Effects of N-, P-, or O-containing ligands on gold-based complex catalysts for acetylene hydrochlorination.

• The catalysts were prepared by coordinating the Au precursor with heteroatom ligands. • The adsorption and activation capacity of HCl was improved because of the heteroatom. • N- or P-containing ligands contributed to the anchoring and dispersion of Au species. • P-containing ligand also increased the relative content of active Aun+ species. • O-containing ligands enhanced the activity by weakening the adsorption of acetylene. In line with the fulfillment of international Minamata Convention and the urgent need for developing non-mercury catalysts, Au-L x /AC catalysts were synthesized and evaluated for the hydrochlorination of acetylene. The results showed that the interaction between ligands and Au species contributed to the enhanced catalytic activity with important and different roles of each ligand. Depending on the high electronegativity of heteroatoms, all the prepared catalysts had effectively improved their adsorption and activation capacity of hydrogen chloride. Specifically, the N-containing ligands in catalysts increased the dispersion of Au species and an enhanced adsorption of acetylene was observed. Whilst, the coordination of P-containing ligands with Au can increase the relative content of active Aun+ species and the O-containing ligands rather decreased the adsorption of acetylene. Furthermore, all the prepared Au-L x /AC catalysts showed good stabilities based on the inhibition of the agglomeration of Au components or of coking deposition. [ABSTRACT FROM AUTHOR]