A cobalt phosphide catalyst for the hydrogenation of nitriles

Abstract

<p>A well-defined nano-cobalt phosphide serves as an air-stable, highly active and reusable heterogeneous catalyst for the selective hydrogenation of nitriles to primary amines under mild reaction conditions.</p>

Single-Crystal Cobalt Phosphide Nanorods as a High-Performance Catalyst for Reductive Amination of Carbonyl Compounds

“…The Co 2 P NRs were synthesized according to a previously reported method with slight modifications (e.g., the metal precursor used). 22 Cobalt(II) acetylacetonate [Co(acac) 2 ] was added to 1-octadecene in the presence of hexadecylamine and triphenylphosphite. The mixture was stirred under an argon atmosphere, while the temperature was increased to 300 °C, which generated a black colloidal solution.…”

“… 16 − 20 Nevertheless, we recently reported the catalytic activity of nickel and cobalt phosphide nanoalloys for the transformation of biofuranic aldehydes to diketones and the hydrogenation of nitriles to primary amines, respectively, exhibiting turnover numbers (TONs) an order of magnitude higher than those of conventional non-noble-metal catalysts. 21 , 22 Based on the above studies, we concluded that “phosphorus-alloying (P-alloying)” has two important roles in non-noble-metal-catalyzed organic transformations. One is its ability to stabilize low valent metals.…”

“…This effect imparts the metal with a high ability to hydrogenate. 22 Furthermore, we envisaged that P-alloying could be advantageous for the creation of well-defined catalytically active species in the crystalline metal phosphide that favor selective reactions. This is in contrast to conventional heterogeneous catalysts, which have multiple ill-defined active sites that result in inferior catalytic performance.…”

Ni2P Nanoalloy as an Air‐Stable and Versatile Hydrogenation Catalyst in Water: P‐Alloying Strategy for Designing Smart Catalysts

“…In this context, our research group has recently focused on exploring novel catalysis by metal phosphide nanoalloys. We found that non‐noble metal phosphide nanoalloys, such as nickel and cobalt phosphides, retain their metal‐like states in air and exhibit high catalytic activity for the hydrogenation of biofuranic aldehydes to diketones [32] and of nitriles to amines [33] . On the basis of our studies, we envisaged that alloying non‐noble metals with phosphorus would have several merits in organic transformations.…”

“…The second is the modulation of the electronic state of the metal species (ligand effect). Density functional theory calculations revealed that P‐alloying can increase the d‐electron density of metals near the Fermi level, facilitating hydrogenation [33] . The third is the precise creation of a well‐defined catalytic active species in the metal phosphide nanocrystal, which favors selective reactions.…”