Several gold-based catalysts including Au, Au–La(III), Au–Co(II), and Au–Co(III) were prepared and assessed for acetylene hydrochlorination, combining with characterizations of low-temperature N₂ adsorption/desorption, thermogravimetric analysis, X-ray diffraction, temperature-programmed reduction, inductively coupled plasma-atomic emission spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The best catalytic performance was obtained over Au1Co(III)3/SAC catalysts with an acetylene conversion of 92% and a selectivity to VCM of 99.9%. It is indicated that the additives of Co(III), Co(II) and La(III) are preferential to stabilize the catalytic active Au⁺ species and inhibit the reduction of Au³⁺ to Au⁰ in the preparation process of Au-based/SAC catalysts. The addition of these additives can greatly inhibit the occurrence of coke deposition on the catalyst surface, and also inhibit the catalyst sintering, thereby improving the activity and long-term stability of the Au-based catalysts.

Bimetallic gold–barium catalysts were prepared and assessed for acetylene hydrochlorination, and characterized using low-temperature N₂ adsorption/desorption, thermogravimetric analysis, X-ray diffraction, temperature-programmed reduction/desorption, inductively coupled plasma-atomic emission spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The best catalytic performance is obtained over Au1Ba(II)1/AC catalysts with the acetylene conversion of 98.4% and the selectivity to VCM of 99.9%. It is indicated that the addition of Ba(II) can make Au species disperse well and inhibit carbon deposition on the catalyst surface; Ba(II) additives can enhance the adsorption of reactants on the catalysts but also inhibit the reduction of active gold species during the reaction, consequently augmenting the activity and long-term stability of gold catalysts.

This study describes the decomposition of CO₂ using Dielectric Barrier Discharge (DBD) plasma technology combined with the packing materials. A self-cooling coaxial cylinder DBD reactor that packed ZrO₂ pellets or glass beads with a grain size of 1–2 mm was designed to decompose CO₂. The control of the temperature of the reactor was achieved via passing the condensate water through the shell of the DBD reactor. Key factors, for instance discharge length, packing materials, beads size and discharge power, were investigated to evaluate the efficiency of CO₂ decomposition. The results indicated that packing materials exhibited a prominent effect on CO₂ decomposition, especially in the presence of ZrO₂ pellets. Most encouragingly, a maximum decomposition rate of 49.1% (2-mm particle sizes) and 52.1% (1-mm particle sizes) was obtained with packing ZrO₂ pellets and a 32.3% (2-mm particle sizes) and a 33.5% (1-mm particle sizes) decomposing rate with packing glass beads. In the meantime, CO selectivity was up to 95%. Furthermore, the energy efficiency was increased from 3.3%–7% before and after packing ZrO₂ pellets into the DBD reactor. It was concluded that the packing ZrO₂ simultaneously increases the key values, decomposition rate and energy efficiency, by a factor of two, which makes it very promising. The improved decomposition rate and energy efficiency can be attributed mainly to the stronger electric field and electron energy and the lower reaction temperature.