【作者】 张玉微； 宋平； 陈涛； 阮明波； 徐维林；

【Author】 Yuwei Zhang;Ping Song;Tao Chen;Mingbo Ruan;Weilin Xu;Changchun Institute of Applied Chemistry;

【机构】 中国科学院长春应用化学研究所；

【摘要】 在能源催化领域,对纳米粒子活性位分布及动态变化的认识是设计催化材料,提高能源催化效率的关键。本工作利用动态光学超分辨成像技术,对纳米粒子不同位点催化过程中的荧光信号的进行跟踪,获取了Sb-TiO₂纳米棒及金三角不同位点的活性信息及时间依赖关系。通过对Sb-TiO₂纳米棒及金三角催化过程中的活性位跟踪,发现纳米粒子缺陷处具有更高的催化活性,如中间部位活性位具有低活长效性的特点,而在端点及角的位置具有高活低稳定性的特点。意外的是,部分活性位呈现出"自愈"现象,即催化位点失活后由于吸附物种的脱附重新体现出催化活性,这一发现对于指导催化剂合成具有重要意义。更多还原

【Abstract】 For the practical application of nanocatalysts it is desirable to understand the spatiotemporal fluctuations of nanocatalytic activity at the single-nanoparticle level. In this work, time-lapsed super-resolution mapping of single-molecule catalysis events on individual nanoparticles was employed to observe time-varying changes in the spatial distribution of catalysis events on Sb-doped TiO2 nanorods and Au triangle nanoplates. Compared with the active sites on well-defined surface facets, the defects of the nanoparticle catalysts possess higher intrinsic reactivity but lower stability. Corners and ends are more reactive but also less stable than flat surfaces. The super-resolution measurement of variation of different types of active catalytic sites, over both space and time, leads to a more comprehensive understanding of reactivity patterns and may enable the design of new and more productive heterogeneous catalysts.更多还原