Photoassisted Dry Reforming of Methane Mediated by a Non-noble Molybdenum–Cobalt Oxide Cation Mo₂CoO₂⁺

Dry reforming of methane (DRM) converts CH₄ and CO₂ to syngas but suffers from high endothermicity and catalyst coking. Developing efficient, non-noble metal catalysts demands atomic-level insights. Here, we combine mass spectrometry and theoretical calculations to investigate the structure and catalytic performance of the bimetallic oxide cluster Mo₂CoO₂⁺ in DRM. Mass spectrometry data confirm a complete catalytic cycle, which proceeds through the sequential cleavage of the four C–H bonds in CH₄ followed by CO₂ activation. The first three C–H bond activations occur in the dark, while the fourth C–H bond activation and subsequent C–O coupling are photoinduced. Density functional theory (DFT) calculations reveal a dynamic synergistic mechanism. The Mo and Co atoms mediate electron transfer for C–H activation via the formation of metal–carbon bonds. Meanwhile, the oxygen ligands are critical for maintaining structural stability and suppressing carbon deposition. Our findings reveal a synergistic, photoenhanced DRM mechanism and establish Mo–Co oxide clusters as a promising, coke-resistant catalyst design.