Oxygen vacancies boosted Co-Co2C catalysts for higher alcohols synthesis from syngas

Co-Co2C catalyst has attracted much attention as the catalyst for higher alcohols synthesis due to comparatively high C2+OH selectivity. Herein, oxygen vacancies boosted Co-Co2C catalysts were fabricated via an in-situ reduction and topochemical carbonization process of La0.9K0.1Cox Fe1-xO3/ZrO2. The results indicated that abundant oxygen vacancies were introduced into perovskite with the addition of Fe into the B site of perovskite. Under syngas atmosphere, part of Co-0 was topochemical carbonized into Co2C, and Co-Co2C/LaFeO3-ZrO2 catalyst promoted by oxygen vacancies and K2O-La2O3 could be fabricated. No CO adsorption behaviors on Co2C were detected by in-situ CO-DRIFT and a linear correlation between alcohol selectivity and surface oxygen vacancies was observed, which verified that oxygen vacancies were the key active sites for alcohols formation on Co-Co2C catalyst. TPD results indicated that oxygen vacancies provided additional adsorption sites for CO and adjusted the adsorption forms of CO. Under the synergism effect between Co, Co2C and oxygen vacancies, Co-Co2C catalyst with abundant oxygen vacancies exhibited an excellent alcohol selectivity of 57.1 % and an outstanding stability. This work not only verified the in-situ conversation process of perovskite during reduction and reaction, but also revealed the catalytic mechanism of oxygen vacancies promoted Co-Co2C catalyst for higher alcohol synthesis.

Automated summary

In this study, oxygen vacancies enhanced Co-Co2C catalyst was successfully fabricated, and it was found that oxygen vacancies played a crucial role in the formation of higher alcohols on the catalyst. The synergism effect between Co, Co2C, and oxygen vacancies contributed to the excellent alcohol selectivity and stability of the catalyst, providing insights into the catalytic mechanism of oxygen vacancies promoted Co-Co2C catalyst for higher alcohol synthesis.