Brunauer – Emmer – Teller Research Articles

Synthesis and characterization of AlxCu0.7Mn0.3Fe2-xO4 ferrite and its application in adsorption of dyes

The increasing presence of artificial dyes in industrial wastewater has necessitated the development of efficient and sustainable adsorption materials. This work explores the synthesis and characterization of Al-doped Cu-Mn (AlxCu0.7Mn0.3Fe2-xO4, where x = 0.1, 0.3, 0.5, 0.7, and 0.9) ferrite as a new adsorbent for the removal of dyes from aqueous solutions. The Al-doped Cu-Mn ferrite was prepared using the solution combustion method and meticulously characterized using various physiochemical techniques, including scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FTIR), X-ray powder diffractometer (XRD), vibrating sample magnetometer (VSM), and Brunauer-Emmer-Teller (BET). Adsorption studies tested the material's ability to remove hazardous dyes such as congo red, methyl orange, methylene blue, and crystal violet from aqueous solutions. The effects of various parameters, including temperature, contact time, and initial dye concentration, were systematically studied. To understand the mechanism of interaction between the adsorbent and the dyes, the adsorption isotherms were examined using the Langmuir, Temkin, D-R, and Freundlich models. The Freundlich isotherms provided the best fit for the experimental data. To clarify the kinetics of the adsorption process, kinetic experiments were conducted using pseudo-first and pseudo-second-order. According to the results of the kinetics analysis, pseudo-second-order kinetics fit the data better, with a higher coefficient of determination values (R2 = 0.981, 0.983, 0.984 & 0.984). Thermodynamic parameters, including enthalpy, Gibbs free energy, and entropy changes, were calculated to determine the nature of the adsorption process, and the result demonstrates that the adsorption process was endothermic and naturally spontaneous. The results indicate that Al-doped Cu-Mn ferrite exhibits high adsorption capacities and favourable thermodynamic properties, making it a promising material for the removal of dyes from industrial wastewater effluents. The study contributes to the field by providing insights into the adsorption mechanisms and potential applications of Al-doped Cu-Mn ferrite in environmental remediation.

Detoxification of lead and arsenic from galamsey polluted water using nano synthesized iron oxide from cupola furnace slag

Drinking of water polluted with heavy metals is a means by which heavy metals bio accumulate in the human body. The rise in galamsey (illegal mining) activities in Ghana has resulted in heavy metal pollution in most water bodies in the country. Above the permissible limits, these metals cause health issues such as cancer, brain damage, kidney damage and other respiratory diseases. Hence, a smart solution to this menace is urgently needed. In this study, iron oxides were recovered from cupola furnace slag by magnetic separation and froth flotation. The recovered iron oxide was modified using electrospinning with the aid of polyvinyl alcohol after which it was calcined and used as adsorbent to detoxify lead and arsenic from two galamsey polluted water bodies in Obuasi, Ghana. Samples of the adsorbent were characterized using X-ray Fluorescence (XRF), X-ray Diffractometry (XRD), Fourier Transform Infrared Spectrometry (FTIR), Scanning Electron Microscopy (SEM) and Brunauer-Emmer-Teller (BET) method. The highest recovery for iron oxide using magnetic separation was 99.42% and that of froth flotation was 90.64%. The recovered iron oxide used as adsorbent was composed 53.04% iron oxide, with major phases like magnetite, hematite, goethite and quartz. Moreover, the surface functional group were determined to be Fe–O and OH. Also, the calcined nano fibres which were spherical in shape with rough surfaces had a specific surface area of 1.1331 m2/g. The contaminated and detoxified water were also analyzed using Atomic absorption Spectroscopy (AAS). Both adsorbent (beneficiated iron oxide and calcined nano fibre) performed well in the adsorption process, with the recovered iron oxide having 97.33% maximum lead removal efficiency while an 81.00% maximum removal efficiency for arsenic. The calcined nano fibre had a maximum of 99.99% removal efficiency for lead and 88.40% maximum efficiency for arsenic. Additionally, the adsorption fits the Langmuirian isotherm model better than the Freundlich model, indicating mono layer coverage.

An Imine-Based Porous 3D Covalent Organic Polymer as a New Sorbent for the Solid-Phase Extraction of Amphenicols from Water Sample.

