Bronsted Acidic Catalysts Based on the Porous Aromatic Framework for Effective Oxidative Denitrogenation
A. V. Akopyan, Л. А. Куликов, M. A. Bazhenova, Nina V. Arzyaeva, A. L. Maximov, Э. А. Караханов
Abstract
Heterogeneous catalysts with Bronsted acid sites based on the porous aromatic framework (PAF) were applied for the oxidative denitrogenation process. Sulfonic groups immobilized on the PAF-20 support can form active peracid in the presence of hydrogen peroxide and on the other hand can efficiently coordinate both nitrogen- and sulfur-containing compounds, which are Lewis bases. This approach allows us to obtain efficient catalysts for oxidation of various types of nitrogen-containing compounds as well as sulfur-containing compounds and their mixtures. The main factors affecting the process consisting of the sulfonic group content, catalyst dosage, temperature, hydrogen peroxide amount, as well as concentration were investigated in detail. In the presence of the most active catalyst PAF-SO 3 H 500 under optimal reaction conditions, relatively inert carbazole was removed by 95% in just 10 min. Sulfonic groups are strong bonded to support which allows us to prevent their leaching and retain catalyst activity up to five cycles of oxidation regeneration.