Hydrogen Generation from Water Splitting by 3H2O + Pd13 → 3H2 + Pd13O3 Reaction

The Pd clusters are widely concerned because of their outstanding catalytic capacity. Here such a candidate of Pd13 cluster with the icosahedron symmetry and multiple active sites is shown. The first‐principles calculations reveal that this cluster can maximally catalyze the water‐splitting reaction to generate three H2 from three H2O molecules. The geometrical structures of the reactants, transition states, and products are optimized, and their stabilities are confirmed by the frequency analysis. The intrinsic reaction coordinates are constructed to confirm the rationality of the reaction. Firstly, one H2O is adsorbed on atop sites of the Pd13 cluster and releases an H2 through a reaction of H2O@Pd13 → H2@[O+Pd13]. Then, the remained O+Pd13 cluster can continually split H2O and generate additional H2, and the obtained 2O+Pd13 cluster can also dissociate H2O to generate H2. However, it is found that the 3O+Pd13 cluster cannot continue the splitting reaction. It is also observed that the O+Pd13 cluster can adsorb two molecules at the same time and split them one by one. These findings support that the Pd13 cluster, O+Pd13, and 2O+Pd13 are promising candidates for efficient generation of H2 from H2O splitting reaction. The possibility that the cluster Pd13 can maximize the catalytic decomposition of water by successively decomposing three H2O molecules to form three H2 molecules is investigated, and the endogenous reaction coordinates of the water decomposition reaction on the potential energy surface are used to confirm the pathway by which the reaction occurs.