Construction of bifunctional single-atom catalysts on the optimized β-Mo2C surface for highly selective hydrogenation of CO2 into ethanol

Green and economical CO2 utilization is significant for CO2 emission reduction and energy development. Here, the 1D Mo2C nanowires with dominant (101) crystal surfaces were modified by the deposition of atomic functional components Rh and K. While unmodified β­Mo2C could only convert CO2 to methanol, the designed catalyst of K0.2Rh0.2/β-Mo2C exhibited up to 72.1% of ethanol selectivity at 150 °C. It was observed that the atomically dispersed Rh could form the bifunctional active centres with the active carrier β­Mo2C with the synergistic effects to achieve highly specific controlled C–C coupling. By promoting the CO2 adsorption and activation, the introduction of an alkali metal (K) mainly regulated the balanced performance of the two active centres, which in turn improved the hydrogenation selectivity. Overall, the controlled modification of β­Mo2C provides a new design strategy for the highly efficient, low-temperature hydrogenation of CO2 to ethanol with single-atom catalysts, which provides an excellent example for the rational design of the complex catalysts.