近日,华东理工大学化学与分子工程学院工业催化研究所新引进的龚学庆教授,与美国合作者一起采用理论计算结合实验表征技术探讨了氧化物负载金属型催化剂的结构特征, 相关研究成果发表在国际化学权威杂志《美国化学会会志》上(J. Am. Chem. Soc. 130, 370 (2008))。 《美国化学会志》(Journal of the American Chemical Society, JACS)是美国化学学会的旗舰期刊,发表化学领域的所有论文。 龚学庆教授与美国Princeton University的 Annabella Selloni教授以及 Tulane University的 Ulrike Diebold教授一起,在有关负载型催化剂表面金属颗粒形貌、尺寸、位置和动力学特征的理论模拟 以及结合实验测量的结果,发现在氧化物载体-锐钛矿二氧化钛(101)表面上,负载金颗粒的尺寸较大且主要吸附在表面的台阶状缺陷上,而负载铂颗粒的尺寸 较小并均匀分布在表面各个不同的位置上。同时,表面氧空穴的存在可以显著影响金颗粒的吸附,但对铂颗粒的吸附却几乎没有影响。通过对比理论计算和实验结 果,指出金属原子在表面各处的吸附强度在很大程度上决定了金属颗粒成核及生长的热力学(结构及位置)及动力学特征。这项研究为深入理解负载型金属催化剂的 催化机理以及失活原因提供了宝贵的信息。他们的这篇研究论文 “Small Au and Pt Clusters at the Anatase TiO2(101) Surface: Behavior at Terraces, Steps, and Surface Oxygen Vacancies”日前在J. Am. Chem. Soc.上正式发表。
J. Am. Chem. Soc.,130 (1), 370 -381,
2008 . 10.1021/ja0773148
S0002-7863(07)07314-3 Web Release Date: December 11, 2007
Small Au and Pt Clusters at the Anatase TiO2(101) Surface: Behavior at Terraces, Steps, and Surface Oxygen Vacancies
Xue-Qing Gong,*Annabella Selloni,Olga Dulub,Peter Jacobson, and Ulrike Diebold*
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, and Department of Physics, Tulane University, New Orleans, Louisiana 70118
xgong@ecust.edu.cn; diebold@tulane.edu
Received September 21, 2007
Abstract:
The adsorption properties of Au and Pt metal nanoclusters on TiO2 anatase (101) were calculated using density functional theory. Structures and energetics of adsorbed Au and Pt monomers, dimers, and trimers at clean anatase TiO2(101) terraces and two major step edges, as well as O-vacancies, were systematically determined. The theoretical predictions were tested by vapor-depositing small coverages of Au and Pt on anatase (101) and investigating the resulting clusters with Scanning Tunneling Microscopy. On the clean surface, Au shows a strong tendency to form large clusters that nucleate on step edges. A preference for adsorption at type D-(112) steps is observed, which is probably a result of kinetic effects. For Pt, clusters as small as monomers are observed on the terraces, in agreement with the predicted large binding energy of 2.2 eV. Step edges play a less important role than in the case of Au. Oxygen vacancies, produced by electron irradiation, dramatically influence the growth of Au, while the nucleation behavior of Pt was found to be less affected.
迄今为止已在Nature Mat., J. Am. Chem. Soc., Phys. Rev. Lett., J. Phys. Chem. B等国际著名学术期刊上发表论文十数篇,被引用百余次。
1. Xue-Qing Gong and Annabella Selloni
Role of steps in the reactivity of the anatase TiO2(101) surface
Journal of Catalysis 249, 134-139 (2007)
2. Xue-Qing Gong, Annabella Selloni, Matthias Batzill and Ulrike Diebold Steps on anatase TiO2(101)
Nature Materials 5, 665 (2006)
3. Xue-Qing Gong, Annabella Selloni and Andrea Vittadini
Density functional theory study of formic acid adsorption on anatase TiO2(001): geometries, energetics and effects of coverage, hydration, and reconstruction
The Journal of Physical Chemistry B110, 2804 (2006)
4. Xue-Qing Gong and Annabella Selloni
Reactivity of anatase TiO2 nanoparticles: The role of the minority (001) surface
The Journal of Physical Chemistry B109, 19560 (2005)
5. Xue-Qing Gong, R. Raval and P. Hu
CHx hydrogenation on Co(0001): A density functional theory study
The Journal of Chemical Physics122, 024711 (2005)
6. Xue-Qing Gong, R. Raval and P. Hu
General insight into CO oxidation: A density functional theory study of the reaction mechanism on platinum oxides
Physical Review letters93, 106104 (2004)
7. Xue-Qing Gong, R. Raval and P. Hu
A density functional theory study on the water formation at high coverages and the water effect in the Fischer-Tropsch synthesis
Molecular Physics102, 993 (2004)
8. Xue-Qing Gong, R. Raval and P. Hu
CO dissociation and O removal on Co(0001): A density functional theory study
Surface Science562, 247 (2004)
9. E.A.P. Armstrong, R.T. Brown, M.S. Sekwale, N.C. Fletcher, X.-Q. Gong and P. Hu
The Unexpected preference for the fac-isomer with the tris(5-ester-substituted-2,2’-bipyridine) complexes of Ruthenium(II)
Inorganic Chemistry43, 1714 (2004)
10. Xue-Qing Gong, Zhi-Pan Liu, Rasmita Raval and P. Hu
A systemic study of CO oxidation on metals and metal oxides: Density functional theory calculations
Journal of the American Chemical Society 126, 8 (2004)
11. Zhi-Pan Liu, Xue-Qing Gong, Jorge Kohanoff, Cristián Sanchez and P. Hu
Catalytic role of metal oxides in gold-based catalysts: A first principles study of CO oxidation on TiO2 supported Au