Plasmonic Switching of the Reaction Pathway: Visible‐Light Irradiation Varies the Reactant Concentration at the Solid–Solution Interface of a Gold–Cobalt Catalyst. (18th June 2019)

• Record Type: Journal Article
• Authors: Peiris, Erandi; Sarina, Sarina; Waclawik, Eric R.; Ayoko, Godwin A.; Han, Pengfei; Jia, Jianfeng; Zhu, Huai‐Yong
• Is Part Of: Angewandte Chemie. Volume 131:Number 35(2019)
• Page Start: 12160
• Page End: 12164
• Publication Date: 2019-06-18
• Subjects: Photokatalyse mit sichtbarem Licht -- Plasmonische Metall-Nanopartikel -- Produktselektivität -- Reaktionspfade -- Selektive Adsorption; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201904452
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Product selectivity of alkyne hydroamination over catalytic Au2 Co alloy nanoparticles (NPs) can be made switchable by a light‐on/light‐off process, yielding imine (cross‐coupling product of aniline and alkyne) under visible‐light irradiation, but 1, 4‐diphenylbutadiyne in the dark. The low‐flux light irradiation concentrates aniline on the catalyst, accelerating the catalytic cross‐coupling by several orders of magnitude even at a very low overall aniline concentrations (1.0×10 −3 mol L −1 ). A tentative mechanism is that Au2 Co NPs absorb light, generating an intense fringing electromagnetic field and hot electrons. The sharp field‐gradient (plasmonic optical force) can selectively enhance adsorption of light‐polarizable aniline molecules on the catalyst. The light irradiation thereby alters the aniline/alkyne ratio at the NPs surface, switching product selectivity. This represents a new paradigm to modify a catalysis process by light. Abstract : Den Schalter umlegen : Die Produktselektivität zweier konkurrierender Reaktionen – Alkin‐Hydroaminierung und Alkin‐Alkin‐Homokupplung – auf katalytisch aktiven Au2 Co‐Nanopartikeln kann durch die Einstrahlung von sichtbarem Licht umgeschaltet werden. Lichteinstrahlung führt zu erhöhter Konzentration von Anilin auf dem Katalysator, was die Kreuzkupplung stark beschleunigt, während im Dunkeln die Homokupplung zweier Alkinmoleküle bevorzugt wird.