304 research outputs found
Facile Synthesis of Mesoporous Manganese–Iron Nanorod Arrays Efficient for Water Oxidation
No full textWater splitting for the production
of oxygen is a promising strategy
to advance many renewable energy conversion systems, while the cost-effective
and green synthesis of a high-performance catalyst composed of earth-abundant
elements is still a big challenge. A facile and green synthesis of
nonprecious MnFe2O4 nanorod arrays at low temperature
is developed here, where the as-obtained hierarchical MnFe2O4 nanorod arrays exhibit mesoporous structure, large
surface area and nice dispersion. These fabricated mesoporous MnFe2O4 nanorod arrays are efficient for water oxidation
in 0.1 M NaOH, giving rise to a low overpotential of ∼0.315
VRHE at 10.0 mA cm–2, a high current
density (10 times higher than that of commercial 20 wt % Pt/C catalyst
at 1.80 VRHE) and largely enhanced stability. These performances
are much superior to previously reported electro-oxidation catalysts
as well as the state-of-the-art RuO2 and precious 20 wt
% Pt/C catalysts. In particular, this preparation method of MnFe2O4 nanorods is amenable to fast and cost-effective
production and shows promising applications in water splitting and
other clean energy systems
A Highly Diastereo- and Enantioselective Copper(I)-Catalyzed Henry Reaction Using a Bis(sulfonamide)−Diamine Ligand
No full textA series of bis(sulfonamide)−diamine (BSDA) ligands were synthesized from commercially available chiral α-amino alcohols and diamines. The chiral BSDA ligand 3a, coordinated with Cu(I), catalyzes the enantioselective Henry reaction with excellent enantioselectivity (up to 99%). Moreover, with the assistance of pyridine, a CuBr−3a system promotes the diastereoselective Henry reaction with various aldehyde substrates and gives the corresponding syn-selective adduct with up to a 99% yield and 32.3:1 syn/anti selectivity. The enantiomeric excess of the syn adduct was 97%
Transformation of Oxidation Products and Reduction of Estrogenic Activity of 17β-Estradiol by a Heterogeneous Photo-Fenton Reaction
No full textA novel photo-Fenton catalyst, α-FeOOH loaded resin (α-FeOOHR), was synthesized and evaluated through transformation of a steroidal endocrine disrupting compounds (EDC), 17β-estradiol (E2), under weak UV irradiation in the presence of H2O2. E2 photodegradation intermediates elucidated in detail by GC/MS and LC/MS/MS analyses and detailed reaction pathways are proposed. A yeast-based estrogen screen for E2 and its photodegradation intermediates was performed to measure the reduction of estrogenic activity in different water matrices during the heterogeneous photo-Fenton process. The results showed that α-FeOOHR not only degraded E2 but also removed the estrogenic activity originating from E2, its degradation intermediates, and its products. However, the water matrix present in drinking water may impact estrogenic activity reduction. The results are important to evaluate the ability of photo-Fenton advanced oxidation processes in reducing EDCs and their associated estrogenicity from drinking water
Synthetic Studies on Ecteinascidin-743: Constructing a Versatile Pentacyclic Intermediate for the Synthesis of Ecteinascidins and Saframycins
No full textThe asymmetric synthesis of a highly functionalized pentacyclic tetrahydroisoquinoline relevant to the ecteinascidin, saframycin, safracin, and
renieramycin family of antitumor alkaloids is described
- …
