Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Ergebnis 20 von 1207

Details

Autor(en) / Beteiligte
Titel
Nanoengineered Design of inside‐Heating Hot Nanoreactor Surrounded by Cool Environment for Selective Hydrogenations
Ist Teil von
  • Advanced materials (Weinheim), 2023-08, Vol.35 (31), p.e2302793-n/a
Ort / Verlag
Germany: Wiley Subscription Services, Inc
Erscheinungsjahr
2023
Link zum Volltext
Quelle
Wiley Online Library - AutoHoldings Journals
Beschreibungen/Notizen
  • Catalysts with designable intelligent nanostructure may potentially drive the changes in chemical reaction techniques. Herein, a multi‐function integrating nanocatalyst, Pt‐containing magnetic yolk‐shell carbonaceous structure, having catalysis function, microenvironment heating, thermal insulation, and elevated pressure into a whole is designed, which induces selective hydrogenation within heating‐constrained nanoreactors surrounded by ambient environment. As a demonstration, carbonyl of α, β‐unsaturated aldehydes/ketones are selectively hydrogenated to unsaturated alcohols with a >98% selectivity at a nearly complete conversion under mild conditions of 40 °C and 3 bar instead of harsh requirements of 120 °C and 30 bar. It is creatively demonstrated that the locally increased temperature and endogenous pressure (estimated as ≈120 °C, 9.7 bar) in the nano‐sized space greatly facilitate the reaction kinetics under an alternating magnetic field. The outward‐diffused products to the “cool environment” remain thermodynamically stable, avoiding the over‐hydrogenation that often occurs under constantly heated conditions of 120 °C. Regulation of the electronic state of Pt by sulfur doping of carbon allows selective chemical adsorption of the CO group and consequently leads to selective hydrogenation. It is expected that such a multi‐function integrated catalyst provides an ideal platform for precisely operating a variety of organic liquid‐phase transformations under mild reaction conditions. A multi‐function nanocatalyst, integrating locally inside‐heating, thermal insulation, and high‐dispersed Pt into a whole, induces selective hydrogenations within heat‐constrained nanoreactors (120 °C) surrounded by a cool environment (40 °C). A 20.1‐fold increase in reaction rate is achieved compared to the conventional outside‐in heating. The diffusion of target products into a cool environment ensures the high selectivity (>98%) under high conversion (≈100%).

Weiterführende Literatur

Empfehlungen zum selben Thema automatisch vorgeschlagen von bX