Density functional study of H2S binding on small cationic AgnAum+ (n + m ⩽ 5) clusters

► The first study to investigate the interaction between H2S and AgnAum+ clusters. ► The H2S binding energy is related to the LUMO energy of bare AgnAum+ clusters. ► AgnAum+ may prefer H2 molecular loss upon H2S reactive collision. ► Alloying makes the Ag atoms more reactive towards H2S and the Au ones less reactive.