Novel AuCl3–thiourea catalyst with a low Au content and an excellent catalytic performance for acetylene hydrochlorination

Abstract

In this work, we synthesized a novel non-mercuric catalyst with HAuCl₄·4H₂O and thiourea as precursors, and active carbon (AC) as a support. The synthesized catalyst was applied to acetylene hydrochlorination, and the AuCl₃–thiourea/AC catalyst containing 0.4 wt% Au exhibited a similar catalytic performance to the AuCl₃/AC catalyst containing 1 wt% Au. Based on the characterization results of temperature program reduction and X-ray photoelectron spectroscopy, we proposed that the presence of thiourea in the AuCl₃–thiourea/AC catalyst can enhance the content of active Au^(3−δ)+ (δ = 0, 2) by virtue of the interaction between metallic Au⁰ and thiourea. Strengthening the adsorption of hydrogen chloride can restrain the reduction of Au^(3−δ)+ (δ = 0, 2) to Au⁰.