In typical catalytic organic transformations, transition metals in catalytically active complexes are present in their most stable valence states, such as palladium(0) and (II). However, some dimeric monovalent metal complexes can be stabilized by auxiliary ligands to form diamagnetic compounds with metal-metal bonding interactions. These diamagnetic compounds can act as catalysts while retaini...

Four types of nickel catalysts supported on aluminum oxide (Ni/Al2O3) with different nickel loadings were synthesized using the co-precipitation method and were used for the hydrogenation of levulinic acid (LA) to prepare γ-valerolactone (GVL). The synthesized Ni/Al2O3 catalysts exhibited excellent catalytic activity in dioxane, and the activity of the catalysts was excellent even after being u...

The possibility of optimizing the composition and the structures of the nickel catalysts and the pretreatment and reaction conditions for carbon dioxide reforming with methane is investigated. The optimum catalyst and the pretreatment and reaction conditions are determined employing the orthogonal and uniform design methods. The optimum nickel catalyst gives promising catalytic performance in t...

Valorization of lignin is essential for the economics of future lignocellulosic biorefineries. Lignin is converted into novel polymer building blocks through four steps: catalytic hydroprocessing of softwood to form 4-alkylguaiacols, their conversion into 4-alkylcyclohexanols, followed by dehydrogenation to form cyclohexanones, and Baeyer-Villiger oxidation to give caprolactones. The formation ...

The catalytic reduction of SO2 to elemental sulfur by methane was studied over ceria-based catalysts. Both La-doped and undoped ceria were found to catalyze the SO2 reduction by CH4 in the temperature range of 550–750◦C at atmospheric pressure and with feed gases containing a molar ratio of CH4/SO2 = 0.5–3. At temperatures below ∼550◦C, the catalyst surface is capped by SO2. The reaction light-...

A series of iminopyridine ligated Co(II) (1a–7a) and Ni(II) (1b–7b) complexes were synthesized. The structures of complexes 3a, 4a, 5a, 7a, 5b, and 6b were determined by X-ray crystallographic analyses. Complex 3a formed a chloro-bridged dimer, whereas 4a, 5a, and 7a, having a substituent (4a, 5a: CH3; 7a: Br) at the 6-position of pyridine, producing the solid structures with a single ligand co...

In this work, a nickel-modified glassy carbon electrode (GCE) was prepared using a potentiostatic method in 0.1 M acetate buffer solution at pH 4.0 containing 1.0 mM nickel nitrate. Nickel hydroxide nanoparticles were prepared using consecutive potential scanning in 0.1 M NaOH solution. The as-prepared catalyst was characterized by field emission scanning electron microscopy and electrochemical...

We report a robust and direct route to fabricate a three-dimensional nano-foam of few-layer graphene (3D-NFG) with large area coverage via a chemical vapor deposition (CVD) technique. Pyrolysis of polymer/nickel precursor film under a hydrogen environment, simply prepared by spin-coating, leads to the creation of nano-foam in the film and the reduction process of nickel ions. Carbonized-C and t...

Many nickel-based catalysts have been reported for cross-coupling reactions of nonactivated alkyl halides. The mechanistic understanding of these reactions is still primitive. Here we report a mechanistic study of alkyl-alkyl Kumada coupling catalyzed by a preformed nickel(II) pincer complex ([(N2N)Ni-Cl]). The coupling proceeds through a radical process, involving two nickel centers for the ox...