(583dm) CO Hydrogenation to Higher Alcohols Over Zn-Mn Promoted Cu-Fe Based Catalyst

Higher alcohols (C₂+OH) synthesis is the challenging area in the field of C1 chemistry. Higher alcohols synthesis from syngas (CO + H₂) , biomass-derived syngas (producing from gasifier that consists of CO, H₂, CO₂, N₂, CH₄ and some small alkanes), syngas derived from coal or natural gas reforming, is an important process for the production of oxygenates fuels, fuel additives and other intermediates for value-added chemical feedstock such as medicine, cosmetic, lubricants, detergents, and polyester. Cu-based catalysts containing metal active toward Fischer-Tropsch synthesis (Fe, Co), such as Cu-Fe or Cu-Co based catalysts, are considered as the most promising catalysts for higher alcohol synthesis from syngas.

In this paper, Zn-Mn promoted Cu-Fe based catalyst was synthesized by the co-precipitation method. Higher alcohols synthesis from syngas was studied in a half-inch tubular reactor system after the catalyst was pretreated by using syngas. Zn-Mn promoted Cu-Fe based catalyst was characterized by SEM-EDS, TEM, XRD, and XPS. The liquid phase products (alcohol phase and hydrocarbon phase) were analyzed by GC–MS and the gas phase products were analyzed by GC. The results showed that Zn-Mn promoted Cu-Fe based catalyst had high catalytic activity and high alcohol selectivity. The maximal CO conversion rate was 72%, and the yield of alcohol and hydrocarbons were also very high. Cu⁰ was the active site for alcohols synthesis, iron carbide was the active site for olefin and paraffin synthesis. The reaction mechanism of higher alcohols synthesis from syngas over Zn-Mn promoted Cu-Fe based catalyst was proposed. Zn-Mn promoted Cu-Fe based catalyst can be regarded as a potential candidate for catalytic conversion of biomass-derived syngas to higher alcohols.