Properties of alkali-promoted Cu–MgO catalysts and their activity for methanol decomposition and C 2-oxygenate formation

Abstract

The decomposition of CH 3OH in the presence of CO has been investigated over high surface area MgO, Cu–MgO, K–Cu–MgO and Cs–Cu–MgO catalysts. The catalysts were prepared by thermal decomposition of metal salts mixed with palmitic acid. The reduced catalysts had surface areas of 18–74 m 2 g −1 and intrinsic basicities of 4–17 μmol CO 2 m −2. Results revealed that methyl formate was a primary product of CH 3OH decomposition, whereas CO was a secondary product. Although selectivity to C 2 species (ethanol and acetic acid) was low (<5 C-atom %) at the low pressure (101 kPa) conditions of the present study, there was an optimum intrinsic basicity (9.5 μmol CO 2 m −2) at which the selectivity to C 2 species and methyl formate reached a maximum. The role of catalyst basic properties in the formation of C 2 species from CH 3OH is discussed.