Carbon Dioxide Conversion to Methanol over Size-Selected Cu_4 Clusters at Low Pressures

摘要

The activation of CO_2 and its hydro-genation to methanol are of much interest as a way to utilize captured CO_2. Here, we investigate the use of size-selected Cu_4 dusters supported on Al_2O_3 thin films for CO_2 reduction in the presence of hydrogen. The catalytic activity was measured under near-atmospheric reaction conditions with a low CO_2 partial pressure, and the oxidation state of the clusters was investigated by in situ grazing incidence X-ray absorption spectroscopy. The results indicate that size-selected Cu_4 clusters are the most active low-pressure catalyst for catalytic CO_2 conversion to CH_3OH. Density functional theory calculations reveal that Cu_4 dusters have a low activation barrier for conversion of CO_2 to CH_3OH. This study suggests that small Cu clusters may be excellent and efficient catalysts for the recycling of released CO_2.