Abstract
Methane has emerged as an important energy source and chemical feedstock, and thus breakthrough strategies for the direct partial oxidation of CH4 into small oxygenates have been desired. Here, CO-assisted CH4 conversion towards C1 and C2 oxygenates over zeolite-supported single-atom Rh catalysts was demonstrated, and the key role of CO, as an indispensable additive, and the reaction mechanism were experimentally investigated. Step-bystep introduction of the reactants resulted in the formation of stoichiometric amounts of product. Replacement of O2 by H2O2 revealed that gaseous O2 acts as a true oxidant, and CO enhanced the reaction as a ligand. The critical effect of acid sites in the formation of the C2 product was also confirmed. Based on these results, a plausible reaction mechanism was proposed. Finally, a small-pore zeolite, SSZ-13, was found to be superior for the selective production of methanol.
NSTL
Elsevier