Cost-Effective Hydrotalcite-Derived Fe-Based Catalysts for Stable and Continuous Catalytic Methane Decomposition

Catalytic methane decomposition (CMD) is a promising technology for CO2-free hydrogen (H2) production and valuable carbon co-product generation. However, stable and continuous CMD operation remains challenging due to rapid catalyst deactivation from carbon accumulation, necessitating further reactor design and development of cost-effective and stable catalysts. Here, we present an economic and environmentally friendly method for preparing Hydrotalcite-derived Fe-based catalysts. The optimal Fe2+7Al3+3-O catalyst achieved a high CH4 conversion efficiency of 63.4% and H2 generation rate of about 30 mL per gram of the catalyst per min at 1.5 h, sustaining 50% conversion over 10 h with a total carbon yield of 9.509 g per gram of the catalyst. The carbon products (i.e., carbon nanotubes (CNTs)) shows that their lengths range from 0.5 to 5 μm and their diameters mainly distribute between 20 and 40 nm. Subsequent acid purification removes aggregated particles, impurities, and residual catalyst, yielding purified carbon products with open end side, improved dispersibility and suitable for battery applications. This work offers solutions for both methane utilization and battery technology while bridging two crucial areas of sustainable energy research.