Nanosized ZnIn2S4 supported on facet-engineered CeO2 nanorods for efficient gaseous elemental mercury immobilization.

Abstract The design and exploitation of high-performance catalysts have gained considerable attention in selective hydrogenation reactions, but remain a huge challenge. Herein, we report a RuNi single atom alloy (SAA) in which Ru single atoms are anchored onto Ni nanoparticle surface via Ru–Ni coordination accompanied with electron transfer from sub-surface Ni to Ru. The optimal catalyst 0.4% RuNi SAA exhibits simultaneously improved activity (TOF value: 4293 h –1 ) and chemoselectivity toward selective hydrogenation of 4-nitrostyrene to 4-aminostyrene (yield: &gt;99%), which is, to the best of our knowledge, the highest level compared with reported heterogeneous catalysts. In situ experiments and theoretical calculations reveal that the Ru–Ni interfacial sites as intrinsic active centers facilitate the preferential cleavage of N–O bond with a decreased energy barrier by 0.28 eV. In addition, the Ru–Ni synergistic catalysis promotes the formation of intermediates (C 8 H 7 NO* and C 8 H 7 NOH*) and accelerates the rate-determining step (hydrogenation of C 8 H 7 NOH*). 

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Highly-efficient RuNi single-atom alloy catalysts toward chemoselective hydrogenation of nitroarenes

Selective hydrogenation of alkynes to alkenes plays a crucial role in the synthesis of fine chemicals. However, how to achieve high selectivity and effective separation of the catalyst and substrate while obtaining high activity is the key for this reaction. In this work, a Pd single‐atom catalyst is anchored to the shell of magnetic core–shell particles that consist of a Ni‐nanoparticles core and a graphene sheets shell (Ni@G) for semi‐hydrogenation of phenylacetylene, delivering 93% selectivity to styrene at full conversion with a robust turnover frequency of 7074 h−1 under mild reaction conditions (303 K, 2 bar H2). Moreover, the catalyst can be recovered promptly from the liquid phase due to its magnetic separability, which makes it present good stability for enduring five cycles. Experimental and theoretical investigations reveal that H2 and substrates are activated by atomically dispersed Pd atoms and Ni@G hybrid support, respectively. The hydrogenation reaction occurs on the surface of Ni@G via hydrogen spillover from the metal to the support. Such a strategy opens an avenue for designing highly active, selective, and magnetically recyclable catalysts for selective hydrogenation in liquid reaction systems.

A Magnetically Separable Pd Single‐Atom Catalyst for Efficient Selective Hydrogenation of Phenylacetylene

Ru single atoms for efficient chemoselective hydrogenation of nitrobenzene to azoxybenzene

Transfer hydrogenation reactions using non-noble metal-based nanocatalysts are extensively attractive due to their low-cost and green reaction conditions. But construction of such catalysts with maximum metal atom efficiency and high catalytic activity is still a challenging research goal. Here, atomically dispersed Co catalysts with Co-N4 active sites were fabricated, which builds a bridge for transfer hydrogenation between nitroarenes and saturated N-heterocycles in aqueous solution. The TOF value of the transfer hydrogenation reaction is much higher than nanoparticle catalyst for this reaction. Density functional theory (DFT) calculations and control experiments reveal that the excellent performance origins from the Co-N4 sites, which combines the dehydrogenation of 1,2,3,4-tetrahydroquinoline with hydrogenation of nitrobenzene in one-pot. This work not only has an in-depth understanding of active sites but also shows a unique activity to the challenging, highly efficient, and green transfer hydrogenation reaction.

Atomically dispersed Co-N4 sites anchored on N-doped carbon for aqueous phase transfer hydrogenation between nitroarenes and saturated N-heterocycles

Pt/CeO2 catalysts with different support shapes and prereduction temperatures were prepared and tested in the liquid-phase hydrogenation of nitrobenzene. Detailed characterizations reveal that the ...

Highly Efficient Hydrogenation of Nitrobenzene to Aniline over Pt/CeO2 Catalysts: The Shape Effect of the Support and Key Role of Additional Ce3+ Sites

Dongyang Zhao

Papers

Highly Efficient Hydrogenation of Nitrobenzene to Aniline over Pt/CeO2 Catalysts: The Shape Effect of the Support and Key Role of Additional Ce3+ Sites