Copper isolated sites on MXene for efficiency aniline synthesis utilizing H2S as a hydrogen source

Abstract

Hydrogen sulfide (H₂S), a secondary energy carrier with remarkable energy density, has emerged as an innovative hydrogen donor for the hydrogenation of nitroarenes. Nevertheless, the lack of efficient catalysts has impeded the development of this novel resource utilization method. Here, we proposed a facile and eco-friendly approach for the synthesis of isolated Cu sites on MXene catalysts by a combination of Lewis acid salt melt etching and oxidative dispersion. The as-designed MXene catalysts demonstrate high activity and product selectivity towards different nitroarenes at 70 °C within a 2 h reaction. The in-situ characterizations and DFT calculations reveal that the active Cu sites significantly lower the energy barriers for the nitro dissociation and hydrogenation of intermediates, facilitating amino formation. The mechanism involves an acceleration of the hydrogen transfer process over C₆H₅NO₂*, leading to hydroxylation of the nitro group followed by deprotonation, ultimately resulting in the formation of an amino group.