Enhancing CO Oxidation Activity via Tuning a Charge Transfer Between Gold Nanoparticles and Supports
Enhancing CO Oxidation Activity via Tuning a Charge Transfer Between Gold Nanoparticles and Supports
复制标题
DOI：
10.1021/acs.jpcc.1c10072
复制
发表时间：
2022-03
期刊：
影响因子：
--
通讯作者：
Hao-Hsun Yang;J. Cen;Qiyuan Wu;C. Ridge;X. Tong;Chenyu Zhou;V. Veerasamy;D. Su;C. M. Lindsay;Mingzhao Liu;A. Orlov
中科院分区：
文献类型：
--
作者：
Hao-Hsun Yang;J. Cen;Qiyuan Wu;C. Ridge;X. Tong;Chenyu Zhou;V. Veerasamy;D. Su;C. M. Lindsay;Mingzhao Liu;A. Orlov
负载型纳米粒子的界面电荷转移是决定其催化性能的关键因素之一。在这项工作中，我们表明，在一个系统的方式，从半导体载体的电荷转移到Au纳米粒子催化剂可以降低对CO氧化的起始温度。为了控制界面电荷转移的大小，采用氦滴沉积法制备了一种新型的Au/SiO2/Si复合体系，该体系具有精确调节的SiO2层厚度.在X射线光电子能谱和数值模拟的支持下，证实了在Au/SiO2/Si异质结上形成的肖特基势垒导致了负电荷在Au纳米颗粒表面的积累。反过来，这种额外的电荷可以转移到吸附的O2分子的反键轨道，以激活O-O键，导致增强CO氧化。除了电荷转移机制，一个强大的电场所产生的肖特基势垒的形成的作用也进行了探讨，以解释所观察到的催化反应性的增强。总的来说，这项工作突出了系统地调整金属-载体相互作用以加速催化反应和设计下一代纳米催化剂的重要途径。
Charge transfer from the supports to nanoparticles at the interface is one of the key factors to determine the catalytic performances of supported nanoparticles. In this work, we showed in a systematic way that the charge transfer from semiconductor supports to Au nanoparticle catalysts can lower the onset temperature toward CO oxidation. For this study, a novel Au/SiO2/Si composite system synthesized by the helium droplet deposition method with precisely tuned SiO2layer thickness was fabricated to control the magnitude of interfacial charge transfer. With the support of X-ray photoelectron spectroscopy and numerical simulations, it was demonstrated that the Schottky barrier formed across the Au/SiO2/Si heterojunction led to a negative charge accumulation on the surface of Au nanoparticles. In turn, this additional charge can be transferred to the antibonding orbital of adsorbed O2molecules to activate the O–O bonds, leading to enhanced CO oxidation. In addition to the charge transfer mechanism, the role of a strong electric field arising from the formation of the Schottky barrier was also explored to explain the observed enhancement of catalytic reactivity. Overall, this work highlights an important pathway for systematically tuning metal–support interactions to accelerate catalytic reactions and designing the next generation of nanocatalysts.