Efficient catalysts based on substitutional solid solutions and intermetallic compounds of palladium for acetylene selective hydrogenation to ethylene

Abstract

The features of the catalytic action of bimetals such as Pd-Ag, Pd-Cu, Pd-Au, Pd-Ga, Pd-Zn on the conversion of acetylene to ethylene are considered. Two factors that determine the influence of the second metal on palladium – the ensemble effect (geometric effect) and the ligand effect (electronic effect) were taken into account. The relationship between the parameters obtained using calculation methods and experimentally established characteristics are shown. The calculated parameters are thermodynamic and kinetic parameters of the adsorption interaction of the main components of the reaction medium and intermediates with the catalyst surface, the structure of active ensembles and the experimental ones are the structural parameters of bimetallic phases, the electronic state of their components, and catalytic properties of bimetals. The examples illustrating the possibility of the modifier atoms entering into active ensembles and the participation of the sites formed from modifier atoms in the catalysis of individual elementary stages are presented.