Elucidating the Roles of Local and Nonlocal Rate Enhancement Mechanisms in Plasmonic Catalysis
Elucidating the Roles of Local and Nonlocal Rate Enhancement Mechanisms in Plasmonic Catalysis
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DOI：
10.1021/jacs.2c08561
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发表时间：
2022-10-24
影响因子：
15
通讯作者：
Linic, Suljo
中科院分区：
文献类型：
--
作者：
Elias, Rachel C.;Linic, Suljo
等离子体金属纳米颗粒（例如，Ag、Au和Cu）构成了一类经由局部表面等离子体共振（LSPR）的激发与光相互作用的材料。许多研究已经报道了与不存在照射的相应系统相比，照射的等离子体纳米颗粒催化剂上的化学反应速率的显著增强。已经提出了两种机制来解释LSPR诱导的化学反应性。一种机制假设局部等离子体激元诱导的热电荷载流子介导的反应物的活化，而另一种机制假设LSPR诱导的催化剂的平衡加热，这导致能量转移到吸附的反应物和化学反应。在这方面的贡献，我们开发了一种装置，适合准确的原位催化剂温度和动力学反应速率测量。我们采用这种设置来研究LSPR诱导的速率增强的情况下，CO氧化反应的等离子体，monoclonal Ag纳米粒子催化剂上的α-Al 2 O 3的支持研究。我们探讨了各种Ag负载和聚类水平。我们的数据表明，平衡加热的催化剂不能完全解释照明诱导的等离子体速率增强。即使对于Ag纳米颗粒的高负载和聚集，也是这种情况，其中平衡加热显著增加。基于分析，我们提出，局部效应，相关的等离子体诱导的活化吸附物（反应物）通过电子激发的反应物或光热加热的反应物，是高度本地化的个别纳米粒子，在驱动LSPR诱导的化学反应中发挥了关键作用。
Plasmonic metal nanoparticles (e.g., Ag, Au, and Cu) constitute a class of materials that interact with light via the excitation of localized surface plasmon resonance (LSPR). Numerous studies have reported substantial enhancements in the rates of chemical reactions on illuminated plasmonic nanoparticle catalysts compared to corresponding systems in the absence of illumination. There are two mechanisms that have been proposed to explain the LSPR-induced chemical reactivity. One mechanism assumes a local plasmon-induced hot charge-carrier-mediated activation of the reactants, while the other assumes an LSPRinduced equilibrium heating of the catalyst, which leads to energy transfer to and chemical reaction of the adsorbed reactants. In this contribution, we developed a setup amenable to accurate in situ catalyst temperature and kinetic reaction rate measurements. We employed this setup to study the LSPR-induced rate enhancement in a case study of the CO oxidation reaction on plasmonic, monometallic Ag nanoparticle catalysts supported on alpha-Al2O3. We explored various Ag loadings and clustering levels. Our data show that the equilibrium heating of the catalyst cannot fully explain the illumination-induced plasmonic rate enhancements. This is the case even for high loading and clustering of Ag nanoparticles, where the equilibrium heating significantly increases. Based on the analysis, we propose that local effects, related to the plasmon-induced activation of adsorbates (reactants) via electronic excitation of the reactant or photothermal heating of the reactants that is highly localized to the individual nanoparticles, play a critical role in driving LSPR-induced chemical reactions.