A Comparative Study of Supported and Bulk Cu–Mn–Ce Composite Oxide Catalysts for Low-Temperature CO Oxidation

In situfabrication of Cu-Mn-O nanostructure catalysts on Ti mesh and their catalytic property optimization for low-temperature and stable CO oxidation

A series of interlaced 'tripe-shaped' nanoflake catalysts made of CuMn2O4werein situprepared on Ti mesh substrate through the associated methods of plasma electrolyte oxidation and hydrothermal technique. The surface morphology, elemental distribution and chemical state, phase composition and microstructure of CuMn2O4nanostructures prepared under different conditions were systemically investigated. To evaluate the catalytic activity, the CO oxidation as a probe reaction was used, and the results showed that 12h-Cu1Mn2-300 (hydrothermal reaction at 150 °C for 12 h, Cu/Mn = 1/2 in initial precursor, heat treatment temperature at 300 °C) exhibited the best CO oxidation capability withT100= 150 °C owe to the formation of uniform CuMn2O4nanosheet layersin situgrown on flexible Ti mesh and the synergistic effect of Cu and Mn species in spinel CuMn2O4, which makes it more active towards CO oxidation than pure copper/manganese oxides.

Cu-Mn-Ce ternary oxide catalyst coupled with KOH sorbent for air pollution control in confined space

For air pollution control in confined space such as submarine and spacecraft, copper-manganese-cerium ternary oxide catalysts coupled with KOH sorbent were synthesized through the wet impregnation method, solid-state impregnation method A and B, and wet/solid-state impregnation method. The samples were tested for CO and CO₂ removal dynamically and isothermally from 30 °C to 150 °C using two fixed bed reactors, and then characterized by XRD, nitrogen adsorption and desorption, and FE-SEM/EDS. The results showed that all the coupled CuMnCe/KOHs were able to catalyze CO and capture the produced CO₂ in situ. While the coupling treatments affected the CO oxidation and CO₂ absorption performance of the samples significantly and differently. Among all samples, CuMnCe/KOH-WSI with the large KOH bulk phase exhibited the outstanding CO catalytic activity and CO₂ sorption efficiency, higher than the uncoupled CuMnCe/KOH. While for CuMnCe/KOH-WI and CuMnCe/KOH-SI-I samples demonstrating high-dispersed KOH species in the catalyst, the addition of the sorbent could inhibit the catalyst activity due to the occupation of the surface site and pore structure. Furtherly, the effect of the temperature was varied for CO conversion and CO₂ capture performances of the sample, while they achieved an optimization balance at 150 °C for CuMnCe/KOH-WSI.