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The oxygen evolution reaction (OER) is the bottleneck reaction of water splitting, which can be used to generate green hydrogen from renewable electricity. Cobalt iron oxyhydroxides (CoFeOxHy) are among the most active OER catalysts in alkaline medium. However, the active sites of these catalysts remain unclear. Here we use operando ultraviolet-visible (UV-Vis), X-ray absorption, and Raman spectroscopy to reveal oxidations of both Fe and Co ions in CoFeOxHy during the OER. By analyzing samples with different Fe contents and thickness, we find that the concentration of Fe4+ species at the surface, but not the concentration of Co4+ in the bulk, scales with the catalytic activity. These results indicate an Fe4+-containing active site in CoFeOxHy.

Oxidative amination of alkenes via amidyl radical addition is potentially an efficient method to generate allylic amines, which are versatile synthetic intermediates to bioactive compounds and organic materials. Here by combining photochemical generation of amidyl radicals with Cu-mediated β-H elimination of alkyl radicals, we have developed an intermolecular oxidative amination of unactivated alkenes. The reaction relies on tandem photoredox and copper catalysis, and works for both terminal and internal alkenes. The radical nature of the reaction and the mild conditions lead to high functional group tolerance., Oxidative amination via amidyl radical addition of unactivated alkenes was realized by dual photoredox and copper catalysis.

Convergent paired electrosynthesis is an energy-efficient approach in organic synthesis; however, it is limited by the difficulty to match the innate redox properties of reaction partners. Here we use nickel catalysis to cross-couple the two intermediates generated at the two opposite electrodes of an electrochemical cell, achieving direct arylation of benzylic C–H bonds. This method yields a diverse set of diarylmethanes, which are important structural motifs in medicinal and materials chemistry. Preliminary mechanistic study suggests oxidation of a benzylic C–H bond, Ni-catalyzed C–C coupling, and reduction of a Ni intermediate as key elements of the catalytic cycle., A direct arylation of benzylic C–H bonds is achieved by integrating Ni-catalyzed benzyl–aryl coupling into convergent paired electrolysis.

Single-atom catalysts are emerging as primary catalysts for many reactions due to their 100% utilization of active metal centers leading to high catalytic efficiencies. Herein, we report the use of a single-atom Co catalyst for the oxidative cleavage of the β-O-4 bonds of lignin model compounds at a low oxygen pressure. Under the optimized reaction conditions, the conversion of 2-(2-methoxyphenoxy)-1-phenylethanol up to 95% with high selectivities was achieved with a variety of substrates investigated. The reusability of the Co catalyst with a high catalytic efficiency indicates its potential application in the oxidative cleavage of C–O bonds.

Amides are ubiquitous molecules in nature and in synthetic chemistry. Here we report a convenient and efficient method to synthesize N-aryl amides via amidation of esters with nitroarenes. In the presence of manganese metal, this amidation proceeded smoothly without the need for additional catalysts or ligands. Various esters and nitroarenes are suitable substrates to afford a wide range of N-aryl amides, including bio-active molecules and intermediates to drug molecules.

Photoredox catalysis has been developed to achieve oxidative C-H chlorination of aromatic compounds using NaCl as the chlorine source and Na2S2O8 as the oxidant. The reactions occur at room temperature and exhibit exclusive selectivity for C(sp2)-H bonds over C(sp3)-H bonds. The method has been used for the chlorination of a diverse set of substrates, including the expedited synthesis of key intermediates to bioactive compounds and a drug.

The development of efficient and Earth-abundant oxygen evolution reaction (OER) catalysts is essential for the generation of renewable hydrogen. The synthesis of nanoporous and high-surface-area catalysts remains challenging. Herein, we show that large nano-cubes of perovskite hydroxide CoSn(OH)(6) can be electrochemically etched to form a highly active OER catalyst, reaching 10mA cm(-2) at an overpotential (eta) of only 274 mV. The good catalytic activity was attributed to the formation of hierarchical nanoporous CoOOH particles, which were created by selective dissolution of Sn hydroxides. Crystal defects of oxygen vacancies appear to be important for the formation of active catalysts.

Several imidazolium-based ionic liquids significantly enhance the activity of MoO2 for electrochemical reduction of CO2. The overpotential of CO2 reduction is as low as 40 mV. The ionic liquids act as both electrolytes and co-catalysts, which not only leads to lower overpotentials, but also alters the product selectivity.

Electrochemical water splitting into hydrogen and oxygen is a promising method for solar energy storage. The development of efficient electrocatalysts for water splitting has drawn much attention. However, catalysts that are active for both the hydrogen evolution and oxygen evolution reactions are rare. Herein, we show for the first time that nickel phosphide (Ni2P), an excellent hydrogen evolving catalyst, is also highly active for oxygen evolution. A current density of 10 mA cm−2 is generated at an overpotential of only 290 mV in 1 M KOH. The high activity is attributed to the core–shell (Ni2P/NiOx) structure that the material adopts under catalytic conditions. The Ni2P nanoparticles can serve as both cathode and anode catalysts for an alkaline electrolyzer, which generates 10 mA cm−2 at 1.63 V.

A highly active and stable electrochemical catalyst of nanoporous molybdenum carbide nanowires (np-Mo2C NWs) has been developed for hydrogen evolution reaction (HER). The np-Mo2C NWs were synthesized simply by pyrolysis of a MoOx,/amine hybrid precursor with sub-nanosized periodic structure under an inert atmosphere. The enriched nanoporosity and large reactive surface of these highly dispersed nanowires with uniform Mo2C nanocrystallites provide an efficient electrocatalysis, leading to their superior HER activity with lower onset overpotential and higher current densities than Mo2C microparticles. This study opens a new perspective for the development of highly active non-noble electrocatalysts for hydrogen production from water splitting.

Rarely reported low cost molybdenum boride and carbide microparticles both of which are available in abundant quantities due to their widespread use in industry adsorb at aqueous acid 12 dichloroethane interfaces and efficiently catalyse the hydrogen evolution reaction in the presence of the organic electron donor decamethylferrocene. Kinetic studies monitoring biphasic reactions by UV/vis spectroscopy and further evidence provided by gas chromatography highlight (a) their superior rates of catalysis relative to other industrially significant transition metal carbides and silicides as well as a main group refractory compound and (b) their highly comparable rates of catalysis to Pt microparticles of similar dimensions. Insight into the catalytic processes occurring for each adsorbed microparticle was obtained by voltammetry at the liquid liquid interface.© 2013 the Owner Societies.

An improved synthesis of pincer ligand bis[(2-dimethylamino)phenyl]amine ((Me)N(2)NH) was reported. Reaction of the Li complex of (Me)N(2)N with suitable Pd, Pt, and Ru precursors gave the corresponding metal complexes. The structures of the Pd, Pt, and Ru complexes were determined. The Ru complex showed activity in catalytic transfer hydrogenation of aryl and alkyl ketones.

Cross coupling of non-activated alkyl halides is a potentially transformative methodology in organic synthesis. Herein we review the recent development of nickel-catalyzed coupling of non-activated alkyl halides. The current understanding of the mechanism of these coupling reactions is highlighted. As the mechanism is ligand-dependant, the perspective is organized according to the types of ligands employed in the catalysis.