title: Visible-light-enhanced catalytic oxidation reactions on plasmonic silver nanostructures.
abstract: Catalysis plays a critical role in chemical conversion, energy production and pollution mitigation. High activation barriers associated with rate-limiting elementary steps require most commercial heterogeneous catalytic reactions to be run at relatively high temperatures, which compromises energy efficiency and the long-term stability of the catalyst. Here we show that plasmonic nanostructures of silver can concurrently use low-intensity visible light (on the order of solar intensity) and thermal energy to drive catalytic oxidation reactions--such as ethylene epoxidation, CO oxidation, and NH₃ oxidation--at lower temperatures than their conventional counterparts that use only thermal stimulus. Based on kinetic isotope experiments and density functional calculations, we postulate that excited plasmons on the silver surface act to populate O₂ antibonding orbitals and so form a transient negative-ion state, which thereby facilitates the rate-limiting O₂-dissociation reaction. The results could assist the design of catalytic processes that are more energy efficient and robust than current processes.
authors: Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors: Phillip
authors: P
authors: Christopher
authors: Hongliang
authors: H
authors: Xin
authors: Suljo
authors: S
authors: Linic
references: J Chem Phys. 2007 May 21;126(19):194702
references: 17523823
references: J Am Chem Soc. 2008 Aug 27;130(34):11264-5
references: 18665594
references: Science. 2010 Apr 9;328(5975):224-8
references: 20378815
references: Science. 1999 Aug 13;285(5430):1042-5
references: 10446045
references: Science. 2007 May 4;316(5825):732-5
references: 17478717
references: Science. 2008 Jun 6;320(5881):1320-2
references: 18535238
references: Phys Rev Lett. 1990 Mar 26;64(13):1537-1540
references: 10041423
references: Angew Chem Int Ed Engl. 2010 Nov 8;49(46):8598-601
references: 20886588
references: Science. 2003 Oct 17;302(5644):419-22
references: 14564001
references: Science. 2001 Nov 30;294(5548):1901-3
references: 11729310
references: Chem Rev. 2006 Oct;106(10):4301-20
references: 17031988
references: Nano Lett. 2006 Apr;6(4):833-8
references: 16608293
references: Acc Chem Res. 2008 Dec;41(12):1742-9
references: 18783255
references: Nano Lett. 2009 Dec;9(12):4417-23
references: 19908825
references: Phys Rev Lett. 1996 May 27;76(22):4234-4237
references: 10061235
references: Acc Chem Res. 2008 Dec;41(12):1578-86
references: 18447366
references: Nature. 2003 Oct 2;425(6957):487-90
references: 14523440
references: Phys Rev Lett. 1988 Sep 12;61(11):1321-1324
references: 10038762
references: Phys Rev Lett. 2003 Nov 28;91(22):226102
references: 14683251
references: Science. 2005 Oct 14;310(5746):291-3
references: 16224016
references: Science. 2010 Jan 15;327(5963):319-22
references: 20075249
references: Phys Rev Lett. 1992 Jun 22;68(25):3737-3740
references: 10045784
references: Phys Rev Lett. 1990 Apr 23;64(17):2090-2093
references: 10041574
references: Science. 2002 Oct 25;298(5594):811-4
references: 12399586
references: Angew Chem Int Ed Engl. 2005 Mar 29;44(14):2154-7
references: 15739241
references: J Am Chem Soc. 2008 Feb 6;130(5):1676-80
references: 18189392
references: Phys Rev Lett. 2008 Oct 3;101(14):146103
references: 18851546