Green Synthesis of 2-Nitropropane via Ammoximation-Oxidation over Organic Base Modified TS-1 Catalysts

Graphical The hierarchical TS-1 with abundant mesopores was prepared by TPAOH/TIPA treatment, which was applied to the reaction of the ammoximation-oxidation of acetone to 2-nitropropane. Hierarchical TS-1 catalyst performed excellent reusability and catalytic activity with 97.5 % conversion and 96.8 % selectivity. The novel technology for clean and mild synthesis of nitroalkanes has been developed. Modified TS-1 catalysts for the acetone ammoximation-oxidation reaction were prepared by post-treating TS-1 with different concentrations of TPAOH/TIPA, and the effects of alkali treatment on the catalytic performance were systematically investigated. The techniques such as XRD, SEM, TEM and N 2 sorption were used to characterize the catalyst samples, which exhibited that the introduction of alkali increased the volume and quantity of mesopores, while there was no obvious influence on the framework structure and titanium content in the framework. And the improvement in catalyst performance after alkali treatment was attributed to the increase of mesopores and the decrease in diffusion limitation. In addition, three common ammoximation catalysts (Ti-MOR, Ti- MWW and TS-1) were systematically investigated in this reaction. Ti-MOR showed superiority in the ammoximation to oxime, while TS-1 displayed the best catalytic performance in the ammoximation oxidation of ketones to nitroalkanes. It was indicated that modified TS-1 could be a promising catalyst for the ammoximation-oxidation reaction of acetone.