Impact of CeO2 and GO on the combustion performance of HAN-based electrically controlled solid propellant

Electrically controlled solid propellant (ECSP) offers multiple ignition and adjustable burning rate, serving as fuel for next-generation intelligent propulsion systems. To further enhance the combustion performance of ECSP, a method utilizing electrochemical and thermal decomposition catalysts has been proposed. In this work, we investigated the combustion characteristics of hydroxylamine nitrate (HAN)-based ECSP incorporating cerium oxide (CeO2) and graphene oxide (GO) by using an electrically controlled combustion test system. Electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV) were used to measure the electrical conductibility and overpotential of ECSP with various additives, and Tafel curves were calculated. Thermogravimetric analysis coupled with differential scanning calorimetry (TG-DSC) was employed to investigate the thermal decomposition behavior of ECSP. While the addition of CeO2 and GO reduced the conductivity of ECSP, both catalysts exhibited strong electrocatalytic properties and facilitated the thermal decomposition of ECSP. Between two catalysts, GO demonstrated superior electrochemical catalytic performance but weaker thermal decomposition catalytic ability than CeO2. The addition of catalysts significantly enhanced the combustion performance of HAN-based ECSP. Specifically, the ignition delay time was shortened by 10%∼20%. CeO2 raised the burning rate by approximately 20% but GO exhibited a remarkable boost of 40% in burning rate at high voltage. The combination of GO and PVA produced a flame-retardant substance that negatively impacted the ignition delay of ECSP and resulted in a smaller increase in the burning rate of ECSP at low ignition voltages.