Non-oxidative coupling of methane over Mo-doped CeO2 catalysts: Understanding surface and gas-phase processes

Direct catalytic non-oxidative coupling is a promising route for the valorization of abundant methane. Understanding mechanism difficult because reactions at surface catalyst and in gas phase via radicals are important high temperatures employed. Herein, series Mo-doped CeO2 samples with isolated Mo sites were prepared by flame spray pyrolysis method screened their performance The selectivity to value-added C2 hydrocarbons (ethane ethylene) among gas-phase products could reach 98%. During reaction, Mo-oxo species as-prepared reduced convert into (oxy-)carbide species, which act as active methane activation. By varying available catalyst-free volume along length reactor, we studied contribution formation different products. Ethane primary product and, least, part ethylene most benzene formed through chemistry. This work provides insights design efficient catalysts highlights importance reducing free reactor limit secondary reactions.