排序方式: 共有5条查询结果,搜索用时 876 毫秒
1
1.
Wenhao Ren Xin Tan Wanfeng Yang Chen Jia Shumao Xu Kaixue Wang Sean C. Smith Chuan Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(21):7046-7050
Polynary single‐atom structures can combine the advantages of homogeneous and heterogeneous catalysts while providing synergistic functions based on different molecules and their interfaces. However, the fabrication and identification of such an active‐site prototype remain elusive. Here we report isolated diatomic Ni‐Fe sites anchored on nitrogenated carbon as an efficient electrocatalyst for CO2 reduction. The catalyst exhibits high selectivity with CO Faradaic efficiency above 90 % over a wide potential range from ?0.5 to ?0.9 V (98 % at ?0.7 V), and robust durability, retaining 99 % of its initial selectivity after 30 hours of electrolysis. Density functional theory studies reveal that the neighboring Ni‐Fe centers not only function in synergy to decrease the reaction barrier for the formation of COOH* and desorption of CO, but also undergo distinct structural evolution into a CO‐adsorbed moiety upon CO2 uptake. 相似文献
2.
3.
Prof. Wenling Gu Hengjia Wang Lei Jiao Yu Wu Yuxin Chen Prof. Liuyong Hu Prof. Jingming Gong Prof. Dan Du Prof. Chengzhou Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(9):3562-3566
The traditional luminol–H2O2 electrochemiluminescence (ECL) sensing platform suffers from self-decomposition of H2O2 at room temperature, hampering its application for quantitative analysis. In this work, for the first time we employ iron single-atom catalysts (Fe-N-C SACs) as an advanced co-reactant accelerator to directly reduce the dissolved oxygen (O2) to reactive oxygen species (ROS). Owing to the unique electronic structure and catalytic activity of Fe-N-C SACs, large amounts of ROS are efficiently produced, which then react with the luminol anion radical and significantly amplify the luminol ECL emission. Under the optimum conditions, a Fe-N-C SACs–luminol ECL sensor for antioxidant capacity measurement was developed with a good linear range from 0.8 μm to 1.0 mm of Trolox. 相似文献
4.
Tianbo Li Dr. Fang Chen Dr. Rui Lang Dr. Hua Wang Yang Su Prof. Botao Qiao Prof. Aiqin Wang Prof. Tao Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(19):7500-7504
The hydroformylation of olefins is one of the most important homogeneously catalyzed industrial reactions for aldehyde synthesis. Various ligands can be used to obtain the desired linear aldehydes in the hydroformylation of aliphatic olefins. However, in the hydroformylation of aromatic substrates, branched aldehydes are formed preferentially with common ligands. In this study, a novel approach to selectively obtain linear aldehydes in the hydroformylation of styrene and its derivatives was developed by coupling with a water–gas shift reaction on a Rh single-atom catalyst without the use of ligands. Detailed studies revealed that the hydrogen generated in situ from the water–gas shift is critical for the highly regioselective formation of linear products. The coupling of a traditional homogeneous catalytic process with a heterogeneous catalytic reaction to tune product selectivity may provide a new avenue for the heterogenization of homogenous catalytic processes. 相似文献
5.
Qiming Sun Ning Wang Tianjun Zhang Risheng Bai Alvaro Mayoral Peng Zhang Qinghong Zhang Osamu Terasaki Jihong Yu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(51):18743-18749
Single‐atom catalysts are emerging as a new frontier in heterogeneous catalysis because of their maximum atom utilization efficiency, but they usually suffer from inferior stability. Herein, we synthesized single‐atom Rh catalysts embedded in MFI ‐type zeolites under hydrothermal conditions and subsequent ligand‐protected direct H2 reduction. Cs‐corrected scanning transmission electron microscopy and extended X‐ray absorption analyses revealed that single Rh atoms were encapsulated within 5‐membered rings and stabilized by zeolite framework oxygen atoms. The resultant catalysts exhibited excellent H2 generation rates from ammonia borane (AB) hydrolysis, up to 699 min?1 at 298 K, representing the top level among heterogeneous catalysts for AB hydrolysis. The catalysts also showed superior catalytic performance in shape‐selective tandem hydrogenation of various nitroarenes by coupling with AB hydrolysis, giving >99 % yield of corresponding amine products. 相似文献
1