The Formation of Mn-Ce Oxide Catalysts for CO Oxidation by Oxalate Route: The Role of Manganese Content

Abstract

The Mn-Ce oxide catalysts active in the oxidation of CO were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), transition electron microscopy (TEM), energy dispersive X-Ray (EDX), and a differential dissolution technique. The Mn-Ce catalysts were prepared by thermal decomposition of oxalates by varying the Mn:Ce ratio. The nanocrystalline oxides with a fluorite structure and particle sizes of 4–6 nm were formed. The introduction of manganese led to a reduction of the oxide particle size, a decrease in the surface area, and the formation of a MnyCe1−yO2−δ solid solution. An increase in the manganese content resulted in the formation of manganese oxides such as Mn2O3, Mn3O4, and Mn5O8. The catalytic activity as a function of the manganese content had a volcano-like shape. The best catalytic performance was exhibited by the catalyst containing ca. 50 at.% Mn due to the high specific surface area, the formation of the solid solution, and the maximum content of the solid solution.

Separation of nickel from cobalt and manganese in lithium ion batteries using deep eutectic solvents

“…These mixed oxalates can either be used as a feedstock for LIB manufacture via high temperature processing with the requisite nickel and lithium complexes in the desired ratios or converted to mixed Mn/Co oxides for use in alkaline fuel cell catalysts. [61][62][63][64] We therefore propose the following flowsheet (Fig. 5) for processing cathode black mass from LIBs.…”

Fabrication of high-performance CeO2–MnOx/TiO2/Ti monolithic catalysts for low-temperature and stable CO oxidation

“…28 Therefore, this strong interaction between MnO x and CeO 2 can provide a highly active surface, which is instrumental in the CO catalytic oxidation process. 29 The morphology, size and density of the MnO x nanostructures were regulated by controlling the deposition time and the urea concentration. Fig.…”

“…One can see that the CO oxidation performance of the CeO 2 -MnO x / TiO 2 /Ti nanosheet catalysts is remarkably enhanced compared to the CeO 2 -MnO x based catalysts reported in the literature, as listed in Table 2. 18,29,37,45,49,50 The catalytic stability as an important part of evaluating the general performance of the synthesized catalysts was investigated at their T 100 under the same feeding gas, and the results are shown in Fig. 7c.…”

The Study of Thermal Stability of Mn-Zr-Ce, Mn-Ce and Mn-Zr Oxide Catalysts for CO Oxidation

“…MnO x -CeO 2 are the most catalytically active manganese-containing oxides [ 18 ]. The incorporation of manganese cations into the ceria lattice with the formation of solid solution causes a decrease in crystallinity, creating more lattice defects and oxygen vacancies, which significantly improves the ability of CeO 2 to accumulate oxygen, and also increases the mobility of oxygen on its surface [ 19 ]. However, MnO x -CeO 2 has low thermal stability.…”