Phosphorus-doped carbon supports enhance gold-based catalysts for acetylene hydrochlorination

Abstract

The phosphorus-doped carbon, consisting of phosphate groups in the surface, was prepared using triphenylphosphine as the phosphorus source and assessed as the support of Au catalysts for acetylene hydrochlorination reaction, characterized by FT-IR, XPS, Raman, TEM, BET, etc. This P-doped carbon support can enhance both the acetylene conversion and the selectivity to vinyl chloride monomer (VCM) over Au/SAC catalysts. Over the optimal Au/20% P-SAC-700 catalyst, the acetylene conversion is 99.9% and the selectivity to VCM equals 100% within 23 h of reaction. It is illustrated that the phosphorous groups in the P-doped carbon support, comprised of (PO₄)³⁻and (PO₃)⁻, can interact with the active gold species Au³⁺ and Au¹⁺ so as to improve the dispersibility of catalytic active sites. And in the catalyst Au/20% P-SAC-700 the interactions of phosphorous groups (PO₄)³⁻and (PO₃)⁻ can prevent the reduction of active gold species Au³⁺ and Au¹⁺ into Au⁰, but also retard the coking deposition on the catalyst surface, suggesting that the modulation of phosphorus-dopants in the carbon supports is a promising route to explore efficient non-mercuric catalysts for PVC manufacture.