Adsorption and decomposition of dimethyl methylphosphonate on Y2O3 nanoparticles

Experimental studies explore the adsorption and decomposition pathways of the nerve agent simulant, dimethyl methylphosphonate (DMMP), on Y2O3 nanoparticles with mean diameters of 6 and 2 run. DMMP adsorption on Y203 was studied in an ultrahigh vacuum surface science instrument with X-ray photoelectron spectroscopy and reflection absorption infrared spectroscopy. Uptake probability measurements reveal an initial sticking probability near unity, while vibrational spectroscopy indicates that adsorbed DMMP dissociates via cleavage of a P-OCH3 bond to form a bridging O-P-O surface species. The extent of DMMP decomposition is found to increase as the particle size decreases, suggesting that edge, corner, and defect sites play a major role in the outcome of the gas-surface interaction.