Sulfate-Promoted Higher Alcohol Synthesis from CO<sub>2</sub> Hydrogenation
Yanqiu Wang, Xinxin Zhang, Xinlin Hong, Guoliang Liu
Abstract
Sulfur is usually regarded as a catalyst poison for many industrial reactions. Since an increasing number of studies have also reported that sulfate can serve as a promoter for certain reactions, the effects of sulfate on catalysts should be critically treated. Herein, we report a promotion effect of sulfate species on higher alcohol synthesis (HAS) from CO2 hydrogenation over a typical KCuFe-based catalyst. It is found that sulfate modification can regulate the hydrogenation capacity and balance of CO dissociated and nondissociated activation, thus optimizing the reaction network of CO2 hydrogenation to higher alcohols. After optimization, the 0.6S-KCFZ catalyst with a moderate S doping (0.6 wt %) displays the HA selectivity of 22.9% and HA STY of 50.7 mg gcat–1 h–1 under the reaction conditions of 320 °C, 5 MPa, and 3 L gcat–1 h–1. Furthermore, based on the reaction coupling strategy, we combined 0.6S-KCFZ with CuZnAlZr (CO2 reduction to C1 species) to construct a multifunctional catalyst, which showed a superior HAS catalytic performance (173.9 mg gcat–1 h–1 at GHSV of 12 L gcat–1 h–1). This work provides a distinctive example for the insight of sulfate modification on HAS from CO2 hydrogenation.