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991.
Peili Zhang Xia Sheng Xiaoyu Chen Zhiyong Fang Jian Jiang Mei Wang Fusheng Li Lizhou Fan Yansong Ren Biaobiao Zhang Brian J. J. Timmer Mrten S. G. Ahlquist Licheng Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(27):9253-9257
The use of water as an oxygen and hydrogen source for the paired oxygenation and hydrogenation of organic substrates to produce valuable chemicals is of utmost importance as a means of establishing green chemical syntheses. Inspired by the active Ni3+ intermediates involved in electrocatalytic water oxidation by nickel‐based materials, we prepared NiBx as a catalyst and used water as the oxygen source for the oxygenation of various organic compounds. NiBx was further employed as both an anode and a cathode in a paired electrosynthesis cell for the respective oxygenation and hydrogenation of organic compounds, with water as both the oxygen and hydrogen source. Conversion efficiency and selectivity of ≥99 % were observed during the oxygenation of 5‐hydroxymethylfurfural to 2,5‐furandicarboxylic acid and the simultaneous hydrogenation of p‐nitrophenol to p‐aminophenol. This paired electrosynthesis cell has also been coupled to a solar cell as a stand‐alone reactor in response to sunlight. 相似文献
992.
Cong Ding Yage Chen Haozheng Li Bingyao Wang Qi Wei Huajun Tang Shaokang Jia Zhiyong He Ping Wang Xiang Zhou 《中国化学快报》2019,30(7):1393-1396
Lysosome-selective Raman probe, Lyso-BADY, was created with improved Raman signal intensity, stability as well as specificity under the visualization of hyperspectral stimulated Raman scattering (SRS) microscopy. Prolonged exposure to irradiation further proved its photostability and potentiality for continuous imaging. 相似文献
993.
A series of Keggin‐type heteropolyacid‐based heterogeneous catalysts (Co‐/Fe‐/Cu‐POM‐octyl‐NH3‐SBA‐15) were synthesized via immobilized transition metal mono‐ substituted phosphotungstic acids (Co‐/Fe‐/Cu‐POM) on octyl‐amino‐co‐functionalized mesoporous silica SBA‐15 (octyl‐NH2‐SBA‐15). Characterization results indicated that Co‐/Fe‐/Cu‐POM units were highly dispersed in mesochannels of SBA‐15, and both types of Brønsted and Lewis acid sites existed in Co‐/Fe‐/Cu‐POM‐octyl‐NH3‐SBA‐15 catalysts. Co‐POM‐octyl‐NH3‐SBA‐15 catalyst showed excellent catalytic performance in H2O2‐mediated cyclohexene epoxidation with 83.8% of cyclohexene conversion, 92.8% of cyclohexene oxide selectivity, and 98/2 of epoxidation/allylic oxidation selectivity. The order of catalytic activity was Co‐POM‐octyl‐NH3‐SBA‐15 > Fe‐POM‐octyl‐NH3‐SBA‐15 > Cu‐POM‐octyl‐NH3‐SBA‐15. In order to obtain insights into the role of ‐octyl moieties during catalysis, an octyl‐free catalyst (Co‐POM‐NH3‐SBA‐15) was also synthesized. In comparison with Co‐POM‐NH3‐SBA‐15, Co‐POM‐octyl‐NH3‐SBA‐15 showed enhanced catalytic properties (viz. activity and selectivity) in cyclohexene epoxidation. Strong chemical bonding between ‐NH3+ anchored on the surface of SBA‐15 and heteropolyanions resulted in excellent stability of Co‐POM‐octyl‐NH3‐SBA‐15 catalyst, and it could be reused six times without considerable loss of activity. 相似文献
994.
