Engineering a Highly Active PtMo Bimetallic Catalyst for Low-Temperature Reverse Water Gas Shift

The reverse water gas shift (RWGS) reaction is a promising route for CO2 utilization, providing a versatile syngas component for downstream processes such as methanol synthesis and Fischer–Tropsch chemistry. Low-temperature (<400 °C) RWGS offers reduced energy demand and enables process intensification, yet it remains highly challenging. Herein, we report a PtMo@SiO2 catalyst, synthesized via surface organometallic chemistry (SOMC), that achieves near-equilibrium CO2 conversion at 300 °C (GHSV = 60,000 mL/gcat/h, 1 bar). The catalyst exhibits CO formation rates over 2 orders of magnitude higher than Pt@SiO2 at 200 °C and ca. 30-fold higher at 300 °C. Spectroscopic studies, including CO/CO2–IR, in situ XAS, gas switching, and CO-TPD DRIFTS, reveal that partially reduced Mo(IV) interfacial sites on silica promote CO2 adsorption, while Mo(0) in PtMo alloys facilitates the activation of CO2 and CO desorption, jointly enhancing low-temperature RWGS performance.