Li Qiang1， Wang Yukun1，2， Wang Dengke1， Cui Qitong1， Wu ye2
Abstract
Significance RDX （hexahydro-1，3，5-trinitro-1，3，5-triazine） is a key high-energy component in solid propellants， and its thermal decomposition behavior directly determines crucial combustion performance parameters such as burning rate and pressure exponent. To achieve targeted improvements in the combustion performance of RDX-based solid propellants， regulating the thermal decomposition of RDX through catalysts has become a research focus. Over the past decades， significant progress has been made， evolving from initial catalyst screening to advanced studies on structural design， interface engineering， and in-depth mechanistic understanding. This review summarizes the influence of various catalysts on the kinetics， pathways， and performance outcomes of RDX thermal decomposition， highlighting the critical roles of nanoscaling， composite modification， interfacial interactions， and synergistic catalysis.
Progress This review systematically covers the research progress on four main categories of combustion catalysts for RDX thermal decomposition. 1） Metal and alloy catalysts： Early studies show that nano-Al significantly catalyzes RDX decomposition， lowering activation energy more effectively than micron-sized Al. Research elucidates that Al promotes C—N bond cleavage over the primary N—N bond rupture. Advanced experimental and simulation techniques further reveal the underlying mechanisms. First-principles and ReaxFF molecular dynamics simulations show that the interface bonding method （e.g.， core-shell Al@RDX vs. physical mixture Al+RDX） critically influences the reaction pathway， kinetics， and energy release. Furthermore， Al nanoparticles alter the pressure exponent of RDX decomposition by changing the initial decomposition pathway at low pressure， but the effects become saturated at high pressure. Studies on other metals like Mg and Pb single atoms， and alloys like Cu-Al and Sn-based intermetallics， confirm their catalytic efficacy through mechanisms involving strong adsorption， electron transfer， and synergistic effects. 2） Metal oxide catalysts： Metal oxides are highly effective catalysts. Research on single-component oxides like CuO， Fe2O3， and Cr2O3 shows that catalytic activity is not only composition-dependent but also strongly influenced by morphology， with nanorods exhibiting superior performance due to higher surface area. The formation of core-shell structures （e.g.， RDX@CuO） is shown to enhance catalytic contact. DFT calculations reveal that the crucial catalytic step often involves the adsorption and activation of the decomposition product NO2 on the oxide surface， with NO2 adsorption energy correlating with catalytic activity. Subsequently， binary metal oxides with spinel structures （e.g.， MCo2O4， CuFe2O4） and composite oxides （e.g.， Fe-doped CuBi2O4， CuFe2O4 or SiO2） are developed， demonstrating enhanced catalytic performance attributed to bimetallic synergy， increased oxygen vacancies， and improved dispersion on supports. 3） Carbon-based composite catalysts： Carbon materials like graphene oxide （GO）， graphitic carbon nitride （g-C3N4）， and carbon nanotubes （CNTs） serve as excellent support to disperse and stabilize catalytic nanoparticles. Studies on GO loaded with metal oxides （e.g.， Bi2WO6， MgFe2O4） and metal complexes confirm the effectiveness of the support. ReaxFF simulations elucidate a key hydrogen exchange cycle involving GO's oxygen-containing functional groups， which lowers energy barriers for RDX decomposition. Similarly， g-C3N4 and CNTs are shown to enhance the dispersion of active phases like CuFe2O4 or Fe2O3， and their high thermal conductivity facilitates heat transfer， collectively promoting RDX decomposition. Novel approaches also include encapsulating metal salts within CNTs and using porous activated carbon or bio-derived carbon as supports. 4） Metal complex catalysts： To mitigate the energy dilution caused by inert catalysts， energetic metal complexes have been developed. Energetic coordination polymers based on azoles （e.g.， tetrazoles， imidazoles）， nitro compounds， and azines are synthesized. Their catalytic action often involves in-situ generation of highly active metal oxides or synergistic effects from multinuclear metal clusters， as observed in ZIF-67 and bimetallic MOFs like CuFe-MOF and Mn-Co-MOF， which can alter the fundamental decomposition pathway of RDX. Inert metal-organic catalysts， such as lead citrate or 2，4-dihydroxybenzoate， can also be effective， sometimes by in-situ formation of active oxide nanoparticles. Nanothermite composites （e.g.， Al+MoO3， Al+Fe2O3） represent another class， where their catalytic effect involves solid-state redox reactions， electron transfer to RDX， and generation of active species， offering a multi-mechanism approach to enhance energy release and modulate performance.
Conclusions and Prospects Significant progress has been made in understanding the catalytic effects on RDX thermal decomposition. The field has progressed from simple material screening to sophisticated catalyst design and mechanistic elucidation at the molecular and atomic levels， utilizing advanced experimental techniques and theoretical simulations. Nanoscaling and composite modification have been confirmed as key strategies to enhance catalytic activity. Despite this progress， several challenges remain： 1） research is often confined to binary catalyst-RDX systems， lacking validation in complex propellant formulations； 2） scalable and reproducible preparation of advanced nanocatalysts is underdeveloped； 3） the understanding of catalyst evolution and active species under realistic combustion conditions is incomplete； and 4） a unified， in-depth evaluation system for catalyst performance is needed. Future research should prioritize studies in practical propellant formulations， develop scalable synthesis technologies， and deepen the fundamental understanding of catalytic mechanisms to fully exploit the potential of catalysts for next-generation high-energy solid propellants.
Keywords： solid propellant； RDX thermal decomposition； catalyst
Get Citation:Li Qiang， Wang Yukun， Wang Dengke， et al. Research progress on influence mechanism of combustion catalysts on thermal decomposition of RDX［J］. China Powder Science and Technology， 2026， 32（6）： 1-22.
Received：2026-03-16， Revised： 2026-06-01， Online： 2026-07-18。
Funding： The research was supported by the Major Project in the Field of Advanced Power Industry Infrastructure of the National Defense Science and Technology Industry Administration and the Inner Mongolia Natural Science Foundation Project (Grant No. 2021BS05014).
CLC No.:V512；TQ560.7；TB4
Type Code:A
Serial No.:1008-5548（2026）06-0001-22
