Ignition Threshold of Perovskite-Based Oxides for Solid Fuel Oxidation from First-Principles Calculations

Solid oxidants are critical for solid fuel oxidation, such as in chemical looping combustion and solid rocket engines. By combining first-principles calculations, analytic modeling, and experiments on reactions between four types of perovskite-based oxides and aluminum, a prototype solid fuel, we have studied the ignition temperature and reaction kinetics of solid fuel oxidation. We find that oxygen vacancy formation energy serves as a critical parameter in determining the ignition reaction. Specifically, the ignition temperature of each type of structure increases monotonically, but nonlinearly, with the oxygen vacancy formation energy, and the reaction barrier of ignition exhibits structural dependence. Based on our analyses, we predict two materials, YBa₂Cu₃O₇ and WO₃, to exhibit low ignition temperature, which is confirmed by subsequent experiments. This study is expected to guide the rational search of new solid oxidants with desirable ignition temperature and ignition kinetics in the vast material space of oxides.