Green Synthesis of Rhodium Nanoparticles that are Catalytically Active in Benzene Hydrogenation and 1‐Hexene Hydroformylation

Abstract

Rhodium nanoparticles (Rh NPs) were prepared according to a green method based on the reduction of (acetylacetonato)dicarbonylrhodium(I), Rh(acac)(CO)2, in water at 80 °C. The nanoparticles, which were obtained without the addition of a reducing agent, were stabilized by polyvinylpyrrolidone (PVP) or polyvinyl alcohol (PVA) polymers and characterized by TEM (transmission electron microscopy), XPS (X‐ray photoelectron spectroscopy), and XRD (X‐ray powder diffraction) methods. The excellent catalytic activity of these Rh NPs was evidenced in the hydrogenation of benzene to cyclohexane. In the presence of PPh3, Rh NPs formed a highly active system in the hydroformylation of 1‐hexene. In this system, they acted as a source of soluble rhodium species. Rh NPs were also synthesized in water using rhodium(II) acetate, Rh2(OAc)4, and rhodium(III) chloride, RhCl3, as rhodium sources, and their catalytic activity was compared with that of the rhodium precursors.

Oxidative Alkenylation of Arenes Using Supported Rh Materials: Evidence that Active Catalysts are Formed by Rh Leaching

“…Dihydrogen chemisorption of the Rh/SiO 2 material indicated a metal dispersion of ∼0.7 (H/Rh ratio), and the average metal particle size measured by TEM was found to be 2.2(5) nm (Figure 1, Table S1). The presence of metallic Rh(0) was confirmed with XPS, which showed a binding energy at 307.3 eV (Figure S1) [37,52,53] …”

“…The presence of metallic Rh(0) was confirmed with XPS, which showed a binding energy at 307.3 eV ( Figure S1). [37,52,53] Nitrogen-doped carbon (NC) has been used as a support for single-atom catalysts with transition metals such as Co, [54][55][56] Mn, [54] Ni, [54] Fe, [54] Rh, [57] and Pd. [58] Supported Rh on nitrogendoped carbon (Rh/NC-HCl and Rh/NC-IWI) were prepared using a modified high-temperature thermal treatment as discussed in detail in the experimental section.…”

Reactive Ionic Liquid Enables the Construction of 3D Rh Particles with Nanowire Subunits for Electrocatalytic Nitrogen Reduction

“…As shown in Figure f, the Rh 3d signal exhibited two main peaks located at 307.45 eV and 312.27 eV, corresponding to 3d 5/2 and 3d 3/2 of metallic Rh, respectively . The peaks at 308.54 and 313.8 eV were corresponding to 3d 5/2 and 3d 3/2 of Rh 3+ . The little amount of oxidation state (Rh 3+ ) could be attributed to the partly oxidation of metallic Rh by the oxygen in the air.…”

“…[23] The peaks at 308.54 and 313.8 eV were corresponding to 3d 5/2 and 3d 3/2 of Rh 3 + . [24] The little amount of oxidation state (Rh 3 + ) could be attributed to the partly oxidation of metallic Rh by the oxygen in the air.…”

Reusable Catalysts for Hydroformylation‐Based Reactions

“…Trzeciak et al [78] described a sustainable approach for preparation of rhodium nanoparticles, through reduction of dicarbonyl rhodium(I) acetylacetonate. The nanoparticles were stabilized with polvinylpyrrolidone or polyvinylalcohol.…”