Guangdong Sun Yi Huang Lingling Lv Dapeng Li Qinguo Fan Yongqiang Li Jianzhong Shao 《Journal of polymer science. Part A, Polymer chemistry》2021,59(15):1686-1700
In situ viscosity kinetics models for blue light induced radical polymerization of acrylamide (AM) were proposed and established with camphorquinone/4-(dimethylamino)-2-ethylbenzoate/diphenyl iodonium hexafluorophosphateas the photoinitiators. In order to minimize the impact of shear effect on polymer network, a constant shear stress technique of photo-rheometry was proposed to characterize in-situ viscosity behavior of acrylamide solution during the photopolymerization. The effect of various factors, for example, the dosages of initiator, monomer, and light intensities, on viscosity, polymerization and gelation behavior of AM solution was systematically analyzed. The viscosity advancement behavior was shaped by the joint action of the movement, growth and entanglement of molecular chains, and shear orientation. Different power-law kinetic models were found in three curves, time-related viscosity, shear rate-related viscosity and time-related shear rate. Such school of thought on constructing the viscosity advancement model provides a new theory and method of systematical studying on the photorheological theories. Furthermore, a trinitarian theoretical model that represented the access from the microscopic kinetics of free radical polymerization to the movement behavior of polymer chains was successfully established by mapping the photoinduced viscosity kinetics model onto the polymerization and crosslinking kinetics model. 相似文献
995.
Weibin Zhang Woochul Yang Yingkai Liu Zhiyong Liu Fuchun Zhang 《Frontiers of Physics》2022,17(6):63509
By high-throughput calculations, 13 thermally and environmentally stable Janus MA2Z4 monolayers were screened from 104 types of candidates. The 13 stable monolayers have very high charge carrier concentrations (×1015 cm−2), which are better than those of the well-known graphene and TaS2. Because of their excellent conductivity, the 6 monolayers with band gaps less than 0.5 eV are identified as potential electrode materials for hydrogen evolution reaction applications. For potential applications as photoelectric or photocatalytic materials, bandgaps (Eg-HSE) higher than 0.5 eV remained, which resulted in 7 potential candidates. Based on optical absorption analysis in the visible-light range, H-HfSiGeP4 and H-MoSiGeP4 have higher absorption ability and optical conductivity, which is quite impressive for optoelectronic, solar cell device, and photocatalysis applications. Additionally, the transmittance coefficient of Janus MA2Z4 monolayers is approximately 70%−80% in the visible-light range, which implies that these monolayers show good light transmittance. For potential applications as photocatalysts, the redox potential and charge effective mass analysis indicate that H-HfSiGeP4, H-MoSiGeP4, T-ScSiGeN4, and T-ZrSiGeN4 are suitable photocatalysts for CO2 reduction reactions. Using high-throughput identification, 13 types of new and stable Janus MA2Z4 monolayers were explored, and the basic properties and potential applications were investigated, which can reduce the time for experiments and provide basic data for the material genome initiative. 相似文献
996.
997.
Yong‐Miao Shen Yi‐Jun Du Min‐Feng Zeng Duo Zhi Sheng‐Xian Zhao Lin‐Mei Rong Shao‐Qin Lv Lin Du Chen‐Ze Qi 《应用有机金属化学》2010,24(9):631-635
A novel palladium catalyst supported on shell powder has been prepared, and its application to the Heck reaction of aryl iodides with olefins has been reported. The results showed that the novel catalyst had extremely high activities for the reactions with the average yield over 90%. Also, this catalyst showed excellent stability in Heck reactions, being reused three times. The catalyst was characterized by X‐ray powder diffraction and field‐emission scanned electron microscopy images, and the energy dispersive X‐ray analyzer. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
998.
Using first-principles technique, the crystal structure of cementite-type Fe3N is predicted. The average magnetic moment (Ms) of cementite-type Fe3N is also predicted as 1.4929 μB/atom. The Ms of Fe3N is bigger than that of Fe3C, but smaller than that of Fe3B. Fe Ms between two different Fe sites in Fe3N are different (2.0541 and 2.0139 μB), which indicates that Fe Ms are sensitive to the local short-range order in the cementite-type crystal. The Ms of B, C and N are ?0.3525, ?0.2474 and ?0.1102 μB/atom in Fe3X (X = B, C, N), respectively. The chemical bonds of Fe3X (X = B, C, N) take on metallicity, covalence, and ionicity. The ionicity of Fe3X (X = B, C, N) strengthens and the covalence of Fe–X weakens, going from Fe3B, Fe3C to Fe3N. 相似文献
999.
1000.