CuCl 2 promoted low-gold-content Au/C catalyst for acetylene hydrochlorination prepared by ultrasonic-assisted impregnation

Efficient and stable N-heterocyclic ketone-Cu complex catalysts for acetylene hydrochlorination: the promotion effect of ligands revealed from DFT calculations

Cu-based catalysts are a promising alternative to toxic mercury catalysts for acetylene hydrochlorination, but their effectiveness is limited due to the poor dispersion and deactivation caused by reduction, agglomeration, and carbon deposition. In this study, the activity and stability of carbon-supported CuCl2 catalysts were largely improved by introducing N-heterocyclic ketones. Remarkably, N-methyl-2-pyridone (NM2P) coordinated Cu-based catalysts exhibited over 95% acetylene conversion with better stability under the reaction conditions of T = 180 °C, GHSV (C2H2) of 80 h-1, and VHCl/VC2H2 = 1.2. The combined results of characterization and exhaustive density functional theory (DFT) calculations revealed that the O-Cu coordination between the NM2P ligand and Cu cation strengthened the combination of reactants and Cu active sites, lowering the key reaction energy barrier, thereby leading to high activity. Meanwhile, the addition of the NM2P ligand significantly inhibited the reduction of Cu2+ to Cu+/Cu0, avoiding the formation of CuCl aggregates and the coking caused by Cu0, enhancing the catalytic stability. Overall, our study provides important insights into the design and optimization of Cu-based catalysts for acetylene hydrochlorination.

Construction of highly dispersed Au active sites by ice photochemical polishing for efficient acetylene hydrochlorination

Compared to traditional Au/AC, ice-photochemical polishing results in atomically dispersed AuClx-like multi-sites, yielding a significantly improved performance of Au/AC-F1I1 catalysts.

A study on the rules of ligands in highly efficient Ru–amide/AC catalysts for acetylene hydrochlorination

The electron donor ability and steric hindrance of substituents on amide ligands jointly affect the modification effect of ligands on ruthenium based catalysts for acetylene hydrochlorination.

Progress and Challenges of Mercury-Free Catalysis for Acetylene Hydrochlorination

Activated carbon-supported HgCl2 catalyst has been used widely in acetylene hydrochlorination in the chlor-alkali chemical industry. However, HgCl2 is an extremely toxic pollutant. It is not only harmful to human health but also pollutes the environment. Therefore, the design and synthesis of mercury-free and environmentally benign catalysts with high activity has become an urgent need for vinyl chloride monomer (VCM) production. This review summarizes research progress on the design and development of mercury-free catalysts for acetylene hydrochlorination. Three types of catalysts for acetylene hydrochlorination in the chlor-alkali chemical industry are discussed. These catalysts are a noble metal catalyst, non-noble metal catalyst, and non-metallic catalyst. This review serves as a guide in terms of the catalyst design, properties, and catalytic mechanism of mercury-free catalyst for the acetylene hydrochlorination of VCM. The key problems and issues are discussed, and future trends are envisioned.

Synthesis of a vinyl chloride monomer via acetylene hydrochlorination with a ruthenium-based N-heterocyclic carbene complex catalyst

Delocalisation and transfer of electrons in the formed IPr–(Ru) synergistically yields a significant improvement in activity with respect to its counterpart.

Demystifying the mechanism of NMP ligands in promoting Cu-catalyzed acetylene hydrochlorination: insights from a density functional theory study

Experimental results and DFT calculations revealed the promoting effect of NMP on catalytic reactivity and the inhibiting effect of NMP on the reduction of Cu²⁺ to Cu⁺ and Cu⁰, respectively.

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.

Carbon-supported perovskite-like CsCuCl3 nanoparticles: a highly active and cost-effective heterogeneous catalyst for the hydrochlorination of acetylene to vinyl chloride

Non-mercuric catalysts in acetylene hydrochlorination reaction have been gained much attention.