Metal on metal oxide platforms for syngas production by chemical looping of methane: status and perspectives

The energy-efficient conversion of methane (CH₄) to syngas represents a transformative pathway for advancing the global hydrocarbon economy. While conventional reforming processes are well established for producing syngas, a key intermediate for high-value fuels and chemicals, chemical looping reforming of methane offers a compelling alternative. By decoupling the reduction and oxidation steps, chemical looping approaches inherently minimize side reactions and enhance product selectivity. This review explores the critical material and economic considerations necessary for the development of robust, energy-efficient chemical looping technologies for dry reforming of methane. Metal oxide-supported catalysts, incorporating noble or transition metals, are the primary catalysts for chemical looping applications. Catalyst performance is governed not only by the intrinsic reactivity of active metals toward CH₄ and CO₂ activation but also by the redox behavior of oxide supports and the interfacial dynamics at the metal–support boundary. Key strategies for improving methane conversion efficiency and ensuring long-term catalyst durability include lowering C–H bond activation barriers, enhancing the oxygen storage capacity of supports, and engineering metal–support interactions to suppress coking and sintering. This article reviews the current challenges and opportunities in methane conversion technology and presents a comprehensive evaluation of catalysts comprising Ni, Fe, Co, and Pt dispersed on CeO₂, ZrO₂, Ce_1-xZr_xO₂, Al₂O₃, SiO₂, and TiO₂ supports, with a parallel focus on economic feasibility and industrial scalability.