Formation Of Spinel Phase Research Articles

Impact of fast heating and cooling on the mechanical behaviour of alumina-magnesia refractory castables

The alumina-magnesia castables is one kind of monolithic refractories for steel ladle, whose thermo-mechanical properties vary with temperature during the lining pre-heating process and metallurgical service. The understanding of their variation tendency and sensibility to temperature fluctuation is important for the improvement of high-efficiency pre-heating strategy and real-time service performance. In this study, the influence of heat treatment temperature and heating/cooling rate on the thermo-mechanical properties and fracture behaviour of alumina-magnesia castables is investigated using uniaxial compressive tests equipped with an induction heating system and Brazilian test combined with digital image correlation and acoustic emission. The brittleness and mechanical strength of alumina-magnesia castables increase with heat treatment temperature due to the better sintering and formation of calcium hexaluminate and spinel phases. Without full relaxation of residual stresses, the stiffness increases while the strength decreases after fast heating of 200 °C/min. Meanwhile. the same castables after different thermal treatments show disparate mechanical responses to cooling rates.

Simultaneous Single Crystal Growth and Segregation of Ni-Rich Cathode Enabled by Nanoscale Phase Separation for Advanced Lithium-Ion Batteries

A novel nanoscale phase separation process has been discovered to promote the growth and segregation of single-crystal LiNi0.8Mn0.1Co0.1O2 (NMC811). This process occurs directly during high-temperature calcination without significant agglomeration. The key lies in converting transition metal hydroxide (TM(OH)2) precursors with well-controlled morphology into transition metal oxide (TMO) intermediates before reacting them with lithium salt. The nanoscale redistribution of Ni in TMO, resulting from the concurrent formation of spinel and rock salt phases, helps to deagglomerate the clusters of later-formed NMC811 crystals. The as-prepared single-crystal NMC811 is further validated in a 2Ah pouch cell, demonstrating 1,000 stable cycles. The fundamentally new reaction mechanism of single-crystal growth and segregation provides a new direction for large-scale synthesis of a broad range of single crystals for advanced energy storage.

Preparation and Properties of MgO-Al2O3-SiO2 Glass–Ceramics with Controllable Crystalline Phases

MgO–Al2O3–SiO2 (MAS) glass–ceramics with controllable crystalline phases were successfully prepared using the melting method followed by heat treatment. The effects of the main components of glass on the crystallisation kinetics, nucleation, crystallisation and properties of glass–ceramics were investigated in detail. As the Al2O3 and MgO contents increase and SiO2 content decreases, the crystallisation peak temperature and activation energy of MAS glass decrease, while the crystal growth tends to follow a homogeneous nucleation crystallisation. The MAS glass nucleation temperature and time increase with higher concentrations of Al2O3 and MgO and with a lower SiO2 concentration. Mg2(Al4Si5O18) indialite and MgAl2O4 spinel precipitate simultaneously in the MAS glass after crystallisation; the relative proportion of crystalline phases is related to the composition and crystallisation temperature. A higher SiO2 content allows the formation of a dominant indialite phase, while higher MgO and Al2O3 contents promote the formation of a dominant spinel phase. The MAS glass ceramic with a greater indialite phase has good dielectric properties with a dielectric constant of 6.499 and dielectric loss of 0.0064, while that of a higher spinel phase possesses improved mechanical properties, with a Vickers hardness of 715 Hv and a bending strength of 244.9 MPa.

Effects of chemical composition on lightweight aggregates produced from contaminated soil: Phase regulation, immobilization mechanism and leaching prediction

Contaminated soil induces serious environmental risk due to the presence of hazardous components. The preparation of lightweight aggregate (LWA) is a widely accepted technique to treat contaminated soil. This study investigated the effect of contaminated soil composition on the physical properties and immobilization of heavy metals (Cu, Cr, Pb and Ni) of LWA. Phase regulation, immobilization mechanism and leaching prediction of LWA were analyzed. Results showed that SiO2 and Al2O3 were detrimental to the bloating performance of LWA, whereas fluxing components (Fe2O3, Na2O, K2O, CaO, and MgO) are all conducive. Fluxing components can bring more liquid phase, resulting in a lower density of LWA. The addition of Fe2O3 facilitated the immobilizing Cu and Cr owing to the formation of spinel phases, such as (Mg,Cu)(Fe,Ni)2O4 and Fe(Cr,Al)2O4. Glassy phase could encapsulate heavy metals remarkably, while the high content of fluxing components was unfavorable to the immobilization of Cu and Ni. As network modifiers, Cu and Ni could participate in the formation process of glassy phase, and get encapsulated by liquid phase from fluxing components. Based on the leaching results of Cu, Cr, Pb, and Ni, leaching prediction of LWA was conducted by characteristic indexes and Riley's phase diagram. This research could guide the manufacturing process and leaching control of LWA recovered from contaminated soil.

