Alternative Oxidants for the Catalytic Oxidative Coupling of Methane

摘要

The catalytic oxidative coupling of methane (OCM) to C-2 hydrocarbons with oxygen (O-2-OCM) has garnered renewed worldwide interest in the past decade due to the emergence of enormous new shale gas resources. However, the C-2 selectivity of typical OCM processes is significantly challenged by overoxidation to COx products. Other gaseous reagents such as N2O, CO2, and S-2 have been investigated to a far lesser extent as alternative, milder oxidants to replace O-2. Although several authoritative review articles have summarized OCM research progress in depth, recent oxidative coupling developments using alternative oxidants (X-OCM) have not been overviewed in detail. In this perspective, we review and analyze OCM research results reporting the implementation of N2O, CO2, S-2, and other non-O-2 oxidants, highlighting the unique chemistries of these systems and their advantages/challenges compared to O-2-OCM. Current outlook and potential areas for future study are also discussed.