A Novel Sustainable Cobalt Catalyst for the Methane Pyrolysis Process

Abstract This study investigates the use of biochar derived from pyrolyzed sewage sludge as a sustainable catalyst support for cobalt in the methane pyrolysis process aimed at clean hydrogen production. Biochar was obtained through fast pyrolysis of sewage sludge at 650°C and characterized for its morphological and textural properties. Catalysts with cobalt supported on biochar were synthesized and compared to conventional cobalt catalysts supported on alumina (Al₂O₃). The catalytic performance was evaluated based on methane conversion, hydrogen production efficiency, and selectivity at temperatures of 750°C, 850°C, and 950°C. Results demonstrate that while Co/Al₂O₃ catalysts exhibit higher maximum conversion and efficiency, Co/biochar catalysts show comparable or slightly better selectivity and significantly improved stability during prolonged operation at 850°C. The biochar-supported catalyst exhibited slower deactivation, attributed to the heterogeneous porous structure mitigating carbon deposition effects. Furthermore, the biochar production process has at least 50% lower greenhouse gas emissions compared to alumina, offering a promising environmental benefit. This research highlights the potential of sewage sludge-derived biochar as a cost-effective, sustainable alternative catalyst support for methane pyrolysis hydrogen production.