Photochemistry-assisted Au/TiO2/AC catalyst synthesis and regeneration for enhancing acetylene hydrochlorination reaction

Abstract

An urgent requirement existed for substituting mercury with non-toxic gold-based catalysts in the industrial hydrochlorination of acetylene to vinyl chloride. Nevertheless, Au-based catalysts were plagued by gradual deactivation, driven by the reduction of active Au+/Au3+ sites and the irreversible aggregation of inactive Au0 sites. Herein, we take advantage of green photochemistry assisted oxidation strategy to develop the eco-friendliness and reversible Au-based catalyst synthesis technology for acetylene hydrochlorination reaction. Compared with the impregnation method that uses harsh media (strong acids and toxic solvents), the photochemically assisted oxidation method utilized titanium dioxide (TiO2) and acetonitrile as photochemical auxiliaries. Free radicals were generated during the synthesis process, which enabled the Au active sites in the 1Au/10TiO2/AC-3 catalyst to stably exist mainly in the oxidized state. The photochemical oxidation strategy promotion Au catalysts gave enhanced activity and stability. Through photochemistry regenerate deactivation 1Au/10TiO2/AC-3 catalyst, its catalytic activity regeneration rate reached 92.2%, and exhibited excellent metal reoxidation and catalysis performance. The photochemistry assisted oxidation open more sustainable and economical perspectives of future research directions for precious metal oxidation regeneration and catalyst carrier oxidation and so on.