Enhanced Stability of Atomically Dispersed Pd Catalysts via Ionic Liquid Layer Deposition for Selective Acetylene Hydrogenation to Ethylene in Excess Ethylene

Abstract

Abstract A series of TiO 2 ‐supported Pd catalysts with different amounts of ionic liquid (IL) were synthesized for the selective hydrogenation of acetylene to ethylene in excess ethylene. CO Fourier transform infrared spectroscopy (FTIR), high‐angle annular dark‐field‐scanning transmission electron microscopy (HAADF‐STEM), and X‐ray photoelectron spectroscopy (XPS) suggested that the Pd species in the catalysts synthesized via the strong electrostatic adsorption (SEA) method exist predominantly as isolated atoms on TiO 2 independent of the presence of the IL. Using a combination of FTIR and XPS, it was found that IL deposition on Pd catalysts induces a change in the electronic structure of atomically dispersed Pd atoms. The IL‐modified catalysts exhibited improved stability in acetylene hydrogenation compared to IL‐free catalysts owing to their higher coke resistance. Thus, this study provides a novel synthetic strategy based on IL deposition for improving the coke resistance and stability of atomically dispersed catalysts.