Nb(V)-Containing Saponite Clay: a Catalyst for the Oxidative Abatement of Blistering Chemical Warfare Agents

The abatement of toxic chemical warfare agents (CWA) is conventionally achieved via stoichiometric reactions using strong oxidants with high environmental impact and/or via thermal degradation. In this work a class of heterogeneous catalysts is designed to transform selectively and under mild conditions toxic organosulfur chemical agents in non-noxious products with reduced environmental impact. Nb(V)-containing saponite clay was identified as an optimal catalyst for the CWA oxidative abatement. The conventional synthetic protocol used to obtain saponite materials was modified to allow the insertion of Nb(V) ions within the inorganic framework of the clay, thus obtaining a bi-functional catalyst with strong oxidizing and acid properties. The catalytic performance of these clays was evaluated in the oxidation reaction of (2-chloroethyl)ethylsulfide (CEES), simulant of sulfur mustard (blistering CWA), with aqueous hydrogen peroxide. Remarkable activity and outstanding selectivity were obtained, at room temperature and ambient pressure, with respect to a conventional commercial decontamination powder mixture.