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Among the vinyl chloride production processes, ethane oxychlorination is the most economical and environment-friendly process but constrained by the lack of high performance catalysts for industrial applications. In this work, FeCl3–KCl/Al2O3 catalysts with different molar ratios of K/Fe were prepared by a co-impregnation method and applied to ethane oxychlorination. The FeCl3–KCl/Al2O3 catalyst with K/Fe = 2 exhibited enhanced catalytic performance with the highest conversion of C2H6 (99.1%) and the best selectivity to C2H3Cl (74%) under the optimal conditions of 400 °C, C2H6 : HCl : air = 1 : 3 : 5.5 (volume ratio) and GHSV = 4560 h−1. It was found that the enhanced catalytic performance could be attributed to the formation of KFeCl4 from KCl and FeCl3 and the change of the reaction process. Besides, KCl is in favor of weakening the interaction between the active species and support. The reduction activation energy of Fe(iii) → Fe(ii) is efficiently reduced by KCl addition. The FeCl3–KCl/Al2O3 catalyst may be a potential catalyst for industry due to its simple composition and convenient preparation. [ABSTRACT FROM AUTHOR]

• CuCr 2 O 4 Spinel is a potential catalyst for ethane oxychlorination. • The Mg2+ doped at the CuCr 2 O 4 A-site exhibites enhanced catalytic activity. • The addition of Mg2+ enhances the reduction ability of Cu (II) to Cu (I). • C 2 H 3 Cl is preferentially desorbed in the transformation of C 2 H 6 in the (1 2 1) plane. A series of novel spinel oxide catalysts, Cu 1− x Mg x Cr 2 O 4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1), for the ethane oxychlorination catalytic reaction were prepared by a sol–gel method, and X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller, H 2 temperature-programmed reduction, O 2 temperature-programmed desorption, and X-ray photoelectron spectroscopy were used to characterize the catalysts. It was found that the enhanced catalytic performance could be attributed to A-site doping of Mg2+ in the CuCr 2 O 4 catalysts. The addition of Mg2+ changes the preferred orientation of the crystal from CuCr 2 O 4 (0 2 0) to Cu 0.6 Mg 0.4 Cr 2 O 4 (1 2 1) and leads to lattice distortions and more surface defect oxygen species in Cu 0.6 Mg 0.4 Cr 2 O 4. The Cu 0.6 Mg 0.4 Cr 2 O 4 catalyst shows optical catalytic performance for ethane oxychlorination, with an average ethane conversion of 95.6% and a vinyl chloride selectivity of 50.2%. Density functional theory results showed that the Cu 0.6 Mg 0.4 Cr 2 O 4 catalyst would enhance the adsorption ability of the crystal (1 2 1) plane for C 2 H 6 , C 2 H 3 Cl, and C 2 H 4. C 2 H 3 Cl is preferentially desorbed in the conversion of reactant C 2 H 6 on the (1 2 1) plane. It is evident that the difference in electron density between C 2 H 3 Cl and C 2 H 4 on the planes contributes to the improvement of Cu 0.6 Mg 0.4 Cr 2 O 4 selectivity. [ABSTRACT FROM AUTHOR]