Study on The Adsorption Behavior of Acetylene on PdmAgn (m+n=2~7) Clusters: A theoretical study

The geometries, stabilities and electronic structures of bare bimetallic PdmAgn clusters (m+n=2~7) and the adsorption behavior of acetylene on the clusters have been investigated by using the Density Functional Theory calculations with four functionals. The obtained results indicate that the addition of Ag atom changes the stability as well as the dimensions of topology of the bimetallic clusters and corresponding C2H2-PdmAgn complexes. Moreover, the Ag atom could passivate the electrons of Pd and the Pd π* back donation to C atom. The structure sensibility is highly related to the coordination number of acetylene and the increase of Ag content will decrease the coordination number. There is an obvious linear correlation between the carbon-carbon bond length change of adsorbed acetylene and the carbon-carbon bond stretching vibration frequency. There is helpful for uncover the adsorption behaver by the spectroscopic detection of C2 species by obtained vibration frequencies.