Durable PdNi/Al2O3 Catalysts with PdO-NiO and PdO-NiAl2O4 Dual Interfaces for Methane Combustion

Catalytic oxidation is a valuable residual methane removal method, and Pd-based catalysts are the most robust and widely applied system. Yet, they suffer from poor stability in practical applications due to sintering and water poisoning. In this work, we prepared a high-performance PdNi/Al2O3 catalyst with PdO-NiO and PdO-NiAl2O4 dual interfaces. PdNi/Al2O3 showed excellent hydrothermal stability after aging at 750 °C, 10% H2O for 72 h, with the T50 remaining below 315 °C. In addition, compared to bare Pd/Al2O3, PdNi/Al2O3 exhibited a better low-temperature activity with a T50 of 287 °C, rivaling state-of-the-art Pd-based catalysts. Combining structural characterizations and DFT calculations, it was shown that dual interfaces promoted the activation of methane C–H bonds and suppressed the adsorption of surface water/hydroxyl groups and agglomeration of PdO particles. This study has provided new perceptions for exploring the influence of interfacial interactions and offered a route to synthesize high-stability palladium catalysts.