排序方式: 共有129条查询结果,搜索用时 15 毫秒
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WilhelmF. Maier Klaus Stwe Simone Sieg 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2007,119(32):6122-6179
Hochdurchsatztechniken zur Entdeckung, Entwicklung und Optimierung von Materialien und Katalysatoren gewinnen zunehmend an Akzeptanz in der Industrie. Über die Jahre ist eine relative, synchron verlaufende Entwicklung von Techniken zur parallelisierten Herstellung und Charakterisierung mit dazugehöriger Software und Informationstechnologien zu verzeichnen. Im vorliegenden Aufsatz wird versucht, einen umfassenden Überblick über den Stand der Technik an ausgewählten Beispielen zu vermitteln. Datenbanken, “Design of Experiment”, Data‐Mining‐Techniken, Modellierungstechniken und Entwicklung evolutionärer Strategien werden ebenso angesprochen wie die vielen komplexen Materialien, für deren Erforschung bereits geeignete Techniken entwickelt wurden. Unterschiedlichste Methoden zur parallelisierten Synthese führen zu Einzelsubstanz‐ oder Gradientenbibliotheken für elektronische und optische Materialien ebenso wie für Polymere und Katalysatoren oder anhand von Formulierungsstrategien erzeugten Produkten. Viele Beispiele illustrieren die unterschiedlichsten Insellösungen und dokumentieren eine bisher kaum wahrgenommene Vielfalt an neuen Verfahren für Synthese und Analyse nahezu beliebiger Materialien. Der Aufsatz endet mit einer Zusammenfassung literaturbekannter Erfolge und einer Abschätzung von noch vorhandenen Problemen und Zukunftsaufgaben. 相似文献
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Rahul Majee Arun Kumar Dr. Tisita Das Dr. Sudip Chakraborty Prof. Dr. Sayan Bhattacharyya 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(7):2903-2911
Five-fold intertwined AgxNi1−x (x=0.01–0.25) heterogeneous alloy nanocrystal (NC) catalysts, prepared through unique reagent combinations, are presented. With only ca. 5 at % Ag (AgNi-5), Pt-like activity has been achieved at pH 14. To reach a current density of 10 mA cm−2 the extremely stable AgNi-5 requires an overpotential of 24.0±1.2 mV as compared to 20.1±0.8 mV for 20 % Pt/C, both with equal catalyst loading of 1.32 mg cm−2. The turnover frequency (TOF) is as high as 2.1 H2 s−1 at 50 mV (vs. RHE). Site-specific elemental analyses show the Ag:Ni compositional variation, where the apex and edges of the decahedra are Ag-rich, thereby exposing Ni onto the faces to achieve maximum charge transport for an exceptional pH universal HER activity. DFT calculations elucidate the relative H-atom adsorption capability of the Ni centers as a function of their proximity to Ag atom. 相似文献
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Long-Zhang Dong Lei Zhang Dr. Jiang Liu Qing Huang Meng Lu Dr. Wen-Xin Ji Prof. Ya-Qian Lan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(7):2681-2685
A series of stable heterometallic Fe2M cluster-based MOFs ( NNU-31-M , M=Co, Ni, Zn) photocatalysts are presented. They can achieve the overall conversion of CO2 and H2O into HCOOH and O2 without the assistance of additional sacrificial agent and photosensitizer. The heterometallic cluster units and photosensitive ligands excited by visible light generate separated electrons and holes. Then, low-valent metal M accepts electrons to reduce CO2, and high-valent Fe uses holes to oxidize H2O. This is the first MOF photocatalyst system to finish artificial photosynthetic full reaction. It is noted that NNU-31-Zn exhibits the highest HCOOH yield of 26.3 μmol g−1 h−1 (selectivity of ca. 100 %). Furthermore, the DFT calculations based on crystal structures demonstrate the photocatalytic reaction mechanism. This work proposes a new strategy for how to design crystalline photocatalyst to realize artificial photosynthetic overall reaction. 相似文献
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Zhishan Luo Yuanxing Fang Min Zhou Xinchen Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(18):6094-6098
Borocarbonitride (BCN) is a new type of photocatalyst, but bulk BCN shows a large band gap, and low surface area, and moderate activity for photocatalysis. Here, a three‐dimensional (3D) porous ceramic BCN aerogel was developed as an effective photocatalyst for relevant reactions. The unique structures endow the aerogel with an adjustable band gap and a high surface area, excellent stability, and improved crystallinity, which accelerates the separation and transfer of electron‐hole pairs and promotes catalytic kinetics, thus enhancing the performance of photocatalytic reactions for hydrogen generation and carbon dioxide reduction. This work supplies a low‐cost, convenient and green synthesis method for building ceramic aerogels, and it provides a simple colloid chemistry strategy combined with boron‐containing compounds to facilitate further innovative breakthroughs in the novel ceramic aerogel materials design and development in the field of catalysis. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(7):1871-1875
A biomimetic nickel bis‐diphosphine complex incorporating the amino acid arginine in the outer coordination sphere was immobilized on modified carbon nanotubes (CNTs) through electrostatic interactions. The functionalized redox nanomaterial exhibits reversible electrocatalytic activity for the H2/2 H+ interconversion from pH 0 to 9, with catalytic preference for H2 oxidation at all pH values. The high activity of the complex over a wide pH range allows us to integrate this bio‐inspired nanomaterial either in an enzymatic fuel cell together with a multicopper oxidase at the cathode, or in a proton exchange membrane fuel cell (PEMFC) using Pt/C at the cathode. The Ni‐based PEMFC reaches 14 mW cm−2, only six‐times‐less as compared to full‐Pt conventional PEMFC. The Pt‐free enzyme‐based fuel cell delivers ≈2 mW cm−2, a new efficiency record for a hydrogen biofuel cell with base metal catalysts. 相似文献
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