Catalysts and reaction pathways for dehydrogenation and selective oxidation of methanol to methyl formate

Abstract

Methyl formate is a versatile chemical precursor to a wide range of other important chemicals. It can be synthesized by different routes, among which dehydrogenation and selective oxidation of methanol to methyl formate are particularly attractive, because they are operationally simple and green. Metal catalysts such as Cu and Pd-Zn alloys show good performances in the dehydrogenation reaction, and metal oxides such as MoO3-SnO2 and RuO x /ZrO2, noble metals such as Au and Pd, and their composites, are widely used in the selective oxidation of methanol. We focused on the efficient synthesis of methyl formate, and determined the relationship between the catalyst structures and properties, and the reaction pathways in the dehydrogenation and selective oxidation of methanol. The main factors affecting the reaction pathways and selectivity for methyl formate are discussed in detail. The structures of the formaldehyde species adsorbed on Cu and Pd-Zn alloys surfaces play essential roles in the product selectivities in the dehydrogenation reaction. The secondary reaction rates of the formaldehyde intermediates on supported oxide catalysts and the reactivities of adsorbed oxygen species on noble metals control the selectivities of the methanol selective oxidation. These fundamental insights provide a basis for the design of novel catalysts with specific structures and functions for more efficient conversion of methanol to methyl formate.