Highly Active AuCu-Based Catalysts for Acetylene Hydrochlorination Prepared Using Organic Aqua Regia

Development of a sustainable process for designing and synthesising an active and stable catalyst for hydrochlorination of acetylene is challenging, yet crucial, for industrial vinyl chloride monomer (VCM) production. Herein, direct synthesis of bimetallic AuCu catalysts using organic aqua regia (OAR) preparation methods was investigated. In comparison with conventional aqua regia (AR), bimetallic AuCu catalysts synthesised from OAR exhibit enhanced activity and stability. After careful characterisation of the catalyst samples using X-ray diffraction patterns (XRD), Scanning transmission electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS), and Temperature-programmed desorption (TPD), this observation was justified for the following reasons: 1) the existence of sulphur and nitrogen atoms stabilised the cationic Au active sites, and 2) OAR helped to sustain the function of the Cu promotor by stabilising it. Advanced understanding on the importance of promoter stability has unveiled new perspectives for this research area.