In this paper, an imine-based porous 3D covalent organic polymer (COP) was synthesized via solvothermal condensation. The structure of the 3D COP was fully characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and powder X-ray diffractometry, thermogravimetric analysis, and Brunauer-Emmer-Teller (BET) nitrogen adsorption. This porous 3D COP was used as a new sorbent for the solid-phase extraction (SPE) of amphenicol drugs, including chloramphenicol (CAP), thiamphenicol (TAP), and florfenicol (FF) in aqueous solution. Factors were investigated for their effects on the SPE efficiency, including the types and volume of eluent, washing speed, pH, and salinity of water. Under the optimized conditions, this method gave a wide linear range (0.1-200 ng/mL) with a high correlation coefficient value (R2 > 0.99), low limits of detection (LODs, 0.01-0.03 ng/mL), and low limits of quantification (LOQs, 0.04-0.10 ng/mL). The recoveries ranged from 83.98% to 110.7% with RSDs ≤ 7.02%. The good enrichment performance for this porous 3D COP might contribute to the hydrophobic and π-π interactions, the size-matching effect, hydrogen bonding, and the good chemical stability of 3D COP. This 3D COP-SPE method provides a promising approach to selectively extract trace amounts of CAP, TAP, and FF in environmental water samples in ng quantities.

Hierarchically porous carbon derived from natural Porphyra for excellent electromagnetic wave absorption

• The porphyra-derived porous carbon (PPC) was fabricated via facile procedures of low temperature pre-carbonization combined with KOH chemical activation. • The porosity of PPC can be readily regulated by adjusting activation temperature. • The hierarchically porous carbon exhibits excellent electromagnetic wave absorption performances. A highly efficient absorber with features including lightweight, broad bandwidth, and tunable electromagnetic property still remains challenging for practical applications. Herein, the Porphyra - derived porous carbon (PPC) was fabricated via facile procedures of low-temperature pre-carbonization combined with KOH chemical activation. The composition, microstructure, and electromagnetic wave absorption properties of the samples were elucidated based on X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer−Emmer−Teller (BET), and vector network analyzer (VNA). The porosity of PPC can be readily regulated by adjusting activation temperature. The PPC obtained at 750 °C was composed of a three-dimensional hierarchically porous carbon network. The C and N elements of natural Porphyra were introduced into the carbon skeleton during the carbonization process. The large specific surface, dopants, and three-dimensional hierarchically porous carbon network can effectively improve the impedance matching and dielectric dissipation, leading to an excellent electromagnetic wave absorption performance. Especially, the optimal reflection loss (RL) value reached –57.75 dB at 9.68 GHz with a broad bandwidth (RL < –10 dB) value of 7.60 GHz at 3.5 mm. Overall, the results indicate that the PPC can provide a new way to achieve lightweight, effective, and sustainable absorbers.

Al2O3/Fe3O4/ZrO2 ternary oxide sorbent: Synthesis, characterization and sorption behavior to fluoride and phosphate ions from aqueous solution

ABSTRACT. Excess quantities of fluoride and phosphate in water bodies can lead to fluorosis and eutrophication problems, respectively. In search of a promising adsorbent targeting these ions, Fe3O4/Al2O3/ZrO2 ternary oxide was synthesized via co-precipitation method and characterized by X-ray diffraction (XRD), Fourier transform-infrared (FTIR) and Brunauer-Emmer-Teller (BET). Its specific surface area was found to be 205 m2/g. The effects of solution pH, adsorbent dose, contact time, agitation speed and initial fluoride and phosphate concentrations were also investigated and the optimum values were 4, 0.5 g, 12 h, 100 rpm and 20 mg/L, respectively, for fluoride and 5, 0.1 g, 8 h, 100 rpm and 10 mg/L, respectively, for phosphate. Fluoride and phosphate adsorptions fitted well with Freundlich and Langmuir isotherm models, respectively and their kinetic data correlated well with the pseudo-second order model. Desorbability study revealed that maximum desorption was achieved at pH 12. Thermodynamics study on the other hand showed that adsorption of fluoride was nonspontaneous and endothermic whereas that of phosphate was spontaneous and exothermic. Application on real water sample decreased the concentration of fluoride from 4.92 to 1.97 mg/L in ground water and phosphate from 1.7 to 0.35 mg/L lake water showing its potential as a promising adsorbent.&#x0D; &#x0D; KEY WORDS: Adsorption, Fluoride, Phosphate, Ternary oxide sorbent, Isotherm models&#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2022, 36(3), 555-569. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v36i3.6 &#x0D;

Adsorption of malachite green and chrysoidine‐Y by Sn‐pillared clay

AbstractThe aim of this research was to pillar the bentonite clay (Bt) with polyhydroxy tin chloride. The synthesized Tin‐pillared interlayer clay (Sn‐PILC) was characterized using X‐ray diffraction (XRD), Fourier Transform Infrared spectra (FT‐IR), Brunauer‐Emmer Teller (BET) analysis, Thermogravimetric analysis (TGA), and Scanning Electron Microscopy (SEM). Adsorption capacity of raw‐Bt and tin pillared interlayer clay (Sn‐PILC) was examined for two dyes, namely, Malachite Green (MG) and Chrysoidine‐Y (CY) from their aqueous solutions. The effects of physicochemical parameters like solution pH, dose, and dye concentration were investigated. The maximum adsorption efficiency at equilibrium dye concentration for Sn‐PILC was 66.229 mg g–1 for MG and 63.792 mg g–1 for CY. Sn‐PILC obeyed Langmuir isotherm for both the dyes whereas raw‐Bt followed Freundlich isotherm. On the other hand, both adsorbents followed PFO as well as PSO kinetic model, indicating physisorption assisted by chemisorption. Thermodynamic studies were performed to determine the adsorption behavior of Sn‐PILC for both the dyes. Regeneration studies revealed 80% efficiency up‐to five adsorption‐desorption cycles.