High Mobility IZTO Thin‐Film Transistors Based on Spinel Phase Formation at Low Temperature through a Catalytic Chemical Reaction (Small Methods 7/2023)

High Mobility IZTO Thin‐Film Transistors Based on Spinel Phase Formation at Low Temperature through a Catalytic Chemical Reaction (Small Methods 7/2023)

A study on solubility of bismuth cations in nickel cobalt ferrite nanoparticles and their influence on dielectric and magnetic properties

In this work, a low temperature (∼600 °C) solution combustion technique is employed for the synthesis of Ni0.5Co0.5BixFe2-xO4 (NCBFO, where x = 0.0, 0.05, 0.1, 0.15, & 0.2) nanoparticles with crystallite size variation of 17–22 nm. The X-ray diffraction (XRD) technique is used to confirm the formation of cubic spinel phase of Bi3+ doped (for x ≤ 0.05 samples) nickel–cobalt ferrite (NCFO) nanoparticles. The increase in bismuth substitution (x > 0.05) results in the formation of the Bi2O3 along with the NCFO structure, which results in the reduction of binding energy and is confirmed by the XRD and X-ray photoelectron spectroscopy (XPS) techniques. From the Raman spectra, the change in the intensities of the peaks is observed due to the variation of Bi3+ in NCFO matrix. Due to increasing cation concentration and electronegativity, the FTIR absorption band shifts toward the lower wave numbers. Dielectric measurements were carried out to examine the charge transport behavior and electric conduction mechanism. The FESEM images shows the non-magnetic bismuth atoms are diffused into the NCFO nanoparticles. From the vibrating sample magnetometer (VSM) analysis, it is observed that saturation magnetization, remanent magnetization, coercivity and squareness ratio are found to be maximum for x = 0.15 NCBFO sample. The high coercivity (Hc = 916.8 Oe) for the x = 0.15 sample indicates the hard ferromagnetic behaviour of the samples.

Synthesis of MAl2O4(M = Mg, Co, Ni, Zn, Ba) Nanopowders by Liquid Impregnation of Nanofibrous Alumina

We report on a controlled synthesis of MAl2O4 (M = Mg, Co, Ni, Zn, Ba) nanopowders. The method includes three main steps: (i) growth of ultraporous nanofibrous Al2O3 (UPA) monoliths and their preliminary thermal treatment to remove the adsorbed and structural water, (ii) liquid-phase M-nitrate impregnation, and (iii) heat treatment allowing to form desirable nanocrystallites. Small crystallites with a spinel structure and mean size below 10 nm were obtained in Mg, Ni, and Zn aluminates after heat treatment at 500 °C. The results suggest formation of fully inverse MgAl2O4 spinels (inversion degree I ≈ 1) after the heat treatment at temperatures below 700 °C, followed by defect healing and formation of a normal spinel (I ∼ 0.3) at higher temperatures above the onset of the UPA bulk mass transport of ∼850 °C. This behavior is due to the interplay between cation diffusion and phase nucleation processes, in agreement with Ostwald’s rule. The formation of metastable spinel phases in agreement with Ostwald’s rule was confirmed after insertion of Co2+, Zn2+ (inverse spinel), and Ni2+ (normal spinel) cations. The insertion of Ba2+ cations into the UPA precursor resulted in the stuffed tridymite phase. The nanopowder synthesis route after upgrading to a large scale can contribute to the fabrication of functional materials for radiation-tolerant optics (M = Mg, Zn), catalysis (M = Ni, Co), nanophosphors (M = Ba), etc.

