Interface charge modification–defect engineering–H2O-Mg2+ microenvironment synergistic catalysis for full-process kinetic optimization of MgH2 dehydrogenation

Abstract

Decoupling the multifaceted kinetic limitations in the dehydrogenation process of magnesium hydride (MgH 2 ) is crucial for its large-scale commercial application. This study proposes a synergistic catalysis strategy of “interface charge modification–defect engineering–H 2 O-Mg 2+ microenvironment”. In this strategy, the charge back-transfer effect induced by interface charge modification weakens the Mg-H bonds overall and promotes bulk hydrogen migration; defect engineering removes the hydrogen transport limitation of the catalyst; the reverse hydrogen spillover effect triggered by the H 2 O-Mg 2+ microenvironment significantly reduces the H 2 recombination and desorption energy barrier from 2.07 eV to 0.49 eV. This catalytic strategy systematically optimizes the H migration, interface transport, and surface reaction kinetics during the dehydrogenation process of MgH 2 , providing a generalizable theoretical strategy for the full-process kinetic optimization of metal hydride hydrogen storage materials.