Room-Temperature CO₂ Hydrogenation to Methanol over Air-Stable hcp-PdMo Intermetallic Catalyst

CO₂ hydrogenation to methanol is one of the most promising routes to CO₂ utilization. However, difficulty in CO₂ activation at low temperature, catalyst stability, catalyst preparation, and product separation are obstacles to the realization of a practical hydrogenation process under mild conditions. Here, we report a PdMo intermetallic catalyst for low-temperature CO₂ hydrogenation. This catalyst can be synthesized by the facile ammonolysis of an oxide precursor and exhibits excellent stability in air and the reaction atmosphere and significantly enhances the catalytic activity for CO₂ hydrogenation to methanol and CO compared with a Pd catalyst. A turnover frequency of 0.15 h^-1 was achieved for methanol synthesis at 0.9 MPa and 25 °C, which is comparable to or higher than that of the state-of-the-art heterogeneous catalysts under higher-pressure conditions (4-5 MPa).