Control of Co⁰/Co₂C dual active sites for higher alcohols synthesis from syngas

Dual active sites play a vital role in higher alcohols synthesis (HAS) from syngas and the relative proportion of each active sites may greatly affect the contact boundaries between the dual active sites and the reaction network. Herein, we regulated the ratio of Co⁰/Co₂C dual active sites by changing the content of Na promoter, and investigated the structure-performance relationship of Co⁰/Co₂C for HAS. It was found that both of the catalytic activity and paraffins selectivity increased with the increase of Co⁰/Co₂C ratio, while the formation of olefins was inhibited. However, the oxygenates selectivity exhibited a volcano variation trend. The results suggested that only when the Co⁰/Co₂C ratio was in the appropriate range, the strong synergistic effect of Co⁰/Co₂C dual-site could be obtained, and the CO insertion rate can thus match well with hydrogenation rate and chain-growth rate, which benefited for the oxygenates formation.