Qi, Xingzhen; Lin, Tiejun; An, Yunlei; Wang, Xinxing; Lv, Dong; Tang, Zhiyong; Zhong, Liangshu

ACS CATALYSIS

2023, 13,

Qi, Xingzhen; Lin, Tiejun; An, Yunlei; Wang, Xinxing; Lv, Dong; Tang, Zhiyong; Zhong, Liangshu

Constructing highly efficient dual active sites for preferentialformation of higher oxygenates via direct syngas conversion remainsa grand challenge. Herein, we reported that the regulation of oxygenvacancy density of metal-oxide support could effectively promotethe production of oxygenates. Compared with an inert SiO2-supported Co-based catalyst, the rutile TiO2-supportedcatalyst with abundant oxygen vacancies exhibited up to 44.7% CO conversionwith the selectivity and space-time yield (STY) of the oxygenateincreased to 43.4 wt % and 50 mg g(cat.) (-1) h(-1), respectively. Further studies establisheda nearly linear relationship between the density of the oxygen vacancyand the atomic ratio of Co2+/Co-0 or the STYof oxygenated products. Characterization confirmed that the oxygenvacancies not only promote CO adsorption, dissociation, and subsequentlythe carburization of cobalt species to form Co2C but alsocreate a C-rich and H-poor local microchemical environment that benefitsCO associative adsorption and C O bond insertion to form oxygenates.The synergistic effect of oxygen vacancies and the Co-0/Co2C interface site contributed to the observed enhanced performancefor direct syngas conversion to higher oxygenates.