Porous Organic Polymers Derived from Ferrocene and Tetrahedral Silicon-Centered Monomers for Carbon Dioxide Sorption.

Herein, we present two novel ferrocene-containing porous organic polymers, FPOP-1 and FPOP-2, by the Heck reactions of 1,1′-divinylferrocene with two tetrahedral silicon-centered units, i.e., tetrakis(4-bromophenyl)silane and tetrakis(4′-bromo-[1,1′-biphenyl]-4-yl)silane. The resulting materials possess high thermal stability and moderate porosity with the Brunauer–Emmer–Teller (BET) surface areas of 499 m2 g−1 (FPOP-1) and 354 m2 g−1 (FPOP-2) and total pore volumes of 0.43 cm3 g−1 (FPOP-1) and 0.49 cm3 g−1 (FPOP-2). The porosity is comparable to previously reported ferrocene-containing porous polymers. These materials possess comparable CO2 capacities of 1.16 mmol g−1 (5.10 wt%) at 273 K and 1.0 bar, and 0.54 mmol g−1 (2.38 wt%) at 298 K and 1.0 bar (FPOP-1). The found capacities are comparable to, or higher than many porous polymers having similar or higher surface areas. They have high isosteric heats of up to 32.9 kJ mol−1, proving that the affinity between the polymer network and CO2 is high, which can be explained by the presence of ferrocene units in the porous networks. These results indicate that these materials can be promisingly utilized as candidates for the storage or capture of CO2. More ferrocene-containing porous polymers can be designed and synthesized by combining ferrocene units with various aromatic monomers under this strategy and their applications could be explored.

Adsorption and kinetic studies for removal of basic dyes using pillared bentonites

The aim of this work is to synthesize, characterize, and evaluate the influence of two pillared bentonite (PILC) viz. Iron pillared bentonite (Fe-PILC) and Aluminium Pillared bentonite (Al-PILC) on cationic dye removal. The PILCs were investigated using X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Brunauer-Emmer Teller (BET) analysis, Thermogravimetric analysis (TGA), and Scanning Electron Microscopy (SEM). The parent clay and synthesized PILCs are used as adsorbents for Malachite Green (MG) and Chrysoidine-Y (CY) dyes. In Al-PILC, maximum dye adsorption capacities at equilibrium were 90.080 mg g-1 for MG and 76.369 mg g-1 for CY, Whereas, in Fe-PILC, it were 60.518 mg g-1 and 57.041 mg g-1 for MG and CY, respectively. Parent clay as well as the pillared clays followed Freundlich isotherm model and PSO model.

An Efficient Synthesis of 1,8-Dioxo-Octahydroxanthenes Derivatives Using Heterogeneous Ce-ZSM-11 Zeolite Catalyst

The Ce-ZSM-11 zeolite has been used as an efficient catalyst for the one pot synthesis of 1,8-dioxo-octahydroxanthene derivatives from aromatic aldehyde and 5,5-dimethyl-cyclohexane-1,3-dione under reflux condition. The catalyst was characterized by Powder X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmer-Teller (BET) surface area analysis, and Temperature Programmed Desorption (TPD) techniques. This method provides several advantageous such as use of inexpensive catalyst, simple work-up procedure, high yield of desired product and reusability of catalyst.

Fabrication of Sb2O3/PbO photocatalyst for the UV/PMS assisted degradation of carbamazepine from synthetic wastewater

Photocatalytic degradation of carbamazepine (CBZ) was investigated by hydrothermally synthesized antimony trioxide (Sb2O3)/lead oxide (PbO) photocatalyst. The photocatalyst synthesized with different ratio of Sb2O3 and PbO viz. 1:1, 2:1, 3:1, 1:2, and 1:3. Photocatalyst with 3:1 ratio of Sb2O3 and PbO showed the best photocatalytic activity towards CBZ. Transmission electron microscopy (TEM) analysis suggested that the particle size increased by increasing PbO ratio in the catalyst. It was observed that Sb2O3 synthesis with PbO showed less band gap energy in comparison to Sb2O3. The Brunauer–Emmer–Teller (BET) surface area of the Sb2O3/PbO (3:1) was determined to be 4.78 m2 g−1. In absence of catalyst, very low degradation of CBZ was achieved, while significant enhancement in CBZ degradation was observed in presence of the synthesized catalyst. CBZ degradation followed the pseudo first-order kinetics with rate constant of 0.016 min−1. Increased degradation rate was recorded when peroxymonosulfate (PMS) was used with UV/Sb2O3/PbO. Active species trapping experiment revealed that in CBZ degradation, O2– radical produced by synthesized catalysts played a major role. In presence of PMS, generation of SO4-∙ radical enhanced the catalytic activity of synthesized catalyst.

