Mn Ion substituted CeO₂Nano spheres for Low Temperature CO Oxidation: The Promoting Effect of Mn Ions

Abstract

A series of Ce1‐xMnxO2‐δ (x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5) nanocatalysts were prepared by solution combustion synthesis. XRD results confirmed the absence of bulk manganese oxide in Ce1‐xMnxO2‐δ indicating the substitution of Mn ion in ceria matrix. The percentage C and N doping in Ce1‐xMnxO2‐δ was quantified with a CHN analyzer, whereas, the mesoporous nature of the catalysts was confirmed by N2 physisorption analysis. Raman, H2‐TPR results confirmed the increasing oxygen vacancies on Mn substitution, whereas, UV‐VIS DRS and XPS confirmed the multiple oxidation states of Mn ion. SEM and TEM analysis highlighted the near spherical morphology and nanoparticle size, respectively. The rate of CO oxidation was found to be the highest for Ce1‐xMnxO2‐δ (x=0.2), which was assigned due to the combined effect of highest amount of Mn+2 and/or due to the highest oxygen vacancies.

Co-Supported CeO2Nanoparticles for CO Catalytic Oxidation: Effects of Different Synthesis Methods on Catalytic Performance

“…Chen et al [28] synthesized Co 3 O 4 -CeO 2 core-shell catalysts and proved that the synergistic effect between Co 3 O 4 and CeO 2 is responsible for their enhanced catalytic activity compared with that of regular catalysts. Narayana et al [29] prepared spherical CeO 2 nanoparticles with Mn-ion substitution and observed the highest CO oxidation rate for the structure with the highest amounts of Mn 2+ as well as oxygen vacancies. Obviously, nanoscale catalysts exhibit excellent catalytic performances due to the size effect and their special morphology.…”

The Synthesis of SiO2@AuAg@CeO2 Sandwich Structures with Enhanced Catalytic Performance Towards CO Oxidation

“…In addition, the presence of Ag facilitates the stability of the gold supported catalysts . (iii) The CeO 2 shell, which is with excellent redox properties and oxygen storage capability, facilitates the CO oxidation process . Moreover, the efficiency of CeO 2 to provide oxygen is greatly raised in the presence of silver even at high temperatures, which further improve the catalytic activity of the SACs in CO oxidation …”

Low temperature CO oxidation by doped cerium oxide electrospun fibers

“…However, it is still possible that we have small Mn x O y islands on the ceria surface and they are active like Co 3 O 4 providing additional active sites. For manganese, this high doping level was previously proven to be effective for CO oxidation [50].…”