Breaking the Conversion-Selectivity Trade-Off in Methanol Synthesis from CO2 Using Dual Intimate Oxide/Metal Interfaces

The selective hydrogenation of carbon dioxide (CO₂) to value-added chemicals, e.g., methanol, using green hydrogen retrieved from renewable resources is a promising approach for CO₂ emission reduction and carbon resource utilization. However, this process suffers from the competing side reaction of reverse water-gas shift (RWGS) and methanol decomposition, which often leads to a strong conversion-selectivity trade-off and thus a poor methanol yield. Here, we report that InO_x coating of PdCu bimetallic nanoparticles (NPs) to construct intimate InO_x/Cu and InO_x/PdIn dual interfaces enables the break of conversion-selectivity trade-off by achieving ∼80% methanol selectivity at ∼20% CO₂ conversion close to the thermodynamic limit, far superior to that of conventional metal catalysts with a single active metal/oxide interface. Comprehensive microscopic and spectroscopic characterization revealed that the InO_x/PdIn interface favors the activation of CO₂ to formate, while the adjacent InO_x/Cu interface readily converts formate intermediates to methoxy species in tandem, which thus cooperatively boosts methanol production. These findings of dual-interface synergies via oxide coating of bimetallic NPs open a new avenue to the design of active and selective catalysts for advanced catalysis.