Effects of potassium additive on the activity of Ru catalyst for acetylene hydrochlorination

Ruthenium and ruthenium-potassium bimetallic catalysts for acetylene hydrochlorination were prepared with RuCl3 center dot H2O and KCl as precursors and active carbon as the support. It is found that Ru-K/SAC catalysts have a higher catalytic performance than Ru/SAC catalysts and the optimal conversion of acetylene over Ru1K1/SAC is 93.4% under the conditions of 170 degrees C, C2H2 hourly space velocity (GHSV) of 180 h(-1), feed volume ratio V(HCl)/V(C2H2) = 1.1. Characterized with BET, TG, TEM, TPR, TPD and XPS, it is indicated that the K additive can promote the formation of more active RuO2 species during the catalyst preparation, but also enhance the ruthenium dispersion of catalysts. In particular, K additive can enhance the reactant adsorption and the product desorption properties of Ru-based catalysts, but also facilitate the function of auxiliary RuCl3 species to inhibit coke deposition.