Electron-rich Pt anchored on covalent triazine frameworks for the selective hydrogenation of halogenated nitrobenzenes

Abstract

Halogenated nitroarenes’ hydrogenation on metal-based catalysts without dehalogenation to synthesize halogenated amines is a research challenge. Herein, using a covalent organic framework (COF) as a support and benefiting from strong metal–support interactions (SMSIs), ultrafine Pt nanoparticles were successfully anchored on a polyimide-based covalent triazine framework, to construct an electron-rich Pt active site-based catalyst (Pt/TAPT-COF). The electronic regulation from the COF contributed to both the selective hydrogenation of halogenated nitrobenzenes and the tandem hydrogenation-coupling reaction of halogenated nitrobenzenes with aldehyde compounds to synthesize halogenated amines with high selectivity under mild reaction conditions. According to density functional theory calculations, the hydrogenation of halogenated nitrobenzene is exothermic with strengthened absorption, confirming the existence of SMSIs to explain the high activity of Pt/TAPT-COF in hydrogenation reactions. Thus, this work provides a facile strategy to fabricate an electron-rich Pt-based catalyst enabled by SMSIs to selectively catalyze the synthesis of halogenated anilines and halogenated secondary amines.