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

Abstract

Ruthenium and ruthenium–potassium bimetallic catalysts for acetylene hydrochlorination were prepared with RuCl₃·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 °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.