Rapid synthesis of MgCo2O4: Morphology control, defect modulation, activity enhancement and applications

Organic fuels are the main factors affecting the morphology, pore structure and catalytic active sites of metal oxides in solution combustion synthesis (SCS). However, due to the diversity of organic fuel struc-tures, the specific role of organic fuel types on SCS is questionable. In this work, we compared the effects of five organic fuels on the thermocatalytic active sites of graded porous MgCo2O4 nanomaterials. MgCo2O4 (CA-MCO) prepared with citric acid as fuel has the largest specific surface area and the richest pore structure with the largest number of active sites. And the porous CA-MCO exhibited the best catalytic properties that the THTD of AP decreased by 206.06 degrees C, the activation energy (Ea) decreased by 104.58 kJ center dot mol-1, and the reaction rate (k) increased by 2.49 s-1. A possible catalytic mechanism for the thermal decomposition of AP was also proposed based on TG-MS and Hall effect tests. Finally, CA-MCO was applied to AP/HTPB-based composite solid propellants (CSPs), and the results showed that the introduction of CA-MCO significantly shortened the ignition delay time of the CSPs (From 29 ms to 8 ms), indicating its potential application in the CSPs. (c) 2023 Published by Elsevier B.V.

Automated summary

Organic fuels have a significant impact on the morphology, pore structure, and catalytic active sites of metal oxides in solution combustion synthesis (SCS). A comparative study was conducted on the effects of five organic fuels on the thermocatalytic active sites of graded porous MgCo2O4 nanomaterials. Citric acid-fueled CA-MCO exhibited the largest specific surface area, richest pore structure, and the highest number of active sites. The porous CA-MCO demonstrated the best catalytic properties, leading to a decrease in the thermal decomposition temperature of ammonium perchlorate (AP) by 206.06 degrees C, a decrease in activation energy (Ea) by 104.58 kJ·mol-1, and an increase in reaction rate (k) by 2.49 s-1. Furthermore, CA-MCO was successfully applied in AP/HTPB-based composite solid propellants (CSPs), significantly reducing the ignition delay time from 29 ms to 8 ms.