Conflicting roles of F doping on electrochemical performance of layered-spinel Li1.2Mn0.75Ni0.25O2-zFz as cathode materials for Li-ion batteries

Herein, the conflicting roles of F doping on the electrochemical performance of layered-spinel Li1.2Mn0.75Ni0.25O2-zFz (z = 0, 0.05, 0.1) cathode materials are studied. The compound consists of Li1.2Mn0.6Ni0.2O2 and LiMn1.5Ni0.5O4 with their phase ratio depending on F doping content. When z = 0.05, it favors the spinel phase formation, leading to increased first Coulombic efficiency and improved cycle stability. However, it reduces the cathode capacity to 250 mAh g−1 at C/10 (the capacity of the pristine is 280 mAhg−1). With F doping content increasing to z = 0.1, the cycle stability of the cathode is the best, with 96 % capacity retention after 200 cycles at C/2. The high level of F stabilizes the structure, prevents phase transition, and retards voltage decay. The result demonstrates a promising strategy for the design of composite cathode materials by F doping.

Small polaron hopping transport mechanism, dielectric relaxation and electrical conduction in NiAl2O4 electro-ceramic spinel oxide

In this study, the frequency and temperature dependent dielectric relaxation and electrical conduction mechanisms in NiAl2O4 spinel oxide ceramic have been explored in a frequency range of over a measured temperature from 163–283 K. The polycrystalline NiAl2O4 was synthesized via solid state reaction route and sintered at 1000 °C. The room temperature x-ray powder diffraction pattern confirmed the formation of NiAl2O4 spinel phase with Fd3m space group. The surface morphology of the sample was investigated by scanning electron microscopy and chemical properties by Fourier transform infrared spectroscopic analysis. Complex impedance studies revealed the presence of relaxation time distribution and charge carriers were found to be thermally activated. The Nyquist plots exhibited depressed semicircles and their fitting by an equivalent circuit model with configuration (RGCG)(RGBCGB) resolved the contributions of grains and grain-boundaries to the electrical transport properties of the material. Electrical conductivity analysis followed the Jonscher’s power law behavior and the frequency exponent suggested small polaron hopping as the governing transport mechanism in NiAl2O4 spinel oxide. Non-Debye type nature of dielectric relaxation was confirmed by the complex modulus analysis whereas dielectric constant and tangent loss analysis verified that the hopping mechanism was thermally activated.

Corrosion and degradation mechanisms of high chromia refractory bricks in an entrained-flow gasifier: experimental and numerical analysis

As a crucial component of an opposed multi-burner (OMB) coal-water slurry gasifier, severe degradation of the refractory lining frequently results in costly operation delays. In this work, the morphology and damage evolution of the used high chromia refractory bricks in a gasifier were evaluated by experimental tests and numerical analysis to gain insight into the corrosion and degradation behavior of the refractory lining. The results indicated that the degradation of high chromia refractory bricks were mainly owing to the structural spalling caused by slag corrosion and thermal stress induced by temperature gradient. The stress cracks developed at the corroded interface provided a penetration pathway for slag and served as a sub-surface for further corrosion, resulting in additional corrosion and spalling. Furthermore, the formation of the composite spinel phase with a high thermal expansion coefficient also contributed to significant thermomechanical stress. The degradation behavior of high chromia refractory brick followed the “penetration-dissolution/reaction-spalling” mechanism. Based on experimental and numerical results, a conceptual model was developed to describe the progressive degradation mechanism of refractory, and several possible solutions were also suggested.

Low-temperature gas-phase toluene catalytic combustion over modified CoCr2O4 spinel catalysts: Effect of Co/Cr content and calcination temperature

Un-supported spinel-type cobalt chromite catalysts were synthetized by propionic acid-mediated sol-gel method and tested for toluene oxidation. The influence of the Co and Cr content and the preparation conditions on physico-chemical, surface and catalytic properties for this reaction has been for the first time evaluated. Co-rich CoCr2O4 was the most active catalyst, likely due to the formation of a single CoCr2O4 spinel phase, a favorable surface composition and higher low-temperature reducibility. Besides, the increase of the calcination temperature, despite worsening textural properties, also has a promoting effect on the catalytic activity by preserving a suitable reducibility and further enhancing the surface properties. Surface Cr6+ ions and adsorbed oxygens (Oads), which are more abundant in the most efficient catalyst (Co-rich catalyst calcined at 685 °C), seem to play an important role on toluene oxidation reaction. These findings may open potential strategies in the development of efficient and economically competitive catalysts for elimination of VOCs like toluene.

