Carbon-supported catalysts for carbon dioxide methanation: A review

Carbon-based materials have attracted significant attention in various catalytic applications. However, they are rarely reported for high-temperature catalytic reactions, owing to their limited thermal stability compared to other common materials such as silica and alumina, especially in oxidation reactions. CO₂ methanation became a pivotal research hotspot due to its ability to contribute to greenhouse gas mitigation. In addition, CO₂ methanation reactions can be carried out below 400 °C in a hydrogen atmosphere, which suits the thermal stability of many modified carbon materials. However, the number of reviews on CO₂ methanation does not match the huge number of the experimental publications on CO₂ methanation particularly reviews on carbon-supported catalysts. Motivated by the paucity of literature, including reviews on carbon-supported catalysts for CO₂ methanation, this review is focused on the catalytic performance of the carbon-supported catalysts of CO₂ methanation. It offers significant comparisons among all reported carbon-supported catalysts, providing a comprehensive study on the effect of the carbonaceous supports, such as graphene, biochar, and carbon nanotubes on the catalytic activity. In addition, it investigates the impact of promoters on the catalytic performance of the carbon-supported catalysts in CO₂ methanation and highlights the preparation methods and their optimized metal compositions that lead to the highest activity and selectivity. We conclude with a brief synopsis on the current challenges and perspectives on the future directions. This study paves the way for broader usage of carbon-supported catalysts for different thermal catalytic applications, not limited to CO₂ methanation.