Engineering Charge Polarized Au Sites for Low-Temperature Acetylene Hydrochlorination

Cationic gold catalyzed acetylene hydrochlorination represents a classical landmark in eliminating global mercury pollution, but their sustainable implementation is hindered by acetylene-dependence design criteria and high operating temperatures. Herein, a platform of carbon-supported single-atoms Au catalysts (Au/BC and Au/NC) with polarized charge characteristics are developed via engineering Au sites with hosted B, N configurations. The negatively charged Au/BC catalyst unlocks the low-temperature inactivity (413-423K) of the Au/NC catalyst while exhibiting superior catalytic performance in the 433-473K operating temperature range. We confirm that the classical scaling relationships on acetylene can be broken by narrowing the adsorption capacity between acetylene and HCl on Au^δ⁻ sites via facilitating the back-donation of d electrons into the antibonding orbitals of acetylene. Prolonging the durability of Au catalysts is achieved through preceding an additional robust Au^δ⁻ → Au^δ⁺ cycle prior to the classic Au^δ⁺ → Au⁰ route. This work opens a promising avenue for low temperature vinyl chloride production.