The unique linear linkage of isobutene to generate highly valuable C8 precursors for plasticizers is feasible by using special nickel catalysts. (4-Cyclooctene-1-yl)(1,1,1,5,5,5-hexafluoro-2,4-acetylacetonato)nickel and aluminum-alkyl-activated nickel acetylacetonates produce isobutene dimers with high selectivities of up to 95%. Moreover, selectivity for the head-to-head products (2,5-dimethylhexenes) is remarkably high at up to 99%. Additionally, novel C12 isobutene trimers are also formed with a very high selectivity of up to 99% for the linear linkage. The trimer structure (2,5,8-trimethylnonenes) reflects the stepwise characteristic of the reaction mechanism. Pathways of insertion and activation and the deactivation processes of the catalyst are discussed in detail.
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http://dx.doi.org/10.1002/asia.201301263 | DOI Listing |
Sci Bull (Beijing)
December 2024
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address:
Divergent synthesis of valuable molecules through common starting materials and metal catalysis represents a longstanding challenge and a significant research goal. We here describe chemodivergent, highly enantio- and regioselective nickel-catalyzed reductive and dehydrogenative coupling reactions of alkynes, aldehydes, and silanes. A single chiral Ni-based catalyst is leveraged to directly prepare three distinct enantioenriched products (silyl-protected trisubstituted chiral allylic alcohols, oxasilacyclopentenes, and silicon-stereogenic oxasilacyclopentenes) in a single chemical operation.
View Article and Find Full Text PDFLangmuir
January 2025
College of Chemical Engineering, Sichuan University of Science and Engineering, Zigong, Sichuan 643000, China.
With the rapid development of electroless nickel (Ni) plating industry, a large amount of Ni complex wastewater is inevitably produced, which is a serious threat to the ecological environment. Herein, a novel Mn-N codoped active carbon (Mn-N@AC) catalyst with high catalytic ozonation ability was synthesized by the impregnation precipitation method and was characterized by BET, XRD, Raman, SEM, FTIR, and TPR. Meanwhile, Mn-N@AC showed excellent catalytic ozonation ability, stability, and applicability.
View Article and Find Full Text PDFChem Asian J
January 2025
Charotar University of Science and Technology, Physical Science, P.D. Patel Institute of Applied Sciences, 388421, Changa, INDIA.
The primary obstacle in electrolyzing water is that prolonged large-current operation quickly degrades performance, making it difficult to achieve efficient and continuous hydrogen evolution at high current densities. This work prepared sulfur-doped nickel ferrite nanocomposites using the simple hydrothermal method to improve electrocatalytic green hydrogen production at high-current densities. X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used to analyze the crystalline structure, morphology, and chemical composition of the synthesized nanocomposites.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources, College of Chemistry, Xinjiang University, Urumqi 830017, Xinjiang, PR China. Electronic address:
Discovering a valid approach to achieve a novel and efficient water splitting catalyst is essential for the development of hydrogen energy technology. Herein, unique hollow-structured ruthenium (Ru)-doped nickel-cobalt oxide (Ru-NiO/CoO/NF) nanocube arrays are fabricated as high-efficiency bifunctional electrocatalysts for hydrogen evolution reaction (HER)/urea oxidation reaction (UOR) through combined electronic and vacancy engineering. The structural characterization and experimental results indicate that the doping of Ru can not only effectively modulate the electronic structure of Ru-NiO/CoO/NF, but also increase the content of oxygen vacancies in the structure of Ru-NiO/CoO/NF to stabilize the existence of oxygen vacancies during the catalytic process.
View Article and Find Full Text PDFChemistry
December 2024
Technische Universitat Berlin, Chemistry, Strasse des 17. Juni 135, Sekr. C2, 10623, Berlin, GERMANY.
Water-assisted electrocatalytic oxidation of alcohols into valuable chemicals is a promising strategy to circumvent the sluggish kinetics of water oxidation, while also reducing cell voltage and improving energy efficiency. Recently, transition metal (TM)-based catalysts have been investigated for anodic alcohol oxidation, but success has been limited due to competition from the oxygen evolution reaction (OER) within the working regime. In this study, NiCo-based Prussian blue analog (PBA) was electrochemically activated at the anodic potential to produce a Co-Ni(O)OH active catalyst with a nanosheet-like architecture.
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