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.
- Publication:
-
Nature Chemistry
- Pub Date:
- June 2011
- DOI:
- 10.1038/nchem.1032
- Bibcode:
- 2011NatCh...3..467C