Development of ionic liquids promoted low content ruthenium catalysts for acetylene hydrochlorination

To achieve the sustainable production of acetylene hydrochlorination, the development of green and efficient mercury-free catalysts is a challenge. Ru-based catalysts are potential alternatives, but they are not applicable due to their high price and poor stability. Herein, we synthesized a series of low loading Ru-based catalysts modified by nitrogen-containing ionic liquids. These catalysts show high activity and stability based on the interaction between nitrogen-containing ionic liquids and Ru species. Among them, 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride modified Ru-based catalyst, 0.3%Ru-N4/AC, exhibits excellent catalytic activity at 180 °C and a GHSV (C2H2) of 170 h-1, with an acetylene conversion of 94.3%. The addition of ionic liquids effectively promotes the dispersion of Ru species and increases the relative content of active Ru species on the activated carbon support. Simultaneously, the addition of ionic liquids also inhibits the reduction of active Ru species and prevents coke deposition, therefore improving the catalyst stability. 0.3%Ru-N4/AC catalyst also exhibits excellent stability over 150 h, demonstrating its potential as a mercury-free catalyst for acetylene hydrochlorination.