Lighter Hydrogenation Catalysts Enzymes have evolved to use abundant metals such as iron, cobalt, and nickel for redox catalysis. However, synthetic catalysis has generally relied on the rarer, heavier relatives of these elements: ruthenium, rhodium, iridium, palladium, platinum (see Perspective by Bullock ). Friedfeld et al. (p. 1076 ) used high-throughput screening show that right cobalt precursor can be activated asymmetric hydrogenation using traditional ligands developed precious...

A MOF sets the stage to make amines Reductive amination is a common method that chemists use carbon-nitrogen bonds. The reaction, which often requires precious metal catalysts, couples ammonia or other with carbonyl compounds and then hydrogen. Jagadeesh et al. report class of nonprecious cobalt nanoparticles catalyze this reaction across very broad range substrates, including complex molecules pharmaceutical interest (see Perspective by Chen Xu). was first embedded in metal-organic...

X-ray photoelectron spectroscopy (XPS) investigations of supported nanoparticles smaller than 10 nm show a significant shift the electron binding energy core levels compared with bulk values. In this work, such shifts were examined at differently and prepared gold for 4f level. Special attention was paid to influence reducing pretreatment in hydrogen and, moreover, different oxide supports. Surprisingly, most cases, lower energies Au 4f7/2of 84.0 eV observed depending on oxidic support as...

Novel cobalt-based heterogeneous catalysts have been developed for the direct oxidative esterification of alcohols using molecular oxygen as benign oxidant. Pyrolysis nitrogen-ligated cobalt(II) acetate supported on commercial carbon transforms typical homogeneous complexes to highly active and selective Co3O4-N@C materials. By applying these in presence oxygen, cross self-esterification esters proceeds good excellent yields.

Cobalt oxide/cobalt-based nanoparticles featuring a core-shell structure and nitrogen-doped graphene layers on alumina are obtained by pyrolysis of Co(OAc)2/phenanthroline. The resulting material (Co3O4-Co/NGr@α-Al2O3) was successfully applied in the catalytic hydrogenation variety N-heteroarenes including quinolines, acridines, benzo[h], 1,5-naphthyridine as well unprotected indoles. peculiar novel heterogeneous catalyst enables activation molecular hydrogen at comparably low temperature....

The activity of plasmonic Au–TiO2 catalysts for solar hydrogen production from H2O/MeOH mixtures was found to depend strongly on the support phase (anatase, rutile, brookite, or composites thereof) as well specific structural properties caused by method Au deposition (sol-immobilization, photodeposition, deposition–precipitation). Structural and electronic rationale have been identified this behavior. Using a combination spectroscopic in situ techniques (EPR, XANES, UV–vis spectroscopy),...

Abstract Selective hydrogenations of (hetero)arenes represent essential processes in the chemical industry, especially for production polymer intermediates and a multitude fine chemicals. Herein, we describe new type well-dispersed Ru nanoparticles supported on nitrogen-doped carbon material obtained from ruthenium chloride dicyanamide facile scalable method. These novel catalysts are stable display both excellent activity selectivity hydrogenation aromatic ethers, phenols as well other...

Supported V2O5/Ce1–xTixO2 (3, 5, and 7 wt % V; x = 0, 0.1, 0.3, 0.5, 1) bare supports have been tested in the selective catalytic reduction (SCR) of NO by NH3 at different gas hourly space velocities (GHSVs) were comprehensively characterized using XRD, pseudo situ XPS, UV–vis DRS as well EPR DRIFTS operando mode. The best V/Ce1–xTixO2 (x 0.5) catalysts showed almost 100% conversion N2 selectivity already 190 °C with a GHSV value 70000 h–1, which belongs to performances observed so far...

This work presents the determination of corrosion characteristics CrCoNi (medium entropy alloy) and CrMnFeCoNi (high in 0.1 M NaCl H2SO4. The morphology chemical composition oxide layers formed on were comparatively analyzed by scanning Kelvin probe microscopy (SKPFM) electron (SEM) supported with analysis means inductively coupled plasma mass spectrometry (ICP-MS) X-Ray photoelectron spectroscopy (XPS). 3p core level peaks showed that layer (native after anodic passivation) consisted mainly...