Modulating the bactericidal activity and corrosion resistance of Al2O3 porous ceramics through Cu and Fe co-introduction for membrane support application

Ceramic membrane-based filtration is perceived as an energy-saving and chemical-less solution to the wastewater problem. In this work, Cu- and/or Fe-containing Al2O3 porous ceramics were fabricated by powder metallurgy, with Cu and Fe introduction for bactericidal functionalization and Cu stabilization, respectively. The Cu- and Fe-free Al2O3 porous ceramics were composed of irregular α- Al2O3 particles and inter-particle NaAlSiO4 phase. The introduction of Cu resulted in the formation of band-shaped CuO and particle-shaped CuAl2O4 spinel phase in Al2O3 matrix. Further introducing Fe into Cu-containing Al2O3 increased the fraction of particle-shaped CuM2O4 (M=Al/Fe) spinel phase, while decreased that of band-shaped CuO. Without Cu incorporation, Fe reacted with Al2O3 to form Al3Fe5O12 phase. The introduction of Cu resulted in increased linear shrinkage and bending strength, while decreased porosity of Al2O3 porous ceramics. However, the effects of Fe were the opposite. The Cu-containing Al2O3 ceramics exhibited excellent bactericidal activity, but poor acidic corrosion resistance. The co-introduction of Cu and Fe enhanced the acidic corrosion resistance due to Cu stabilization from CuO to spinel phase, while compromised the bactericidal activity to some extent. Together, the results indicate that Cu- and Fe-containing Al2O3 porous ceramics are promising candidate materials for ceramic membrane support application.

High Mobility IZTO Thin-Film Transistors Based on Spinel Phase Formation at Low Temperature through a Catalytic Chemical Reaction.

In this paper, In0.22 Znδ Sn0.78- δ O1.89- δ (δ = 0.55) films with a single spinel phase are successfully grown at the low temperature of 300 °C through careful cation composition design and a catalytic chemical reaction. Thin-film transistors (TFTs) with amorphous In0 .22 Znδ Sn0.78- δ O1.89- δ (δ = 0.55) channel layers have a reasonable mobility of 41.0 cm2 V-1 s-1 due to the synergic intercalation of In and Sn ions. In contrast, TFTs with polycrystalline spinel In0 .22 Znδ Sn0.78- δ O1.89- δ (δ = 0.55) channel layers, achieved through a metal-induced crystallization at 300 °C, exhibit a remarkably high field-effect mobility of ≈83.2 cm2 V-1 s-1 and excellent stability against external gate bias stress, which is attributed to the uniform formation of the highly ordered spinel phase. The relationships between cation composition, microstructure, and performance for the In2 O3 -ZnO-SnO2 ternary component system are investigated rigorously to attain in-depth understanding of the roles of various crystalline phases, including spinel Zn2- y Sn1- y In2 y O4 (y = 0.45), bixbyite In2-2 x Znx Inx O4 (x = 0.4), rutile SnO2 , and a homologous compound of compound (ZnO)k (In2 O3 ) (k = 5). This work concludes that the cubic spinel phase of Zn2- y Sn1- y In2 y O4 (y = 0.45) film is a strong contender as a substitute for semiconducting polysilicon as a backplane channel ingredient for mobile active-matrix organic light-emitting diode displays.

Structural, magnetic and antibacterial studies of gadolinium doped cobalt ferrite nanoparticles synthesized at low temperature

In this work structural, magnetic and antimicrobial studies of gadolinium (Gd) doped cobalt ferrite nanopowder samples were synthesised through facile auto-combustion route using citric acid as combustion agent. The pristine nanopowders were sintered at 600 °C. X-ray diffraction (XRD), infrared spectroscopy (IR) measurements indicated the formation of a single spinel phase. The lattice constant gradually increased from 8.3801 Å to 8.3915 Å with increasing Gd concentration. The average crystallite size varied from 54 nm to 42.7 nm. The correlation between the cation distribution from XRD and the magnetic properties is discussed. The substitution of Gd ions significantly reduced the magnetisation from 60.6 to 36.6 emu g−1 and increased the coercivity. Antimicrobial activities of pure and Gd substituted cobalt ferrite are carried out against Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and also against fungi strain (Aspergillus niger) pathogens, suggesting that Gd substitution significantly improves the activity of cobalt ferrite nanopowders.

