Stretchable large‐area high‐performance amorphous oxide thin‐film electronics fabricated using locally reinforced composite elastomers or wavy structures are functional while elongated by >200% and after 4000 stretching and relaxation cycles. 2D stretchable sensors, amplifiers, and circuits for wireless power transmission are conformably wrapped around arbitrary 3D structures and enable sensor systems for electronic implants and skins.
A hexapod
PtRuCu nanocrystalline alloy material is successfully
fabricated by a facile approach based on Stranski–Krastanov
growth and galvanic replacement and used as an efficient catalyst
for direct methanol fuel cells (DFMCs). Because of the synergetic
effect of metallic elements in the methanol oxidation, the activity
and durability of the prepared PtRuCu/C catalyst is significantly
enhanced. It has a mass activity of 1.35 A mgPt
–1 and a specific activity of 3.92 mA cm–2, which
are 3.8 and 8.2 times higher than those of Pt/C, respectively. Its
mass activity only decreases 27% after 800 CV cycles compared with
Pt/C (60% decline), indicating the admirable stability of the PtRuCu
catalyst.
Recently, in order to improve the energy conversion efficiency of direct polyol fuel cells, the engineering of effective Pd‐ and/or Pt‐based electrocatalysts to rupture CC bonds has received increasing attention. Here, an example is shown to synthesize highly uniform sub‐10 nm Pd‐Cu‐Pt twin icosahedrons by controlling the nucleation phase. Because of the synergies of the electronic effect, synergistic effect, geometric effect, and abundant surface active sites originating from the formation of near surface alloy and special icosahedral shape, the Pd‐Cu‐Pt twin icosahedrons exhibit excellent electrocatalytic performance in glycerol electrocatalysis at the operating temperature of direct alcohol fuel cells (70 °C) in KOH electrolyte. The Pd50.2Cu38.4Pt11.4 icosahedrons show mass activities of 9.7 A mg−1Pd+Pt and 13.7 A mg−1Pd. Furthermore, the Pd50.2Cu38.4Pt11.4 icosahedrons demonstrate long‐term durability in current–time test for 36 000 s and high in situ anti‐CO poisoning performance. In addition, the introduction of CO can enhance electro‐oxidation endurance on Pd50.2Cu38.4Pt11.4 icosahedrons, and the peak mass activity can reach to 14.4 A mg−1Pd+Pt. The in situ Fourier transform infrared spectroscopy spectra indicate that the Pd50.2Cu38.4Pt11.4 icosahedrons possess a high capacity to break CC bonds and may efficiently convert glycerol into CO2, thus improving the utilization efficiency of energy‐containing molecule glycerol.
A highly efficient synthesis of trans-alkenylazaarene under catalyst-free conditions was developed via the addition of methylazaarenes to N-sulfonyl aldimines and a subsequent C-N elimination in situ. A one-pot procedure for this addition-elimination was also developed. The reaction could tolerate a broad substrate scope and give the corresponding alkenylazaarenes in high yields.
A copper-catalyzed intramolecular trifluoromethylation of arylacrylamides leads to oxindole derivatives, effected with stable and inexpensive Langlois' reagent (CF3SO2Na). These reactions proceed via a radical process in water at room temperature. The aqueous solution can be recycled.
A new method for the tunable synthesis of 1,4-enedione directly from aromatic methyl ketone is described. This tandem reaction enables the construction of symmetric and unsymmetric 1,4-enediones with complete E-selectivity. Moreover, the resulting E-1,4-enedione could be transformed into a Z-isomer by irradiation with 23 W of white light.
Brønsted acid catalyzed tandem cyclization was found to be highly effective for the preparation of a series of polysubstituted 4-pyrones from diynones (yield up to 99%). 4-Pyridone and 3-pyrrolone derivatives were also selectively synthesized by employing NIS and/or Brønsted acid. NIS as an electrophilic reagent could promote these reactions efficiently and rapidly under very mild reaction conditions.
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