The oxygen vacancy defect induced by Ar plasma significantly reduces the initial reaction energy barrier of micron thermite and improves its combustion reaction efficiency

[Display omitted] •Defect engineering of thermite is firstly realized by Ar plasma surface treatment on transition metal oxidant.•Oxygen vacancy defects can enhance the REDOX reactivity of transition metal oxides.•The initial reaction activation energy of Al/MoO3 reduced by 29.8 % and the reaction heat release of Al/MoO3 increased by 56.7 %.•The presence of oxygen vacancy does not reduce the combustion temperature of thermite, and can significantly prolong the combustion flame duration of thermites. In order to reduce the initial reaction energy barrier and combustion reaction efficiency of micron thermite, this work firstly combined Ar plasma surface treatment technology and defect engineering strategy, and applied MoO3, Co3O4 and CuO containing oxygen vacancy to micron thermites to explore the effect of oxygen vacancy defect on the combustion reaction performance of thermites system. Taking the Al/MoO3 thermite system as an example, the results of thermal analysis and molecular dynamics simulation show that the presence of oxygen vacancy promotes the atomic migration of the thermite component atoms at the contact interface, thus reducing the initial reaction activation energy of Al/MoO3 by 29.8 % and increasing the reaction heat release by 56.7 %. This work expands the application of plasma in the field of energetic materials and provides a more efficient and safer method for their modification.