Lewis and Brønsted Acid Synergistic Catalysis for Efficient Synthesis of Hydroxylamine over Heteroatom Zeolites

Environmental and efficient synthesis of NH2OH is challenging. Herein, we have provided a route for efficient NH2OH formation by NH3 oxidation via the synergistic catalysis of Lewis acid sites of the framework Ti (Ti LAS) and Br & oslash;nsted acid sites of the framework Al (Al BAS) in Ti-Al-MOR zeolites. Ti LAS was the active center for formation of transition-state NH2OH, while Al BAS could provide the proton H to convert transition-state NH2OH absorbed on Ti LAS to a [NH3OH](+) species. Protonation effect would not only promote the catalytic cycle process resulting from accelerating the desorption of transition-state NH2OH, but also improve the stability of NH2OH, being less prone to oxidative decomposition. In this work, we presented the synergistic catalysis between LAS and BAS over Ti-containing heteroatom zeolites to accelerate the catalytic cycle, which provided an environmental and efficient method for NH2OH formation.