Encapsulated ruthenium sites in reaction microenvironment-regulated UiO-66 for stable acetylene hydrochlorination

Abstract

Ruthenium (Ru)-based catalysts have been recognized as potential substitutes for mercury in the hydrochlorination of acetylene due to their high initial activity and low cost. However, rapid deactivation limits their industrial application and the agglomeration of active sites is considered as one of the main reasons for deactivation. To overcome this challenge, in this work, we introduced a thermally stable metal–organic framework to encapsulate Ru sites into regular channels successfully, thus enhancing the dispersion of Ru sites. To decrease the diffusion resistance caused by the channels, we partly substituted –H groups with –OH groups in the channels to change the reaction microenvironment. After characterization and simulation, we demonstrated that both the encapsulation strategy and channel regulation were beneficial for increasing the adsorption of reactants, thus obtaining 92.27% conversion of acetylene with a deactivation rate below 0.02% h⁻¹ even when the gas hourly space velocity was at a high level (540 h⁻¹). This work provides a new insight into inhibition of the deactivation of Ru-based catalysts in acetylene hydrochlorination via introducing skeleton materials with regular channels.