The role of KCl in FeCl3-KCl/Al2O3 catalysts with enhanced catalytic performance for ethane oxychlorination

Article abstract of DOI:10.1039/c7dt01957b

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.