The Role of Interstitial Solid Solutions in the Formation of Active Component in Supported Palladium Catalysts for Selective Hydrogenation of Acetylene to Ethylene

The effect of adsorption of the reaction medium components on selective hydrogenation of acetylene to ethylene under the action of supported palladium catalysts is considered. The role of interstitial solid solutions of carbon and hydrogen in palladium, which are formed upon contact of the catalyst with the reaction medium, in the mass-transfer processes between surface and subsurface layer of the active component is revealed. The ratio of activation barriers for ethylene desorption/adsorption processes, which determines the selectivity of acetylene hydrogenation, can change in dependence on the structure of palladium nanoparticles and its electronic state. Therewith, changes in the electronic state affect the energy of activated desorption of ethylene from palladium particles, and their structural features determine the energy of activated adsorption and the subsequent hydrogenation of ethylene to ethane.