The Effect of Opto-Electronic Transition Type on the Electric Resistivity of Cr-Doped Co3O4 Thin Films

Cr-doped Co3O4 thin films were prepared by spray pyrolysis on soda-lima glass. The structure and morphology of the prepared samples were characterized by grazing incidence X-ray diffraction (GIXRD), Fourier-transform infrared spectroscopy (FTIR) and Scanning electron Microscopy (SEM). The results indicated the formation of a single cubic spinel phase with a crystallite size of about 6 nm. Different electronic transitions and estimations of the band gap structure were determined from the optical absorption spectra. The dependence of electrical resistivity on Cr content was investigated. It was found that the resistivity increased by increasing the Cr content. In addition, the effect of photon excitation on the electrical properties showed that the electrical resistivity decreased under visible illumination (λvis. = 532 nm) and increased under infrared illumination (λIR = 780 nm). The relative change in resistivity (sensitivity) under both light illuminations was enhanced by increasing the Cr content. Therefore, this work introduces a new application for Co3O4 material as a light detector.

Stabilizing High‐Nickel Cathodes with High‐Voltage Electrolytes

AbstractElectrolytes connect the two electrodes in a lithium battery by providing Li+ transport channels between them. Advanced electrolytes are being explored with high‐nickel cathodes and the lithium‐metal anode to meet the high energy density and cycle life goals, but the origin of the performance differences with different electrolytes is not fully understood. Here, the mechanisms involved in protecting the high‐capacity, cobalt‐free cathode LiNiO2 with a model high‐voltage electrolyte (HVE) are delineated. The kinetic barrier posed by a thick surface degradation layer with poor Li+‐ion transport is found to be the major contributor to the fast capacity fade of LiNiO2 with the conventional carbonate electrolyte. In contrast, HVE reduces the side reactions between the electrolyte and the electrodes, leading to a thinner nano‐interphase layer comprised of more beneficial species. Crucially, the HVE leads to a different surface reorganization pathway involving the formation of a thinner nanoscale LiNi2O4 spinel phase on the LiNiO2 surface. With a high 3D Li+‐ion and electronic conductivity, the spinel LiNi2O4 reorganization nanolayer preserves fast Li+ transport across the cathode–electrolyte interface, reduces reaction heterogeneity in the electrode and alleviates intergranular cracking within secondary particles, resulting in superior long‐term cycle life.

Efficient and stable Ni-supported novel porous Ca-Mg-Al complex oxide catalyst for catalytic pyrolysis of oleic acid into gasoline-kerosene rich production using methanol as a hydrogen donor: Synthesis methods and process optimization

In this study, a series of cost-effective and eco-friendly Ca-Mg-Al and Ni-modified Ca-Mg-Al catalysts were successfully synthesized with different methods (coprecipitation, impregnation and mechanical mixing method) and applied to catalytic pyrolysis vapor upgrading of oleic acid (OA) to produce gasoline-kerosene rich production using methanol as a hydrogen donor. In addition, the effects of the process parameters (catalyst type, OA to methanol ratio, pyrolysis/catalytic temperature, catalyst loading, feedstock injection volume) on the product yield and selectivity were explored, and the reuse properties and deactivation mechanism were also evaluated. Active Ni species coupled with methanol were more conducive to enhancing the catalyst activity and OA conversion and obviously increased the selectivity toward the gasoline-kerosene product. The impregnation method was favorable for the formation of NiAl2O4 species, and coprecipitation method suppressed the formation of NiAl2O4 species. The enhanced activity and deoxygenation selectivity of the coprecipitation method (NiCaMgAl) at lower pyrolysis temperatures was attributed to the abundant higher specific surface area and pore size, higher active metal oxide (Ni2+) and well-active Ni dispersion with a smaller particle size, as well as the lower acidity and partially oxidized Ni, which suppressed the NiAl2O4 spinel phase formation compared with the Ni/Ca-Mg/Al (impregnation) and Ca-Mg-Al (mixing) catalysts, which was beneficial to the decarbonylation/ decarboxylation reaction and inhibited the hydrocracking reaction of CC. Therefore, 100% conversion, 97.12% hydrocarbon yield, 54.53% gasoline and 58.80% kerosene content over NiCaMgAl catalyst were obtained under optimal conditions (pyrolysis/catalytic temperature = 450/500°C, catalyst loading = 1.5 g, feedstock injection volume = 0.1 ml/min and OA to methanol ratio = 3:1). Moreover, NiCaMgAl catalyst also demonstrated good reusability and hydrothermal stability performance due to the lower amount of coke deposition with a lower graphitized structure, which suppressed sintering.

