Catalytic Combustion of Methane over Noble Metal Catalysts

As one of the cleanest fossil fuel resources, methane is also the second largest greenhouse gas after CO2 owing to its strong greenhouse effect. The direct emission of large quantities of trace and unburned methane causes a serious energy loss and greenhouse effect. Catalytic methane combustion is a promising strategy in eliminating methane slip to address the urgent environmental issue. However, the current methane abatement catalysts still face great challenges in thermal stability, water resistance, and sulfur tolerance. In this review, we focus on the popular noble metal-based catalysts, discuss the distinct reaction mechanisms including the Langmuir-Hinshelwood model, Eley-Rideal model, Mars-van Krevelen model, and two-term mechanisms. The deactivation mechanisms induced by sintering, sulfur, and water on popular Pd-based catalysts are then analyzed. Then, we outline the promotion strategies from two aspects, i.e., construction of a core-shell structure and electronic engineering of the active phase to improve thermal stability and poisoning resistance. Finally, a summary and prospects with an emphasis on the newly developed oxide-metal interfaces and photothermal catalysis for highly efficient methane combustion are addressed.