This study investigates the microscopic mechanism of photocatalytic methane conversion, a crucial process for sustainable methane utilization. Using a combination of real-time mass spectrometry, operando infrared absorption spectroscopy, and ab initio molecular dynamics simulations, the researchers demonstrate that interfacial water species significantly enhance C-H bond activation. Interfacial water hydrates and stabilizes hydrocarbon radical intermediates, preventing overstabilization and dramatically improving methane conversion rates (over 30 times) under wet conditions compared to dry conditions at ambient temperature and pressure. These findings offer crucial insights into the role of interfacial water and provide a foundation for designing efficient non-thermal heterogeneous catalysis for methane conversion.
