Competing on the same stage: Ru-based catalysts modified by basic ligands and organic chlorine salts for acetylene hydrochlorination

Abstract

To provide references for the search of efficient ligands for acetylene hydrochlorination, various basic ligands with different alkaline gradients have been employed to modify Ru-based catalysts, and a rule that the stronger the alkalinity of the ligand, the better the modification effect is established. The minimum surface electrostatic potential calculated by DFT supported this conclusion and is deemed as a descriptor to predict the modification effect of ligands. Moreover, these ligands and the corresponding organic chlorine salts have been compared on the same stage to determine which of these are superior for modifying Ru-based catalysts. Owing to the cage structures with multiple approachable N sites, [HHMTA]Cl and [HDABCO]Cl performed remarkably better than HMTA and DABCO despite little differences between other organic chlorine salts and corresponding ligands. When efficient ionic liquids in gas–solid reactions were used in gas–liquid reactions, the opposite result was found. It is the viscosity that conceals the role of highly efficient ionic liquids in gas–liquid reactions, which points out a breakthrough for research on gas–liquid reactions in acetylene hydrochlorination.