Correlation between Cation Distribution and Magnetic and Dielectric Properties of Dy3+-Substituted Fe-Rich Cobalt Ferrite.

Designing electromagnetic materials, particularly those based on transition-metal-containing spinel ferrites, with a controlled structure, phase, and chemistry at the nanoscale dimensions while realizing enhanced electrical and magnetic properties continues to be a challenging problem. Herein, we report on the synthesis and structure-property correlation of dysprosium (Dy)-substituted iron-rich cobalt ferrite (Co0.8Fe2.2-xDyxO4; CFDO; x = 0.000-0.100) oxides with variable Dy3+ concentration. Chemical bonding analyses of CFDO nanomaterials using Raman spectroscopic analyses supported the spinel phase formation with high quality. Cation distribution determined from Mössbauer spectroscopy reveals the fact that Dy3+ occupies the octahedral site of the spinel lattice. Saturation magnetization (Ms) values calculated using Neel's two-sublattice model and cation distribution derived from Mossbauer's studies correlate well with the magnetization values obtained from SQUID measurements. The B-site hyperfine field decreases from 52.24 ± 0.10 to 49.26 ± 0.00 T, as evidenced by the Mössbauer spectra, with Dy substitution, which decreases the Fe-ion occupancy from the octahedral site of CFDO. Frequency-dependent dielectric constant indicates electron hopping in the grain interior, which ceases above 6.3 kHz. Dielectric measurements indicate that these CFDO compounds are useful for absorption at higher frequencies. Thus, using the combined approach based on Raman and Mössbauer spectroscopic analyses, the present work elucidates the structure, chemical bonding, and magnetic properties of Dy-substituted Fe-rich cobalt ferrite. CFDO may serve as a model system to apply to a class of Fe-rich ferromagnetic nanomaterials for electromagnetic and sensor applications.

Mechanism of in-situ formation of spinel and its effect on the mechanical properties of Al2O3–C refractories

This work looked at the in-situ formation mechanism of magnesia alumina spinel in Al2O3–C refractories with magnesia addition at different firing temperatures. A comprehensive study on the mechanical properties of Al2O3–C refractories was performed in comparison to traditional analogs. The magnesia alumina spinel was in-situ formed at the firing temperature of 1150 °C in Al2O3–C refractories. With the increase of the firing temperature, the Al2O3 phase was gradually dissolved in spinel phase to form aluminum rich spinel phase, resulting in a decrease in its lattice constant due to the defects formation. The formed spinel phase was homogenously distributed and bonded well with corundum, improving the interfacial bond, load transferring capacity and crack propagation resistance. The formation of spinel phase also enhanced the sintering of the alumina matrix owing to the solid solution of alumina in the spinel. Therefore, the mechanical properties such as cold modulus of rupture and hot modulus of rupture in Al2O3–C refractories achieved a substantial enhancement compared with traditional refractories.

CO preferential oxidation in H2-rich stream over the CuO-MnOx mixed oxide catalysts prepared by a facile mechanochemical preparation method

The CuMn samples with various CuO weight percentages were synthesized by the mechanochemical route. The catalytic activity of the prepared samples was determined in the preferential oxidation of CO process (CO-PROX) in the temperature range of 40–250 °C. According to the XRD results, the 5CuMn and 10CuMn samples exhibited the spinel phase in their structures. The spinel phase formation enhanced the CO adsorption active sites and modified the redox properties. The results indicated that the copper incorporation into the manganese oxide modified the catalytic activity and structural properties. The 5CuMn catalyst with the highest BET area (72.1 m2 g−1) possessed 96% CO conversion and 50% CO2 selectivity at 70 °C (GHSV = 30,000 ml/h.gcat) and significant resistance in the presence of water due to the formation of hydroxyl groups over the catalyst surface. The catalyst activity remained stable for 14 h at 130 °C. Furthermore, the influence of calcination temperature, feed composition, and GHSV value on the catalytic performance of the 5CuMn catalyst was studied.