Structure–activity relation of spinel-type Co–Fe oxides for low-temperature CO oxidation

Non-noble, efficient catalyst of unsupported α-Cr2O3 nanoparticles for low temperature CO Oxidation

“…The reaction mixture consisted of 1 vol.% CO, 1.25 vol.% O 2 and 50 vol.% H 2 in He20094 36 Co 0.9 Fe 2.1 O 4 20 mg catalyst were used. The reaction gas mixture consisted of 1% CO and 10% O 2 in argon with a total flow rate of 15 mL/min235205 37 α-Fe 2 O 3 20 mg of the catalyst. The total flow rate was 15 ml min −1 with 1% of CO and 10% O 2 385325 38 Co/CeO 2 Catalyst dose: 250–300 mg CO + O 2 with a 1:3 mass ratio200150 39 …”

Preferentially Oriented Nanometer-Sized CoFe2O4 Mesocrystals Embedded in the BiFeO3 Matrix for Opto-Magnetic Device Applications

“…Figure (a) shows that Bi 4f core-level spectra exhibit peaks attributable to Bi 3+ 4f 5/2 and 4f 7/2 states, suggesting the phase purity of the BFO phase. , The core-level spectra of Co 2p are displayed in Figure (b), which can be deconvoluted into peaks corresponding to Co 2p 1/2 and 2p 3/2 states, indicating the Co 2+ oxidation state, respectively, existing in octahedral and tetrahedral sites . However, it is noted that while a broad satellite peak originating from Co 2+ can evidently be identified, ,,, the peak intensity is vastly different for samples grown on STO and LAO substrates. Since the satellite peak intensity has been delineated to be highly dependent on the geometry of the crystal structure, the result clearly indicates that different defects might exist in the lattice of the respective films.…”

“…CoFe 2 O 4 (CFO) is a unique member of the magnetic ferrites having a wide variety of interesting properties, such as large magnetic anisotropy, a large coercive field, a large magnetostriction coefficient, moderate saturation magnetization, superparamagnetism, tunable photomagnetism, and an optical band gap in the visible light region, making it a versatile candidate for numerous potential applications. − For instance, the superparamagnetism and highly active catalytic performance exhibited in crystalline CFO nanoparticles have promised their unique application potentials in medical and environmental emission control, respectively. In particular, the physical properties of the CFO nanoparticles can be further modified and controlled by their sizes, shapes, and chemical compositions. − CFO nanoparticles could also be combined with other materials as nanocomposites having core–shell structures to enhance their functionality . On the other hand, the CFO thin films have also exhibited a broad range of magnetic, optical, and electrical properties suitable for integrating a wide variety of spintronic and opto-magnetic devices. − Perhaps one of the advantages of CFO thin films is their physical property tunability via strain engineering by choosing appropriate substrates and controlling the growth parameters.…”

Preferential Oxidation of CO over CoFe2O4 and M/CoFe2O4 (M = Ce, Co, Cu or Zr) Catalysts

“…The cobalt ferrite (CoFe 2 O 4 ) presents the inverse (or partially inverse) spinel structure in which an important part of the Co 2+ cations are located in the octahedral sites and corresponding part of Fe 3+ cations are tetrahedrally coordinated [11,12]. Such structure is proposed to provide a good level of CO oxidation activity to the ferrite, attributed to the formation of very active octahedral Co 3+ upon oxidation under the reactant stream [9], with respect to other analogous cobalt spinel formulations with the normal spinel structure [9,10,[13][14][15][16]. Few reports in the literature have studied cobalt ferrite-based catalysts for the CO-PROX process [17,18].…”