Formation and nitrile hydrogenation performance of Ru nanoparticles on a K-doped Al₂O₃ surface

Abstract

Decarbonylation-promoted Ru nanoparticle formation from Ru3(CO)12 on a basic K-doped Al2O3 surface was investigated by in situ FT-IR and in situ XAFS. Supported Ru3(CO)12 clusters on K-doped Al2O3 were converted stepwise to Ru nanoparticles, which catalyzed the selective hydrogenation of nitriles to the corresponding primary amines via initial decarbonylation, the nucleation of the Ru cluster core, and the growth of metallic Ru nanoparticles on the surface. As a result, small Ru nanoparticles, with an average diameter of less than 2 nm, were formed on the support and acted as efficient catalysts for nitrile hydrogenation at 343 K under hydrogen at atmospheric pressure. The structure and catalytic performance of Ru catalysts depended strongly on the type of oxide support, and the K-doped Al2O3 support acted as a good oxide for the selective nitrile hydrogenation without basic additives like ammonia. The activation of nitriles on the modelled Ru catalyst was also investigated by DFT calculations, and the adsorption structure of a nitrene-like intermediate, which was favourable for high primary amine selectivity, was the most stable structure on Ru compared with other intermediate structures.

Hydrotalcite-Supported Cobalt Phosphide Nanorods as a Highly Active and Reusable Heterogeneous Catalyst for Ammonia-Free Selective Hydrogenation of Nitriles to Primary Amines

“…Other oxide supports, such as Al 2 O 3 and SiO 2 , were also effective in providing 2a in moderate-to-high yields (entries 5 and 6), whereas carbon and hydroxyapatite (HAP) resulted in lower yields of 2a (entries 7 and 8). These results demonstrate that the type of support affects the hydrogenation efficiency, which implies the importance of the interaction between Co 2 P NR and the support for nitrile hydrogenation …”

“…These results demonstrate that the type of support affects the hydrogenation efficiency, which implies the importance of the interaction between Co 2 P NR and the support for nitrile hydrogenation. 38 With the Co 2 P NR/HT catalyst in hand, the substrate scope was explored by studying the hydrogenation of a series of aliphatic and (hetero)aromatic substrates (Table 2). Regarding the aliphatic nitriles (entries 1−4), 1a and decanenitrile (1b) underwent hydrogenation smoothly to produce the corresponding primary aliphatic amines in 93 and 87% yields, respectively (entries 1 and 2).…”

Selective Heterogeneous Catalytic Hydrogenation of Nitriles to Primary Amines

“…Ruthenium can also be used for the heterogeneous catalytic hydrogenation of nitriles in supported form [65][66][67] or as nanoparticles [68].…”

“…In 2015, Muratsugu et al [67] reported a decarbonylation-promoted Ru nanoparticles formation from Ru 3 (CO) 12 precursor, wich were dispersed on a basic K-doped Al 2 O 3 support surface. This catalyst was active and selective for the hydrogenation of nitriles to the appropriate primary amines without using any basic additives (e.g.…”

Chemoselective hydrogenation of nitriles to secondary or tertiary amines catalyzed by aqueous‐phase catalysts supported on hexagonal mesoporous silica

“…These achievements were reached by the judicious control of various parameters, depending on the structure of the nitriles, including the nature of the catalyst and its support, and the reaction conditions employed such as reaction temperature, solvent used and hydrogen pressure . Thus, primary amines have been selectively prepared in good to excellent yields, under mild conditions, with various supported catalysts, namely Co/SiO 2 , Co(OAc) 2 /1,10‐phenanthroline/α‐Al 2 O 3 , Ru nanoparticles/K‐doped Al 2 O 3 , Cu/MgO, vitamin B 12 ‐derived Co/CeO 2 , Pd/Al 2 O 3 and Pd/MCM‐41 . Heterogeneous processes concerning highly selective nitrile hydrogenation to secondary or tertiary amines have been also abundantly investigated.…”