Supported Transition Metals for Catalytic Decomposition of Methane: Advances, Challenges, and Outlook

Methane pyrolysis represents a potentially cost-effective approach for CO2-free hydrogen production. This perspective comprehensively summarizes the current state of methane pyrolysis, specifically compiling carbon yields across a variety of metal–supported catalyst families, i.e., Ni, Co, Fe, and other bimetallic compositions, for comparison purposes. We further discuss carbon-growth mode and the productivity differences observed between tip-growth and base-growth systems based on existing data. Fundamental perspectives on methane activation and carbon transport mechanisms are reviewed in Ni-based systems and are further explored in Fe-based systems. Catalyst deactivation is discussed with respect to two dominant causes: rate imbalances in methane activation vs carbon diffusion and metal fragmentation. The state of the carbon market is given along with emphasis on potential challenges to identify suitable applications for carbon coproducts. Best practices for catalyst productivity reporting are also discussed to enhance comparability in future experimental studies.