Role of pore structure and surface functional groups of biocarbon in catalytic methane decomposition for hydrogen production

AbstractCatalytic methane decomposition (CMD) offers a route for hydrogen production without direct CO₂ emissions. Carbon-based catalysts are attractive owing to their low cost and sulfur resistance. However, the roles of intrinsic structural differences among biocarbon in CMD are still not fully understood. Among apricot shell-derived carbon (ASC), walnut shell-derived carbon, and coconut shell-derived carbon, ASC shows the highest catalytic activity and stability. After 150 min at 950 °C, ASC maintains a CH₄ conversion of 32.1%, with an H₂ yield of 20.71 mL·g_cat−1·h−1 and a carbon yield of 0.308 g C·g_cat−1. Characterization results show that the superior performance of ASC arises from its ultramicropore-rich structure (<0.7 nm) and abundant oxygen-containing functional groups. Molecular simulations further confirm that smaller pores, oxygen-containing groups, and Stone-Wales defects enhance CH₄ adsorption. These findings guide the valorization of biomass waste into low-cost catalysts for hydrogen production.