DFT Study of Ga Role in Acetylene Semihydrogenation on PdGa(110) Surface

M. SANDOVAL; P. BECHTHOLD; V. ORAZI; E. GONZALEZ; A. JUAN; P. JASEN

San Carlos de Bariloche

Simposio; XXIII Latin American Symposium on Solid State Physics; 2018

Recently, it has been proved that intermetallic compounds formed by transition (Pd and Co) and simple (Ga and Al) metals provide excellent eciency and high selectivity for the hydrogenation of Acetylene to Ethylene. For this reason we have studied that reaction on PdGa(110) surface using density functional theory (DFT) calculations. The reaction C2H2 + H2 → C2H4  is modeled and understood in terms of chemical bonding change. The evolution of electronic structure and electron density plot also shed more light on the role of Pd, Ga, and C2H2 during hydrogenation reactions. This new way of looking at a particular chemical reaction includes the changes in bond order in the diferent reaction steps. Our results reveal that the Ga is necessary part of the active site and not a single spacer. We also found that additional hydrogenation is energetically more expensive than ethylene desorption, which shows that this catalyst has a high selectivity for this process.