Exceptional CO2 Hydrogenation to Ethanol via Precise Single-Atom Ir Deposition on Functional P Islands.

The thermocatalytic hydrogenation of CO2 to ethanol has attracted significant interest because ethanol offers ease of transport and substantial value in chemical synthesis. Here, we present a state-of-the-art catalyst for the CO2 hydrogenation to ethanol achieved by precisely depositing single-atom Ir species on P cluster islands situated on the In2O3 nanosheets. The Ir1-Px/In2O3 catalyst achieves an impressive ethanol yield of 3.33 mmol g-1 h-1 and a turnover frequency (TOF) of 914 h-1 under 1.0 MPa (H2/CO2 = 3:1) at 180 °C, nearly 8 times higher than that of the unmodified Ir1/In2O3 catalyst. Additionally, at a more industrially relevant pressure of 5.0 MPa, the TOF of the Ir1-Px/In2O3 catalyst can reach up to 2108 h-1, surpassing previously reported catalysts. Combined in-situ characterization and theoretical studies reveal that the hydrogenation process is significantly enhanced by the Ir1-Px entities. Specifically, the Ir atom facilitates CO2 activation and C-C coupling, while the surrounding P island exhibits exceptional H2 dissociation ability. These three steps have been found crucial for the CO2 hydrogenation reaction. This discovery opens new opportunities for the regulation of the microenvironment of current catalysts by providing essential chemical functionalities that enhance intricate and complex reaction processes.