Synthesis and CO Oxidation Activity of 1D Mixed Binary Oxide CeO2-LaO x Supported Gold Catalysts

Abstract

One-dimensional (1D) Ce-La nanorods with different La contents (Ce and La in the molar ratio of 1:0, 3:1, 1:1, 1:3, and 0:1) were synthesized by hydrothermal process. Au/Ce-La nanorod catalysts were obtained by a modified deposition-precipitation method. The samples were characterized by N2 adsorption-desorption (BET), ICP, X-ray diffraction (XRD), SEM, TEM, EDX, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), and temperature-programmed reduction (H2-TPR). It revealed that La existed as LaOx in the 1D nanorods. The catalysis results demonstrated that the mixed binary Ce-La nanorod oxides could be a good support for gold catalysts. The contents of La had an important influence on the catalytic performance of Au/Ce-La nanorod catalysts. Among the catalysts, when the Ce/La molar ratio was 3:1, the 1.0%Au/Ce0.75-La0.25 nanorods pretreated at 300 °C showed the best activity among the catalysts for CO oxidation, which could convert CO completely at 30 °C. The catalysts also performed high temperature resistance and good stability for CO oxidation at the reaction temperatures of 40, 70, and 200 °C.

Supported Gold Nanoparticles as Catalysts for the Oxidation of Alcohols and Alkanes

“…It was discovered also by Haruta's group in 1991 (Tsubota et al, 1991) and is still widely used (Moreau et al, 2005; Sangeetha et al, 2009; Wei et al, 2010; Tran et al, 2011; Sanada et al, 2013; Soria et al, 2014; Zahoranova et al, 2015; Zamaro et al, 2015; Pérez et al, 2016; Priecel et al, 2016; Carabineiro et al, 2017; Chen B. B. et al, 2017; Kyriakou et al, 2017; Martins et al, 2017; Rodrigues et al, 2017a,b; Vourros et al, 2017; Yu et al, 2017; Jin et al, 2018). The precursor to the active species is brought out of solution in the presence of a suspension of the support, usually by raising the pH in order to precipitate a hydroxide.…”

The Role of Gold‐Alumina Template in the Electrochemical Deposition of CeO2 Nanotubes

“…1D‐nanostructured materials based on cerium oxide (CeO 2 ) have gained notable attention owing to their wide range of applications such as in catalysis, electrocatalysis, fuel cells, solar cells, sensors, and as abrasive or polishing materials . Sol‐gel, hydrothermal, precipitation, or chemical vapor deposition (CVD) are among the examples of synthesis methods found in the bibliography that yield 1D‐nanostructured CeO 2 with improved chemical and redox properties as well as catalytic behavior . However, many of these processes involve numerous steps and/or severe working conditions like high temperatures or high pressures that render them quite complex.…”

Critical Review of Low-Temperature CO Oxidation and Hysteresis Phenomenon on Heterogeneous Catalysts

“…Recent studies focus on reducing the high cost of noble metals and improving the stability of catalysts, motivating the investigation for new materials such as Mn, Fe, Co, Ni, Cu or their combinations and concepts to reduce the use of precious metal content to find suitable substitutes for noble metals [40][41][42][43][44][45]. As the high activity, high selectivity, and long lifetime of the catalysts are a challenge in heterogeneous catalysis, it is crucial to design catalysts with active sites and other features, to render them useful for any specific applications.…”