Hydrogen Production from Methane Cracking by Molten Catalysts: A Review and New Perspectives

A molten-metal catalyst exhibits strong resistance to carbon encapsulation and deactivation, due to its unique physical and chemical properties, demonstrating excellent catalytic activity and stability. This paper overviews recent developments in molten-metal catalysts for methane cracking and hydrogen production. It thoroughly examines the stability of reactors, carbon products, and catalysts for each molten-metal system. The kinetics and mechanism of the catalysts in each system have also been analyzed. Finally, for future development, several recommendations for hydrogen production via methane cracking have been proposed, addressing the following research challenges: (1) gaining a deeper understanding of the active sites and methane conversion process, which can provide crucial guidance for designing high-performance catalysts; (2) fostering the advancement of new reaction interfaces; and (3) attempting to develop a low-eutectic-point molten salt system for chemical vapor deposition reactions. The molten-metal catalyst exhibits strong resistance to carbon encapsulation and deactivation due to its unique physical and chemical properties, demonstrating excellent catalytic activity and stability.