Experimental study on the ignition and combustion of Mg particles enhanced by metal oxides in CO2

Due to the high cost and long lifecycle of manned Mars exploration missions, in-situ resource utilization technology, including Mg/CO 2 processes, has attracted increasing attention. At present, Mg/CO 2 engines face the challenges of long ignition delay, serious carbon deposition, and low combustion efficiency. The root of these challenges lies in the Mg/CO 2 combustion reaction. Therefore, based on an Mg-based powder prepared by mechanical mixing combined with ultrasonic dispersion, the effects of various nano-metal oxides (CuO, Fe 2 O 3 , MnO 2 , MoO 3 , and Bi 2 O 3 ) on the ignition and combustion of Mg particles in CO 2 were studied through constant volume combustion experiments. It was found that MoO 3 undergoes the optimal covered-type of binding with Mg particles. The other oxides achieved embedded-type binding, of which MnO 2 binding was the worst. The enhanced ignition and combustion effects of Bi 2 O 3 and CuO were best. Thermogravimetric analysis found that CuO and Bi 2 O 3 improve combustion efficiency by lower ignition temperatures, inhibiting low-temperature oxidation reaction and increasing reaction ratio. • The enhancement effects of metal oxides on ignition and combustion of Mg particles in CO 2 are firstly studied. • The binding abilities of different nano-metal oxides to micro-Mg particles are analyzed. • The enhancement effects of CuO and Bi 2 O 3 on ignition and combustion of Mg particles in CO 2 are analyzed. • The influences of metal oxide addition ratio on enhancement are analyzed.