Direct synthesis of methyl formate from syngas on Cu–Mn mixed oxide catalyst

Abstract

Cu–Mn mixed oxides with different Cu/Mn molar ratios were prepared by ammonia complexation method, and their catalytic performances have been evaluated for the direct synthesis of methyl formate (MF) from syngas. The catalysts were characterized by N2 adsorption-desorption isotherm, XRD, TEM, SEM, FT-IR, XPS and TPR measurements. Results revel that incomplete spinel of Cu1.5Mn1.5O4, CuO and amorphous Mn species are formed in all Cu–Mn catalysts. The interaction between Cu and Mn in Cu–Mn catalyst delays the reduction of samples compared with pure Cu oxide. For the direct synthesis of MF from syngas, Cu–Mn catalysts showed higher catalytic activities and MF selectivities than pure Cu or Mn oxides. CO conversion increases and MF selectivity decreases with the rise of Cu/Mn ratios in catalysts, which could be attributed to the phase compositions, specific surface areas, and the reducibility of the catalysts.