A 13C and 15N Solid State NMR Study of the Reactions of Acetone Oxime Adsorbed on FeZSM-5

Abstract

The reactions of acetone oxime, a proposed reaction intermediate for the SCR (Selective Catalytic Reduction) of NO with propane on FeZSM-5, have been studied with 13C and 15N solid state MAS NMR (magic angle spinning nuclear magnetic resonance). FeZSM-5 with three different loading levels was prepared by the sublimation method. The thermal reactions of acetone [2-13C] oxime adsorbed on FeZSM-5 samples with different iron loadings were monitored by 13C MAS NMR by heating to the desired temperature and then cooling to room temperature for data acquisition. For the sample with the lowest iron loading (Fe/Al = 0.11), acetic acid and N-methyl-2-propanamine were formed by the decomposition of acetone oxime. For the samples with the higher iron loadings (Fe/Al = 0.69 and 0.91), acetone, N,N′-methyl-2,2-propanediamine, and N-methyl-2-propanimine were formed by the decomposition of acetone oxime. 15N MAS NMR was used to investigate reactions of 15NO and acetone oxime on the FeZSM-5 samples. The formation of gas phase N2 and N2O was observed.