Adsorption and decomposition of 2-chloroethylethylsulfide (CEES) on expanded graphite/metal oxides composites

Composites based on expanded graphite (EG) and metal oxides (MOs) were prepared by an explosive combustion and blending method. A metal oxide (Ag₂O, CuO or ZnO)-containing phase was employed as a component with reactive functionality, which was supported on EG as a component with adsorptive functionality. The reaction products of the adsorptive degradation of 2-chloroethylethylsulfide (CEES), a simulant of the well-known chemical warfare agent sulfur mustard (HD), were characterized by solid-state and solution NMR techniques. The elimination and hydrolysis reactions in the decontamination of CEES were shown to occur catalytically over the EG/Ag₂O composite. The molecular adsorption products of OCu· · ·SC₄H₉Cl surface complexes and OZnO–CH₂CH₂SC₂H₅ surface-bound alkoxy species contributed to the decontamination of CEES on the surface of the EG/CuO and EG/ZnO composites, respectively. All reaction products exhibited a lower toxicity than CEES, meaning that the EG/MO composites exhibited self-detoxifying properties.