Direct oxidation of methane to methanol is valuable, but reactive oxygen species over oxidize methane and lower selectivity. Here we report a Rh-Cu heteronuclear dual atom catalyst on nitrogen doped graphite that separates sites and restrains oxygen intermediates, enabling methanol through oxygen insertion into C-H bonds. An encapsulated pyrolysis strategy yields an Rh-Cu-N₆ motif with a Rh-Cu distance of 2.42 Å. Electronic coupling between Rh and Cu induces charge polarization and improves reactant activation. Cu captures active oxygen species, suppressing excessive oxygen insertion and deep oxidation. The catalyst achieves up to 81% methanol selectivity and about threefold higher activity than a single atom Rh catalyst. In situ Fourier transform infrared spectroscopy (FTIR) and density functional theory (DFT) calculations reveal stable oxygen bridged intermediates, Rh-O-O-Cu and Rh-O-Cu. Rh stabilizes methyl intermediates, while Cu restrains nearby oxygen reactivity and directs oxygen insertion into C-H bonds to form methanol.

Nickel and ruthenium catalysts supported on HZSM-5 of different SiO₂/Al₂O₃ ratios were synthesized and their catalytic performance in the selective methanation of CO (CO-SMET) in a CO₂ and H₂ rich gas has been investigated, paying much attention to the effects of catalyst surface acidity on the reaction selectivity. H₂-TPR and XPS were employed to identify the chemical states of nickel on HZSM-5 supports. NH₃-TPD was used to determine the surface acidity of the prepared catalysts. The results show that higher CO methanation activity and selectivity can be obtained on the catalyst with higher surface acidity and a lower SiO₂/Al₂O₃ ratio of the support. The Ni–Ru/HZSM-5 catalyst having a SiO₂/Al₂O₃ ratio of 38 and with 15 wt% Ni and 0.5 wt% Ru loading exhibits the best catalytic performance. At the reaction temperature of 220 °C, this catalyst can reduce CO from 1 vol% to below 50 ppm while keeping the CO selectivity above 90%.