional Cu-based catalysts, respectively. The present work demonstrates that anionic electrons with a low work function, the metallic nature of the support material, and hydride ions in the support play key roles for low-temperature methanol synthesis.