Origins of the hydrogen spillover effect in d-block metals

(M = Ru, Mn, Fe, Co, or Ni) as a representative case by combining spectroscopic quantification and computational investigation, the nonlinear spillover capability and rate of d-block metal originates from the synergistic overlap of its unoccupied d-s orbitals, and the σ and σ* orbitals of the H atom equivalents interact to form a weak antibonding state, reducing the dissociation of the H-H bond and M-H bond. This methodology provides a refined lens for dissecting spillover mechanisms, facilitating a profound mechanistic and spatial understanding of rational metal dilution.