Frustrated Lewis Pair-Mediated Pt/CeO2 for Sulfur-Tolerant Hydrogenation of Nitroaromatics

Abstract

Catalytic hydrogenation of sulfur-containing nitroaromatics represents a longstanding challenge due to the strong poisoning of metal sites by sulfur moieties. Conventional strategies to weaken metal–sulfur interactions typically compromise the adsorption/activation of both H2 and the nitro group, creating an intrinsic trade-off between sulfur tolerance and hydrogenation activity. Herein, we report a frustrated Lewis pair (FLP)-mediated Pt/CeO2 catalyst that overcomes this limitation by spatially decoupling substrate adsorption from H2 dissociation. The FLP sites, consisting of adjacent Lewis acidic Ce3+ centers and Lewis basic lattice oxygen derived from abundant surface oxygen vacancies on porous CeO2 nanorods, enable the selective adsorption of the −NO2 group of 4-nitrothioanisole via bidentate coordination, thereby circumventing the need for the nitro group to interact with sulfur-blocked Pt sites. With the assistance of *H species generated on Pt clusters and subsequent spillover, the Pt/CeO2–FLP catalyst achieves a turnover frequency of 4677 h–1 at 80 °C for 4-nitrothioanisole hydrogenation, substantially outperforming state-of-the-art catalysts. This work broadens the application scope of solid FLP chemistry in heterogeneous catalysis for fine chemical synthesis.