Thermocatalytic decomposition is an efficient purification technology that is potentially applicable to degrading chemical warfare agents and industrial toxic gases. In particular, ZrO₂ has attracted attention as a catalyst for the thermocatalytic decomposition of dimethyl methylphosphonate (DMMP), which is a simulant of the nerve gas sarin. However, the influence of the crystal phase and morphology on the catalytic performance of ZrO₂ requires further exploration. In this study, monoclinic- and tetragonal-phase ZrO₂ (m- and t-ZrO₂, respectively) with nanoparticle, flower-like shape and hollow microsphere morphologies were prepared via hydrothermal and solvothermal methods, and their thermocatalytic decomposition of DMMP was systematically investigated. For a given morphology, m-ZrO₂ performed better than t-ZrO₂. For a given crystalline phase, the morphology of hollow microspheres resulted in the longest protection time. The exhaust gases generated by the thermocatalytic decomposition of DMMP mainly comprised H₂, CO₂, H₂O and CH₃OH, and the by-products were phosphorus oxide species. Thus, the deactivation of ZrO₂ was attributed to the deposition of these phosphorous oxide species on the catalyst surface. These results are expected to help guide the development of catalysts for the safe disposal of chemical warfare agents.

Here, we report a highly efficient and stable catalytic system based on monometallic oxides supported on HY zeolites for the catalytic oxidation of chlorobenzene (CB). Among the transition and rare-earth metal oxides screened, the 30Cu/HY catalyst demonstrates exceptional performance, achieving near 100% CB conversion at 300 °C (500 ppm CB, 10,000 h⁻¹) alongside outstanding 24 h continuous stability without deactivation. Quantitative Py-IR analysis reveals that this superior activity is fundamentally driven by extensive solid-state ion exchange, forming robust Lewis acid centers (Cu-Y structures) that synergize with zeolitic Brønsted acid sites to efficiently polarize and cleave C-Cl bonds. Through an integrated approach combining in situ DRIFTS, real-time mass spectrometry, TGA, and NLDFT pore size analysis, we elucidate that the exceptional deep-oxidation capability of Cu/HY continuously mineralizes carbonaceous intermediates. This property minimizes coke deposition (2.91 wt%) and preserves the hierarchical pore architecture, preventing the coverage of active sites and severe pore blockage by partially oxidized intermediates (such as phenolic, aldehydic, and quinonic species) and stable carbonate species responsible for the deactivation of other metal oxides. These insights provide a mechanistic framework for the rational design of robust, chlorine-resistant catalysts for the sustainable abatement of persistent organic pollutants.

Nerve agents, a highly toxic class of chemical warfare agents, pose serious risks to human health and social stability. Metal oxides are commonly used as catalysts to break down these agents through thermocatalytic decomposition. In particular, bimetallic oxide catalysts offer enhanced stability and catalytic efficiency due to their synergistic effects. In this study, CuO/ZrO₂ composite catalysts with varying Cu/Zr ratios were synthesized using a secondary hydrothermal method, resulting in a hollow microsphere morphology. The catalytic efficiency of these composites in thermocatalytically decomposing dimethyl methylphosphonate (DMMP), a sarin simulant, was systematically evaluated. The findings revealed that the catalyst with a 10%Cu/Zr ratio exhibited the best performance, achieving the longest protection duration of 272 min. The hollow microsphere structure facilitated high dispersion of CuO on the ZrO₂ surface, promoting strong interactions and generation of oxygen vacancies, which enhanced the catalytic activity. Furthermore, the catalytic reaction mechanism was explored by analyzing the surface characteristics of the catalyst and the resulting reaction products. This research addresses a gap in the application of CuO/ZrO₂ catalysts for DMMP decomposition and provides valuable insights for the future development of catalysts for chemical warfare agent degradation.