Zhang Zhenhua, Wu Hong, Yu Zongyou, Song Rui, Qian Kun, Chen Xuanye, Tian Jie, Zhang Wenhua, Huang Weixin
Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion and Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, P. R. China.
Engineering and Materials Science Experiment Center, University of Science and Technology of China, Hefei, 230026, P. R. China.
Angew Chem Int Ed Engl. 2019 Mar 22;58(13):4276-4280. doi: 10.1002/anie.201814258. Epub 2019 Feb 6.
The identification of the contribution of different surface sites to the catalytic activity of a catalyst nanoparticle is one of the most challenging issues in the fundamental studies of heterogeneous catalysis. We herein demonstrate an effective strategy of using a series of uniform cubic Cu O nanocrystals with different sizes to identify the intrinsic activity and contributions of face and edge sites in the catalysis of CO oxidation by a combination of reaction kinetics analysis and DFT calculations. Cu O nanocrystals undergo in situ surface oxidation forming CuO thin films during CO oxidation. As the average size of the cubic Cu O nanocrystals decreases from 1029 nm to 34 nm, the dominant active sites contributing to the catalytic activity switch from face sites to edge sites. These results reveal the interplay between the intrinsic catalytic activity and the density of individual types of surface sites on a catalyst nanoparticle in determining their contributions to the catalytic activity.
确定不同表面位点对催化剂纳米颗粒催化活性的贡献，是多相催化基础研究中最具挑战性的问题之一。在此，我们展示了一种有效的策略，即使用一系列尺寸不同的均匀立方CuO纳米晶体，通过反应动力学分析和密度泛函理论（DFT）计算相结合的方法，来确定面心和棱边位点在CO氧化催化中的本征活性和贡献。在CO氧化过程中，CuO纳米晶体会发生原位表面氧化，形成CuO薄膜。随着立方CuO纳米晶体的平均尺寸从1029 nm减小到34 nm，对催化活性起主要作用的活性位点从面心位点转变为棱边位点。这些结果揭示了在决定催化剂纳米颗粒对催化活性的贡献时，本征催化活性与单个类型表面位点密度之间的相互作用。
