Metal-zeolite catalysts promoting low-temperature methane oxidation to oxygenates

Catalytic conversion of methane (CH4) into value-added chemicals provides a viable path to reduce dependency on crude oil. Despite the challenges associated with activating methane’s C–H bond and limiting side reactions, low-temperature oxidation of methane to oxygenates has emerged as a promising approach, often hailed as a “grail reaction”. Zeolite-based metal (metal-zeolite) catalysts facilitate methane oxidation at low temperatures, converting methane into oxygenates while minimizing the complete oxidation to carbon dioxide (CO2). This review highlights recent achievements in metal-zeolite catalysts for methane partial and coupling oxidation. With zeolite as the core, we explore the synthesis methods, metallic active sites, reaction mechanisms, and zeolite descriptors of metal-zeolite catalysts for methane partial oxidation. Additionally, we examine the critical role of mono- and bi-metallic species in metal-zeolite catalysts for methane coupling oxidation with carbon monoxide (CO). Finally, we discuss the challenges and opportunities for metal-zeolite catalysts in methane oxidation under mild conditions, proposing future directions for rational design of metal-zeolite catalysts, revealing reaction mechanisms through operando or in situ techniques, and leveraging artificial intelligence (AI) for enhanced catalytic efficiency.