Low temperature methanol synthesis in alcohol solvent over copper-based catalyst

Alkali formate was a promising replacement for conventional alkoxide to catalyze the concurrent methanol synthesis over copper magnesium (Cu/MgO) catalyst from syngas (CO/H2) in ethanol solvent. The results exhibited that the catalytic activity of the combined alkali metal (X) formate/(Cu/MgO–X) catalyst system was in the order: Na > K > Rb > Li, at the reaction conditions of 433 K and 5.0 MPa. The doping of alkali increased the crystal size of metallic copper in copper magnesium catalyst. An obvious induction period of catalytic activity appeared in the Cu/MgO differently from the Cu/MgO–Na in the presence of HCOONa. Consequently, some reversible interaction was found to exist between alkali formate and copper magnesium surface for the formation of active complex and the production of methanol. Under suitable conditions, the syngas conversion and methanol STY reached to 90% and 46 mol/kg-cat./h. A new solid catalyzed reaction mechanism was also proposed.