The catalytic oxidation of methane to value-added C1 oxygenates under mild conditions represents an energy-efficient strategy for natural gas utilization, yet remains challenging due to the inherent chemical inertness of methane. Herein, we report a highly efficient catalyst featuring atomically dispersed Pd sites confined within the lattice of mordenite (MOR) for room-temperature methane oxidation using ozone as the oxidant. This catalyst achieves over 99% selectivity toward C1 oxygenates with a high yield of 6.0 mmol gPd-1 h-1 at 25 °C. Comprehensive in situ experiments, microscopic characterizations, and theoretical calculations reveal that the ozone with a strong oxidative potential can be facilely dissociated to reactive oxygen species (O*) on the MOR lattice-confined Pd sites, where methane can be efficiently activated and converted to desirable products. We found that dual-Pd sites possess a higher catalytic performance than the single-Pd sites, which is attributed to the optimized trade-off between the activities for ozone dissociation to O* and C-H cleavage, thereby enabling efficient CH4 conversion.
Dai et al. (Mon,) studied this question.