Active and Regioselective Ru Single-Site Heterogeneous Catalysts for Alpha-Olefin Hydroformylation

Abstract

A heterogeneous ruthenium catalyst consisting of isolated single atoms and disordered clusters stabilized in a N-doped carbon matrix has been synthesized with very good activity and remarkable regioselectivity in the hydroformylation of 1-hexene. The role of the nitrogen heteroatoms has been probed essential to increase the catalyst stability and activity, enabling the stabilization of Ru­(II)–N sites according to X-ray photoelectron spectroscopy (XPS) and XANES. Intrinsic size-dependent activity of Ru species of different atomicity has been extracted, correlating the observed reaction rate and the particle size distribution determined by means of aberration-corrected high-angle annular dark-field scanning transmission electron microscopy, permitting the identification of single-atom sites as the most active ones. This catalyst appears as a promising alternative with respect to its heterogeneous counterparts, paving the way for designing improved Ru heterogeneous catalysts.

Bifunctional atomically dispersed ruthenium electrocatalysts for efficient bipolar membrane water electrolysis

“…S2a, ESI†), indicating that Ru in Ru (0.2)-NC carries positive charges with an oxidation state of Ru δ + (0 < δ < 2). This was also confirmed by X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy measurements of the same sample in a recent work, 32 where the average formal oxidation state of Ru in Ru (0.2)-NC was found to be +1.2 and the mean coordination number of Ru with N is about 4. In addition, the high-resolution O1s spectra of pristine NC and Ru (0.2)-NC were also compared.…”

“…A RuN 4 model was used for the computation, considering the atomic structure of Ru (0.2)-NC confirmed by EXAFS. 32 Fig. 4a shows the adsorption configurations of the reaction intermediates on the pyrrole-type Ru (0.2)-NC model catalysts during the OER, which involves successive electron transfer steps with the related oxygenated intermediates of OH*, O* and OOH*.…”

A Career in Catalysis: Avelino Corma

“…For instance, Ru(II)−N species stabilized in a carbon matrix have been prepared with outstanding activity for the hydroformylation of 1-hexene compared to state of the art heterogeneous Ru-based catalysts. 408 The stabilization of isolated Ru sites and the local environment of Ru atoms has been shown critical for the remarkable catalytic performance, as revealed by the combination of spectroscopy (X-ray absorption spectroscopy (XAS) and XPS) and electron microscopy analysis. In addition, Pd and Ru metal nanoparticles have been obtained by controlled hydrothermal synthesis conditions, whose morphology and electronic properties are modulated by the incorporation of carbon atoms into the metal structure.…”

“…Considering the widely existing metal–C, metal–N, metal–P, and metal–S coordination interactions in enzymes, the role of C, N, P, and S ligands on the electronic properties of well-defined metal sites in solid catalysts has been explored. For instance, Ru­(II)–N species stabilized in a carbon matrix have been prepared with outstanding activity for the hydroformylation of 1-hexene compared to state of the art heterogeneous Ru-based catalysts . The stabilization of isolated Ru sites and the local environment of Ru atoms has been shown critical for the remarkable catalytic performance, as revealed by the combination of spectroscopy (X-ray absorption spectroscopy (XAS) and XPS) and electron microscopy analysis.…”

Core–shell Co@CoO catalysts for the hydroformylation of olefins

“…Hydroformylation of alkenes to aldehydes is known as the oxo process, which is a reaction wherein CO and H 2 are added across a carbon-carbon double bond and provides 100% atom economy from olefins to aldehydes. [1][2][3][4][5] The resulting aldehydes are easily converted into esters, alcohols, carboxylic acids, and aliphatic amines, which are widely used for the synthesis of plastics, structural units in fiber production and fine chemical intermediates. [6][7][8][9] In the chemical industry, Rh-based and Co-based homogeneous catalysts have been applied for the olefin hydroformylation process.…”