Hydrogen Oxidation in Alkaline Media: the Bifunctional Mechanism for Water Formation

Abstract Water formation according to Had + OHad →H2O has recently been proposed as an intermediate step during hydrogen oxidation in alkaline solutions. Choosing Ni/Cu bimetallic surfaces as model catalysts, we have investigated the energetics and kinetics of this step in the form of a bifunctional...
Ausführliche Beschreibung

Abstract Water formation according to Had + OHad →H2O has recently been proposed as an intermediate step during hydrogen oxidation in alkaline solutions. Choosing Ni/Cu bimetallic surfaces as model catalysts, we have investigated the energetics and kinetics of this step in the form of a bifunctional mechanism. With the aid of density functional theory, we have identified several reaction paths on such surfaces with very low activation energies, suggesting that this step can be very fast. In all cases, the initial adsorption sites have both nickel and copper atoms as nearest neighbors. We suggest a strategy to find other bifunctional surfaces with good catalytic properties for this reaction. Graphical AbstractA bifunctional mechanism for the formation of water as an intermediate step for hydrogen oxidation is investigated by density functional theory. Using copper/nickel alloys of various compositions as an example, potential energy surfaces are calculated for various reaction paths. On some favorable sites the reaction may be too fast to be observed by electrochemical methods. Ausführliche Beschreibung