Enhanced hydrogen desorption property of MgH2 with the addition of cerium fluorides

• Activation energy of MgH2 desorption is remarkably reduced with the dopant of CeF4.
• The improvement might be attributed to new Ce–F–Mg species at the CeF4/MgH2 interface.
• Easy electron transfer induced from the high valence Ce-cation benefits MgH2 desorption.

Hydrogen desorption property of MgH2 doped with cerium fluorides with different valences prepared using ball milling has been studied. CeF4 is catalytically active for hydrogen desorption of MgH2. Hydrogen desorption temperature and apparent activation energy of MgH2 are significantly reduced with dopant of 2 mol% of CeF4, which might be attributed to the formation of a new Ce–F–Mg specie at the CeF4/MgH2 interface and the easy electron transfer induced from the high valence Ce-cation. The apparent activation energy of hydrogen desorption of MgH2 is reduced from ∼160 kJ/mol to ∼110 kJ/mol with the dopant of CeF4.