Tuning the Catalytic Activity of Pd Ni ( + = 6) Bimetallic Clusters for Hydrogen Dissociative Chemisorption and Desorption.

Density functional theory was used to study dissociative chemisorption and desorption on Pd Ni ( + = 6) bimetallic clusters. The H dissociative chemisorption energies and the H desorption energies at full H saturation were computed. It was found that bimetallic clusters tend to have higher chemisorption energy than pure clusters, and the capacity of PdNi and PdNi clusters to adsorb H atoms is substantially higher than that of other clusters. The H desorption energies of PdNi and PdNi are also lower than that of the Pd cluster and comparable to that of the Ni cluster, indicating that it is easier to pull the H atom out of these bimetallic catalysts. This suggests that the catalytic efficiency for specific Pd Ni bimetallic clusters may be superior to bare Ni or Pd clusters and that it may be possible to tune bimetallic nanoparticles to obtain better catalytic performance.