Dense, Three-Dimensional, Highly Absorbent, Graphene Oxide Aerogel Coating on ZnCo2O4/ZnO Particles Exerts a Synergistic Catalytic Effect for Ammonium Perchlorate Thermal Decomposition.

As a new type of carbon material, graphene oxide aerogel (GA) is widely used in catalysis due to its porous structure, high-efficiency adsorption, and superb conductivity. In this study, GA was prepared into a dense coating layer surrounding ZnCo2O4/ZnO particles to form a composite GA-ZnCo2O4/ZnO by means of a hydrothermal, blast drying, and vacuum-freeze-drying approach applied to catalyze the thermal decomposition of ammonium perchlorate (AP). The physicochemical properties of the obtained GA-ZnCo2O4/ZnO were characterized by different analytical methods. Scanning electron microscopy (SEM) analysis exhibited that GA is coated on the surface of ZnCo2O4/ZnO, forming a dense layer. Brunner Emmet Teller (BET) measurement results show that GA-ZnCo2O4/ZnO has a smooth macropore distribution curve and a larger specific surface area. Moreover, The catalytic effect investigation on AP with GA-ZnCo2O4/ZnO: the high temperature decomposition (HTD) peak temperature of AP in the presence of 5 wt % GA-ZnCo2O4/ZnO was reduced from 441 to 294 °C, and the exotherm of AP was expanded from 205 to 1275 J/g at a heating rate of 15 °C/min. Through the calculation, GA-ZnCo2O4/ZnO makes the activation energy and Gibbs free energy of the AP pyrolysis lower so that the reaction is easier to occur. Thermogravimetric-mass (TG-MS) spectrometry revealed that during thermal decomposition of AP, GA-ZnCo2O4/ZnO leveraged the synergistic catalysis of ZnCo2O4/ZnO and GA that boosted the flow of electrons from ClO4- to O2 and increased the absorption of the gas product to accelerate the AP pyrolysis. These results provided a facile strategy to prepare GA-based composite catalysts with extraordinary application prospects in the domain of solid propellants.