Visible-light-enhanced catalytic oxidation reactions on plasmonic silver nanostructures
Visible-light-enhanced catalytic oxidation reactions on plasmonic silver nanostructures
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DOI：
10.1038/nchem.1032
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发表时间：
2011-06-01
期刊：
影响因子：
21.8
通讯作者：
Linic, Suljo
中科院分区：
文献类型：
--
作者：
Christopher, Phillip;Xin, Hongliang;Linic, Suljo
催化在化学转化、能源生产和污染缓解中起着关键作用。与限速基本步骤相关的高活化势垒要求大多数商业非均相催化反应在相对高的温度下进行，这损害了能量效率和催化剂的长期稳定性。在这里，我们表明，银的等离子体纳米结构可以同时使用低强度可见光（大约为太阳强度）和热能来驱动催化氧化反应，例如乙烯环氧化、CO氧化和NH3氧化-温度低于仅使用热刺激的传统同行。基于动力学同位素实验和密度泛函计算，我们假设激发等离子体激元的银表面的行为，以填充O-2反键轨道，从而形成一个短暂的负离子状态，从而促进限速O-2-解离反应。这些结果可以帮助设计比当前工艺更节能和更鲁棒的催化工艺。
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 O-2 antibonding orbitals and so form a transient negative-ion state, which thereby facilitates the rate-limiting O-2-dissociation reaction. The results could assist the design of catalytic processes that are more energy efficient and robust than current processes.