Hydrogenation of acetylene-ethylene mixtures on Pd catalysts: computational study on the surface mechanism and on the influence of the carbonaceous deposits

A time-dependent Monte Carlo algorithm was employed to study the effects of carbonaceous surface species on the hydrogenation mechanism of acetylene-e thylene mixtures on a Pd catalyst. Simulations of tail-end and front-end mi xture hydrogenation were performed employing the same set of predetermined event probabilities. The involvement of the steric hindrance of the surface species was essential to simulate the experimental data. The catalyst acti vity and selectivity were promoted or inhibited by different concentrations of surface polymeric species formed along with the hydrocarbon hydrogenati on. Tools to get a new interpretation of the catalytic reaction mechanism a nd an innovative basis to perform catalyst design were suggested by the app roach illustrated.