Bi-active sites of stable and highly dispersed platinum and oxygen vacancy constructed by reducing a loaded perovskite-type oxide for CO oxidation

• Published in: Applied surface science Vol. 532; p. 147455
• Main Authors: Zhang, Siran, An, Kang, Li, Shuangshuang, Zhang, Ziyang, Sun, Ruolin, Liu, Yuan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2020
• Subjects: Bi-active sites; Carbon monoxide oxidation; Oxygen vacancy; Perovskite-type oxide; Platinum cluster; Platinum cluster; Carbon monoxide oxidation; Bi-active sites; Perovskite-type oxide; Oxygen vacancy
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.147455

Schematic illustration of the structural evolution of Pt/LaCoxNi1−xO3/SiO2 from LaCoxNi0.87−xPt0.13O3/SiO2. [Display omitted] •A facile method for constructing stable and highly dispersed bi-active catalytic sites were proposed.•Pt clusters and oxygen vacancies could be constructed.•Pt/LaCoxNi1−xO3 loaded on SiO2 was obtained by using a perovskite-type oxide as the precursor.•The catalyst showed excellent activity and stability for CO oxidation. A new scheme for constructing bi-active sites of highly dispersed Pt and oxygen vacancies on a catalyst was put forward in this study. Pt/LaCoxNi1−xO3/SiO2 was synthesized by reducing LaCoxNi0.87−xPt0.13O3 with the structure of perovskite loaded on silica. The catalytic performance for carbon monoxide oxidation over the catalysts were studied. The catalysts were characterized via using XRD, XPS, XAFS, N2 adsorption–desorption, H2-TPR, TEM, O2 and CO-TPD techniques. The results pointed out that nanocrystal lines of LaCoxNi0.87−xPt0.13O3 were supported on SiO2. Pt clusters could be formed through reduction process at 300 °C and highly dispersed on catalyst’s surface, and the catalyst transformed to Pt/LaCoxNi1−xO3/SiO2; at the same time, oxygen vacancies also formed on the surface of LaCoxNi1−xO3. The catalytic test revealed that LaCo0.44Ni0.43Pt0.13O3/SiO2 displayed high activity and good stability for the oxidation of CO. The highly dispersed closely contact bi-active sites, the confinement of oxygen vacancies and strong interaction between Pt clusters and support were responsible for the significant catalytic activity and stability of LaCo0.44Ni0.43Pt0.13O3/SiO2 catalyst.