Structure and stability of an iron-based catalyst for the oxygen reduction reaction, prepared by heat treatment carbon-supported iron(III) tetramethoxyphenylporphyrin chloride (FeTMPP−Cl), were investigated. The in acid electrolyte was examined with rotating (ring) disk electrode. measurements confirmed that H2O2 is generated as a byproduct reduction. structural elucidation showed porphyrin decomposes during treatment. Nitrogen atoms heat-treated become bonded at edge graphene layers...

The active sites of supported gold catalysts, favoring the adsorption CO groups acrolein and subsequent reaction to allyl alcohol, have been identified as edges nanoparticles. After our recent finding that this preferentially occurs on single crystalline particles rather than multiply twinned ones, paper reports a new approach distinguish different features particle morphology. Elucidation site issue cannot be simply done by varying size particles, since effects faceting may interfere....

The environmentally benign synthesis of carbon−nitrogen bonds continues to be an active and challenging field chemical research. Here, a novel, method for the direct coupling sulfonamides alcohols is described. Despite importance sulfonamide derivatives as intermediates in drug synthesis, till now such transformations are rarely known. For first time domino dehydrogenation-condensation-hydrogenation sequence has been realized presence nanostructured catalyst. magnetic property catalyst...

FeTMPPCl impregnated on a carbon black was heat-treated to different temperatures. The obtained catalysts were characterized before and after acid-leaching by structural chemical analyses. On the basis of characterization it concluded that those -centers in which iron is mesomerically bonded four nitrogen atoms are catalyzing oxygen reduction reaction (ORR). X-ray induced photoelectron spectroscopy as well Mössbauer revealed higher pyrolysis temperatures cause partial shift electron density...

Abstract A general epoxidation of aromatic and aliphatic olefins has been developed under mild conditions using heterogeneous Co x O y –N/C ( =1,3; =1,4) catalysts tert ‐butyl hydroperoxide as the terminal oxidant. Various stilbenes alkenes, including renewable olefins, vitamin cholesterol derivatives, were successfully transformed into corresponding epoxides with high selectivity often good yields. The cobalt oxide catalyst can be recycled up to five times without significant loss activity...

This work presents the preparation and investigation of pyrolyzed cobalt–tetramethoxyphenylporphyrin (CoTMPP) supported by iron oxalate with without sulfur as electrocatalysts for oxygen reduction reaction (ORR) in acid media. A method which needs no addition carbon supports allows structural pyrolysis products X-ray photoemission spectroscopy, Raman diffractometry any interferences a support. Already low metal loading, rotating ring disk electrode measurements reveal high ORR activity...

The functionalized anilines have been synthesized by the transfer hydrogenation of nitroarenes using cobalt oxide-based nanocatalysts.

Novel heterogeneous cobalt-based catalysts have been prepared by pyrolysis of cobalt complexes with nitrogen ligands on different inorganic supports. The activity and selectivity the resulting materials in hydrogenation nitriles carbonyl compounds is strongly influenced modification support nitrogen-containing ligand. optimal catalyst system ([Co(OAc)2/Phen@α-Al2O3]-800 = Cat. E) allows for efficient reduction both aromatic aliphatic including industrially relevant dinitriles to primary...

For the first time N-graphitic-modified cobalt nanoparticles (Co/phen@SiO2-800) are shown to be active in semihydrogenation of alkynes alkenes. Key success for efficient catalysis is both modification metal by nitrogen-doped graphitic layers and use silica as support. Several internal converted Z isomer high yields with up 93% selectivity. In addition, a variety terminal alkynes, including sensitive functionalized compounds, readily into Notably, this non-noble-metal catalyst allows...

Photocatalytic hydrogen evolution rates and structural properties as well charge separation, electron transfer, stabilization have been analyzed in advanced sol–gel-derived carbon nitrides (SG-CN) pyrolyzed at different temperatures (350–600 °C) bulk polymeric nitride reference samples (CN) by XRD, XPS, FTIR, UV–vis, Raman, photoluminescence situ EPR spectroscopy. SG-CN show about 20 times higher H2 production than CN. This is due to their porous structure, partial disorder, high surface...