Effect of acid and base sites on the degradation of sulfur mustard over several typical oxides

The reactions of the chemical warfare agent sulfur mustard (HD) degradation over CaO, MgO, SiO2, Al2O3, HZSM-5, A-Clays were studied. More than 10 kinds of products from the degradation of HD over these oxides were detected and identified by GC-FPD, GC–MS, NMR and UV–vis approaches. All the studied oxides can exhibit reactivity towards destroying HD molecules in air at room temperature. The acid and base sites over the oxides were not entirely poisoned by H2O and CO2 in air as evidenced by the acid–base property characterization results. The conserved acid and base sites over the oxides might be the reaction center for degradation of HD molecules. Both degradation activity and product distribution were strongly determined by the strength and density of the acid–base sites and the adsorbed water over the oxides.