A Theoretical Study of the In Situ Structural Reconstruction of Pd<em>_n</em> (<em>n</em> = 6, 19, 44) Clusters for Catalytic Hydrogen Evolution

How in situ structural reconstructions affect the hydrogen evolution reaction (HER) activity of small Pd clusters is a long-standing problem in the field of heterogeneous catalysis. Herein, we reveal the structural evolution of Pdn (n = 6, 19, 44) clusters under the HER environment via stochastic global potential energy surface searching. We theoretically demonstrated that the HER activity of Pdn clusters first increases and then decreases under long-term working conditions. The intrinsic nature of these phenomenons includes interior H formations and structural reconstructions caused by the supersaturated adsorption of H atoms. This proves that carefully adjusting the hydrogenation degree of Pd clusters is a good strategy for improving the HER’s catalytic performance