Regulation of the Properties of Hydrogen Dissociation and Transfer in the Presence of S Atoms for Efficient Hydrogenations

Abstract

The dissociation and spillover process of hydrogen is one of the key processes in hydrogenation reactions, but this process is very challenging or even impossible in the presence of a S atom, as S atoms can severely poison the surface of supported metal catalysts. Herein, we report that the efficient dissociation and transfer of hydrogen can be achieved in the presence of S poisoning over the synergetic process of hydrogen transfer units together with H₂ dissociation units in the hydrogenation of 5-nitrobenzothiazole catalyzed by Pt/MoO₃. Pt/MoO₃ showcases 99% conversion with ∼99% selectivity under mild reaction conditions and is one of the most active catalysts reported so far for the hydrogenation of sulfur atom-containing compounds. Mechanism studies, in situ characterization, and density functional theory calculations collectively demonstrate that the MoO₃ support, with H_1.68MoO₃ as an intermediate, acts as a bridge for transferring H species between Pt sites and nitrobenzothiazole. The unique H proton storage and release properties of in situ formed H_1.68MoO₃ not only accelerate the breaking of the N–O bond for the hydrogenation of 5-nitrobenzothiazole but also prevent sulfur poisoning. This work provides a promising strategy to tackle the current challenges in the catalytic hydrogenation of sulfur atom-containing compounds.