Covalent anchoring of 1,4-dimethyl-1,4,7-triazacyclononane on silica gel is the first step in the preparation of a heterogenized Mn catalyst. When H O is used as the oxidant, this material can catalyze the vicinal cis-dihydroxylation of disubstituted olefins, as shown schematically here. Both enantiomers of the product are obtained.
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http://dx.doi.org/10.1002/(SICI)1521-3773(19990401)38:7<980::AID-ANIE980>3.0.CO;2-W | DOI Listing |
J Hazard Mater
January 2025
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China. Electronic address:
Nitrate pollution poses severe risks to aquatic ecosystems and human health. The electrocatalytic nitrate reduction reaction (NITRR) offers a promising environmental and economic solution for nitrate pollution treatment and nitrogen source recovery; however, it continues to experience limited efficiency in neutral electrolytes. This study explores the heterointerface activation effects of TiO/CuO heterogeneous catalysts with rutile (R-TiO) and anatase (A-TiO) phases and reveals that R-TiO is an active crystal phase with high nitrate reduction performance.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, South Korea.
Epoxides are versatile chemical intermediates that are used in the manufacture of diversified industrial products. For decades, thermochemical conversion has long been employed as the primary synthetic route. However, it has several drawbacks, such as harsh and explosive operating conditions, as well as a significant greenhouse gas emissions problem.
View Article and Find Full Text PDFACS Nano
January 2025
Creative Research Initiative Center for Nanospace-confined Chemical Reactions (NCCR), Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea.
Unlike homogeneous metal complexes, achieving absolute control over reaction selectivity in heterogeneous catalysts remains a formidable challenge due to the unguided molecular adsorption/desorption on metal-surface sites. Conventional organic surface modifiers or ligands and rigid inorganic and metal-organic porous shells are not fully effective. Here, we introduce the concept of "ligand-porous shell cooperativity" to desirably reaction selectivity in heterogeneous catalysis.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
University of York, Chemistry, Heslington, YO105DD, York, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
A tandem catalytic ensemble of solid-state molecular organometallic (SMOM) crystalline pre-catalysts are deployed under batch or flow conditions for the ethene to propene process (ETP). These catalysts operate at ambient temperature and low pressure, via sequential ethene dimerization, butenes isomerization and cross-metathesis. Under flow conditions the on-stream ethene conversion (55%), initial propene selectivity (92%), stability (71% selectivity after 7 hrs) and low temperature/pressures are competitive with the best-in-class heterogenous systems, marking a new, in crystallo, approach to ETP.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan, 81746-73441, Iran.
Biodiesel presents a sustainable alternative to fossil fuels, yet traditional homogeneous catalysts like sodium and potassium hydroxide face challenges with separation and reuse. Calcium oxide (CaO) is an effective heterogeneous catalyst for biodiesel production, but its chemical instability under reaction conditions restricts its long-term performance. This study introduces MOF-mediated synthesis (MOFMS) of heterogeneous catalysts, specifically CaO@ZnO and ZnO@CaO nanocomposites, from inexpensive and non-toxic metal salts and linkers in water.
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