Pretreatment Effects on the Adsorption and Decomposition of Sarin Simulant Dimp on Titania and Ceria with Platinum Clusters

Since the introduction of chlorine gas in 1915, air filtration technologies have evolved dramatically, yet the fundamental adsorbent materials used in gas masks have remained largely unchanged for decades. Current protective systems rely on activated carbon filters such as ASZM-TEDA, which provide effective adsorption but limited catalytic degradation of chemical warfare agents (CWAs). To address this limitation, advanced materials are being investigated to enhance both adsorption and catalytic neutralization.

Among these, Metal-Organic Frameworks (MOFs), Covalent Organic Frameworks (COFs), and zeolites offer high surface area and tunable pore structures that can be leveraged for CWA mitigation. In parallel, transition metal oxides such as TiO₂, CuO, and Fe₂O₃, in this case coated with platinum nanoparticles, have demonstrated promise due to their acidic and basic active sites, redox flexibility, and ability to generate reactive oxygen species. In particular, cerium dioxide (CeO₂) stands out for its high oxygen storage capacity and ability to cycle between Ce³⁺ and Ce⁴⁺ states, enabling the transport of mobile oxygen species critical to organophosphate decomposition.

Building on prior studies involving platinum-modified titanium dioxide (Pt/TiO₂) for dimethyl methylphosphonate (DMMP) degradation, this work investigates platinum-supported cerium oxide (Pt/CeO₂) catalysts to understand how Pt oxidation states and pretreatment conditions affect DMMP and DIMP decomposition pathways. Through controlled surface modification, we aim to generate active oxygen species and elucidate the catalytic mechanisms that govern organophosphate breakdown. Preliminary results indicate that CeO₂ exhibits superior intrinsic activity compared to TiO₂, and strategic surface engineering with Pt can further enhance degradation efficiency.

This study contributes to the advancement of next-generation CWA filtration systems by integrating adsorption and catalytic degradation mechanisms. The insights gained from this work could guide the rational design of regenerative, high-efficiency filters capable of neutralizing a broad spectrum of toxic compounds.