Phosphorus-substituted atomically dispersed Rh-N3P1 sites for efficient promotion in CO2 hydrogenation towards ethanol production

Ethanol synthesis through CO₂ hydrogenation has shown great promise in contributing to carbon neutrality. Herein, we for the first time present the phosphorus-substitution of atomically dispersed Rh-N₄ sites for the title reaction. The as-formed Rh-N₃P₁ sites enable the reaction product notably switching from nearly total methanol (91.3%) towards major ethanol (81.8%) with a high TOF of 420.7 h⁻¹. This outstanding promotion in both ethanol formation and CO₂ conversion (69% higher) could be assigned to the donation of electron from P atom effectively weakening C-O bond in CH₃OH* , facilitating its cleavage into CH₃ * , and enabling the coupling between CO* and CH₃ * . The presence of Rh-P site pair assists C-O bond activation with a longer bond length owing to a strong affinity of P atom to O atom in CH₃OH* . This research underscores the importance of tuning the coordination and electronic environment of active metal sites for site pair synergistic catalysis.