Recent progress in single-atom catalysts for thermal and plasma-assisted conversion of methane

Methane (CH₄), a major component of natural gas and a potent greenhouse gas, poses significant environmental and industrial challenges. Catalytic conversion of CH₄ emerges as a crucial strategy, contributing to the production of cleaner energy carriers and the synthesis of valuable product. In this context, single-atom catalysts (SACs) have gained prominence with their superior catalytic properties. This comprehensive review provides an in-depth exploration of SACs for thermal and plasma-assisted conversion of CH₄. The review commences with the distinctive catalytic features exhibited by SACs. Subsequently, detailed discussions are presented on the design strategies and synthesis methods for developing SACs. Furthermore, a comprehensive examination is conducted on physicochemical characterization techniques specific to SACs. Importantly, this review comprehensively outlines the application of SACs for thermal and plasma-assisted conversion of CH₄, encompassing their advantages in facilitating the conversion of CH₄ into high value chemicals, as well as their utilization in various indirect (dry reforming of methane (DRM), steam reforming of methane (SRM) and partial oxidation of methane (POM)), and direct (oxidative routes and non-oxidative routes) CH₄ conversion processes. Additionally, this review delves into the experimental techniques and theoretical research of density functional theory (DFT) to reveal the reaction mechanism of CH₄ conversion on SACs. The synthesis of knowledge culminates in a summary of key findings and forward-looking perspectives. This comprehensive review aspires to provide guidance for the efficient conversion of methane through thermal/plasma catalysis using SACs.