Facile hydrothermal synthesis of flower-like Co–Mo–S catalysts and their high activities in the hydrodeoxygenation of p-cresol and hydrodesulfurization of benzothiophene

Abstract

Co–Mo–S catalysts were synthesized by a facile hydrothermal synthesis and their activities were tested in the hydrodeoxygenation (HDO) of p-cresol, hydrodesulfurization (HDS) of benzothiophene, and simultaneous HDO of p-cresol and HDS of benzothiophene. When Co/Mo mole ratio in Co–Mo–S was adjusted to 0.3, the catalyst presented a flower-like morphology and exhibited high HDO and HDS activity, which was attributed to its specific structure and the maximum synergy between CoS2 and MoS2. In the HDO of p-cresol, direct deoxygenation (DDO) was the main reaction route and toluene selectivity reached to 97.5%. The hydrogen consumption was markedly cut down. By adding small amount of benzothiophene, p-cresol conversion was enhanced because the produced H2S from the HDS of benzothiophene slowed down the catalyst deactivation. In simultaneous HDO of p-cresol and HDS of benzothiophene, because of the competitive adsorption of reactants on the active sites, both the toluene selectivity and desulfurization degree were lowered compared with the single component reactions.