Cu/Sn-β Catalyst Enabling the One-Step Synthesis of Methyl Acetate from Methanol Alone via Dehydrogenation Coupling

Methyl acetate (MA) can be directly synthesized via a methanol dehydrocoupling reaction, which is attractive but urgently calls for a groundbreaking catalyst. Herein, we report a Cu/Sn-β system with Sn–Cu synergistic catalysis, enabling the one-step MA synthesis from methanol alone. Over the 3Cu/Sn-β-30 (Si/Sn molar ratio of 33, Cu loading of 3 wt %), a maximum MA space–time yield of 1.4 molMA kgcat–1 h–1 is obtained with 4.1% methanol conversion and 56.4% MA selectivity at 220 °C. Electron transfer from Cu species to framework-confined Sn occurs and thus increases and stabilizes Cu+ sites. Lewis-acidic Sn(framework)/Cu+ pairs, with the assistance of Cu0 dehydrogenation, can transform a methanol molecule into bridged-adsorbed CH2O*. The C–C coupling of CH2O* with CH3O* on another Sn site proceeds to form CH3CHO* by leaving H on Cu+ and O (C–O bond cleavage of CH3O*) on that Sn site. The CH3CHO* subsequently condenses with CH3O* adsorbed on the Cu0 site to form MA.