Graphitic Carbon Materials from Clean Hydrogen Production for Advanced Energy Storage Systems

Abstract

Catalytic methane pyrolysis (CH4 → 2H2 + C), which directly splits methane into hydrogen and solid carbon, is a promising hydrogen production process with no direct emissions of carbon dioxide. With a mass ratio of hydrogen to solid carbon of 1 to 3, large amounts of carbon materials are generated from the methane pyrolysis process. Developing value-added applications for these solid carbon co-products could eliminate waste generation from the process, bring economic benefits to the process, and significantly offset hydrogen production costs. Herein, graphitic carbon materials were synthesized from catalytic methane pyrolysis and were further purified by a high-temperature thermal treatment or room-temperature electrochemical purification. A comprehensive set of characterization tools investigated their physiochemical properties. Afterward, essential functions of these graphitic carbon materials for energy storage applications were demonstrated in battery systems, which involved conductive additives in manganese dioxide cathodes for zinc-carbon batteries, and electrode active materials for dual-carbon batteries. This opens new energy storage applications for these graphitic carbon materials from catalytic methane pyrolysis, benefiting the broader adoption of the clean hydrogen production process via methane pyrolysis.