Sulfur-enhanced ethanol dehydrogenation on fully exposed molybdenum clusters catalyst

Ethanol dehydrogenation is of great industrial significance, but remains a challenge to use non-oxidative pathways. In this paper, Mo sites in different states were carefully constructed on sulfur-doped carbon (S-C) by adjusting the thermal treatment conditions, which showed distinct performance in the direct heterogeneous dehydrogenation of ethanol to acetaldehyde and ethyl acetate. Among them, Mo_n/S-C with fully exposed molybdenum clusters anchored by sulfur sites showed the best performance with a space-time yield (STY) of 550 g_acetyl/kg_cat./h and a selectivity of 92 % for the target acetyl product, which can be stable for more than 70 h. The Mo^6 + species with electronic property modulated by sulfur were the active sites for ethanol dehydrogenation. The coordination-dependent catalytic performance was rationalized through possible reaction pathways, which demonstrated the evolution of active species during the reaction.