Layered Vanadium Oxides with Expanded Interlayer Spacing for Rapid Degradation of Mustard Gas Simulants

Abstract

The high toxicity of mustard gas and its severe threat to public safety have spurred efforts to develop catalysts for rapid degradation. Layered vanadium oxides are promising potential catalysts owing to their abundant and tunable active sites. Herein, via intercalation of [Ni(Hppz)3]2+ complexes (Hppz = 2-(1H-pyrazol-3-yl)pyridine), we synthesised a layered mixed-valence vanadium oxide, Na[Ni(C8N3H7)]3(V3IVV5VO20) (V8O20-Ni), featuring an interlayer spacing of 11.5 Å. The large interlayer spacing and wavy layer structures maximise active sites exposure, while mixed-valence V5+/V4+ centres facilitate efficient charge transfer during oxidation. To verify structure-activity relationships, [Ni(C8N3H7)](V2O6) (V2O6-Ni) and [Ni(C8N3H7)](V6O16) (V6O16-Ni) were synthesized as comparisons referenec. In the catalytic oxidation of the chemical warfare agent simulant 2‑chloroethyl ethyl sulfide (CEES), V8O20-Ni exhibited exceptional degradation performance with a short half‑life (t1/2 = 0.52 min), delivering a record turnover frequency (TOF) of 207 min-1. The catalyst also displays broad substrate compatibility and robust stability, maintaining superior activity after six cycles. This work establishes an interlayer-embedding strategy for constructing high-performance layered vanadium oxide catalysts applicable to selective oxidation reactions.