The (2Â 1Â 0) surface of intermetallic B20 compound GaPd as a selective hydrogenation catalyst: A DFT study

► Hydrogenation of acetylene selectively catalyzed by the B20-type GaPd compound is investigated. ► The (2 1 0)-surface is the catalytically active surface termination. ► An atomistic scenario for the multi-step hydrogenation process is constructed. ► Reaction centers are triangular configurations of two Ga and one Pd atom. ► Decisive factors for activity and selectivity of the catalyst are discussed.