Silica-supported Fe/Fe\u2013O nanoparticles for the catalytic hydrogenation of nitriles to amines in the presence of aluminium additives

Vishwas G Chandrashekhar,Rajenahally V Jagadeesh,Matthias Beller,Ravishankar G Kadam,Radek Zbořil,Manoj B Gawande,Josef Kašlík,Thirusangumurugan Senthamarai,Ondřej Malina

doi:10.1038/s41929-021-00722-x

Abstract

The hydrogenation of nitriles to amines represents an important and frequently used industrial process due to the broad applicability of the resulting products in chemistry and life sciences. Despite the existing portfolio of catalysts reported for the hydrogenation of nitriles, the development of iron-based heterogeneous catalysts for this process is still a challenge. Here, we show that the impregnation and pyrolysis of iron(II) acetate on commercial silica produces a reusable Fe/Fe–O@SiO2 catalyst with a well-defined structure comprising the fayalite phase at the Si–Fe interface and α-Fe nanoparticles, covered by an ultrathin amorphous iron(III) oxide layer, growing from the silica matrix. These Fe/Fe–O core–shell nanoparticles, in the presence of catalytic amounts of aluminium additives, promote the hydrogenation of all kinds of nitriles, including structurally challenging and functionally diverse aromatic, heterocyclic, aliphatic and fatty nitriles, to produce primary amines under scalable and industrially viable conditions.

Highlights

Catalysis plays a decisive role in many basic and applied chemical processes and is involved in the industrial production of more than 90% of fine and bulk chemicals as well as polymeric materials and many other everyday products[1,2,3,4,5]
We report a stable and convenient iron-based nanocatalyst obtained by the pyrolysis of iron acetate on commercial silica that shows excellent activity and selectivity for the hydrogenation of a large number of nitriles to produce primary amines in the presence of catalytic amounts of aluminium additives
The excellent catalytic performance of carbon-encapsulated core–shell 3d metal nanoparticles has been demonstrated in a variety of hydrogenation reactions[14,16,17,22,39,40,46]

Summary

Introduction

Catalysis plays a decisive role in many basic and applied chemical processes and is involved in the industrial production of more than 90% of fine and bulk chemicals as well as polymeric materials and many other everyday products[1,2,3,4,5]. The success of organic synthesis in the last 100 years relied to a large extent on the discovery and application of suitable catalysts[1,2,3,4,5] In this respect, the development of practical and cost-efficient hydrogenation strategies constitutes a key achievement of the last century[6]. A plethora of molecularly defined metal complexes as well as heterogeneous materials are frequently applied for the selective hydrogenation of alkynes[7,8], olefins[7,9,10], carbonyl compounds[11,12], nitroarenes[13,14] as well as (hetero)arenes[7,15,16,17]. We report a stable and convenient iron-based nanocatalyst obtained by the pyrolysis of iron acetate on commercial silica that shows excellent activity and selectivity for the hydrogenation of a large number of nitriles to produce primary amines in the presence of catalytic amounts of aluminium additives

Methods

Results

Conclusion