Structural and chemical characterization of novel Ni x Zn1-x Ga2O4 nanocatalysts at atomic resolution

• Published in: Applied surface science Vol. 353; pp. 419 - 424
• Main Authors: Xu, Qian, Wu, Zhaochun, Hong, Jinhua, Chang, Xiaofeng, Li, Xueji, Yan, Shicheng, Wang, Peng
• Format: Journal Article
• Language: English
• Published: 01.10.2015
• Subjects: Atomic structure; Catalysts; Morphology; Nanostructure; Nickel; Operating temperature; Reduction; Solid solutions
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2015.06.032

Ni x Zn1-x Ga2O4 has already been demonstrated as a noteworthy example of potentially useful catalytic properties such as NO x reduction. In our previous work, it was interesting to find out that the operating temperature of NiGa2O4 catalyst in NO x reduction can be tuned by simple chemical substitution of Ni2+ by Zn2+. It is believed that the mechanism behind such stoichiometry-dependence on operating temperature should be strongly correlated with microstructure, surface morphology as well as the local composition of the nanocatalysts. In the present investigation, Ni x Zn1-x Ga2O4 solid solution was synthesized via a hydrothermal ion-exchange reaction, using NaGaO2 and the corresponding acetic salts as the starting materials. By means of a state-of-the-art aberration corrected STEM and high resolution TEM, the structural and chemical characterization at the atomic scale on the Ni x Zn1-x Ga2O4 nanocatalyst was carried out, including the crystal structure, size, morphology, surface structure and local composition. It is found that the catalyst was solid solution and most possible exposed facets may be (111).