Experimental Study of the Adsorption and Decomposition of Sarin on Dry Copper(II) Oxide

Organophosphonates were originally developed as insecticides but were quickly identified as highly toxic acetylcholinesterase inhibitors, leading to their exploitation as chemical warfare agents (CWA). To develop next generation filtration technologies, there must be a fundamental understanding of the molecular interactions occurring with toxic chemicals, such as CWAs. In this paper, we investigate the interaction between dry CuO nanoparticles and sarin (GB), using infrared (IR) spectroscopy in an effort to build an atomic understanding. We show sarin strongly interacts with CuO and then quickly degrades, primarily through the cleavage of the P-F bond, creating a bridging species on the CuO surface with the assistance of lattice oxygen. Upon heating, the decomposition product isopropyl methyl phosphonic acid (IMPA) does not continue to decompose but desorbs from the surface. These observations are further elaborated through theoretical models of sarin on dry CuO (111).