Influence of pore structure and surface characteristics of balsa wood-derived activated carbon on hydrogen production from methane decomposition

Abstract

Carbon-based catalysts are highly promising for hydrogen production via methane cracking due to their low cost, high-temperature stability, and resistance to sulfur poisoning. However, their practical application is hindered by several challenges, including difficulty in identifying active sites, complexity in catalyst preparation, and limited stability. In this study, we investigated the effects of surface functional groups and specific surface area on methane adsorption and decomposition using balsa wood-derived activated carbon. Three distinct activation methods were employed to modify the carbon, resulting in variations in surface area and functional group composition. Experimental results demonstrated that optimizing the specific surface area significantly enhances methane conversion, with potassium hydroxide-treated activated carbon achieving a methane conversion rate of 62 % and a hydrogen yield of 57 %, both 20 % points higher than those of unmodified biochar. Molecular dynamics and Monte Carlo simulations revealed that surface oxygen-containing functional groups, particularly carbonyl groups, play a crucial role in promoting methane decomposition by enhancing adsorption and interactions with the catalyst. These findings underscore the importance of optimizing both surface structure and functional groups of activated carbon to improve catalytic performance in methane cracking.