Bi-active sites of stable and highly dispersed platinum and oxygen vacancy constructed by reducing a loaded perovskite-type oxide 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/LaCo x Ni 1−x O 3 /SiO 2 was synthesized by reducing LaCo x Ni 0.87−x Pt 0.13 O 3 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, N 2 adsorption–desorption, H 2 -TPR, TEM, O 2 and CO-TPD techniques. The results pointed out that nanocrystal lines of LaCo x Ni 0.87−x Pt 0.13 O 3 were supported on SiO 2 . Pt clusters could be formed through reduction process at 300 °C and highly dispersed on catalyst’s surface, and the catalyst transformed to Pt/LaCo x Ni 1−x O 3 /SiO 2 ; at the same time, oxygen vacancies also formed on the surface of LaCo x Ni 1−x O 3 . The catalytic test revealed that LaCo 0.44 Ni 0.43 Pt 0.13 O 3 /SiO 2 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 LaCo 0.44 Ni 0.43 Pt 0.13 O 3 /SiO 2 catalyst.