Constructing benzoxazine-containing porous organic polymers for carbon dioxide and hydrogen sorption

Two novel benzoxazine-containing porous polymers, BPOP-1 and BPOP-2, have been synthesized by the direct Sonogashira-Hagihara coupling reactions of two brominated benzoxazine derivatives with a tetrahedral silicon-centered monomer. These polymers exhibit high porosity with the highest Brunauer-Emmer-Teller (BET) surface area of 623 m2 g−1 and the highest total pore volume of up to 1.78 cm3 g−1. Porosity comparison with other benzoxazine-containing porous polymers shows that the introduction of tetrahedral silicon-centered units into the porous networks is an efficient strategy to improve the porosity of the final porous polymers. For applications, these polymers possess good carbon dioxide uptakes of up to 1.79 mmol g−1 (7.9 wt%) at 273 K and 1.0 bar, a comparably high binding ability with CO2 with an adsorption enthalpy of up to 29.6 kJ mol−1, as well as a moderate hydrogen uptake of up to 5.87 mmol g−1 (1.12 wt%) at 77 K and 1.0 bar. These values are comparable to or higher than other porous polymers with a level of surface areas and previously reported benzoxazine-containing porous polymers, thereby suggesting their potential applications as efficient solid absorbents for storing CO2 and H2.

Ferrocene-linked porous organic polymers for carbon dioxide and hydrogen sorption

Two novel ferrocene-containing porous organic polymers, FPOP-1 and FPOP-2, have been prepared by Sonogashira-Hagihara coupling reactions of 1,1′-diethynylferrocene with tri(4-bromophenyl)phenylsilane or tetrakis(4-bromophenyl)silane. The resultant polymers show high thermal stability and high porosity with Brunauer-Emmer-Teller (BET) surface area of up to 954 m2 g−1 (FPOP-2) and total pore volume of up to 0.74 cm3 g−1 (FPOP-2). The porosity comparison with other ferrocene-containing porous polymers indicates that the introduction of tetrahedral silicon-centered units is beneficial to enhancing the porosity. The gas sorption investigations reveal that these polymers possess comparable CO2 capacities of 1.44 mmol g−1 (6.3%) at 273 K and 1.0 bar, and 0.91 mmol g−1 (4.0 wt%) at 298 K and 1.0 bar (FPOP-2), and comparable H2 uptakes of 7 mmol g−1 (1.4 wt%) (FPOP-2). The values are higher than other non-ferrocene-containing porous polymers with higher porosity, thereby indicating that the incorporation of ferrocene units can improve the gas sorption property. Furthermore, these results demonstrate that these materials can be promisingly utilized as solid absorbents for storing CO2 and H2.

Photoelectrocatalytic degradation of sugarcane factory wastewater using WO3/ZnO thin films

In the present work, layered WO3/ZnO thin films have been prepared by simple chemical spray pyrolysis method. As prepared films are characterized by photoelectrochemical (PEC) solar cell, X-ray diffraction (XRD), Raman spectroscopy, Field emission scanning electron microscopy (FE-SEM), Brunauer–Emmer–Teller (BET) and energy dispersive X-ray spectroscopy techniques. XRD analysis reveals the formation of hexagonal and monoclinic phases of ZnO and WO3 respectively. Raman analysis confirms the formation of layered WO3/ZnO thin films. FE-SEM images demonstrate that the surface morphology of layered WO3/ZnO consists of nano balls like morphology. The specific surface area of the layered WO3/ZnO thin film is found to be 65.12 m2 g−1. The photoelectrocatalytic degradation properties of layered WO3/ZnO thin films were investigated by studying degradation of sugarcane factory wastewater. The end result shows that the degradation percentage of sugarcane factory wastewater using layered WO3/ZnO photo electrode has reached 94.44% after 100 min. under sunlight illumination.

Supercapacitive activities of porous La2O3 symmetric flexible solid-state device by hydrothermal method

In present work, microrod structured La2O3 thin films are grown on to the stainless steel substrate using a binder free single step hydrothermal method. The structural, morphological and active surface area properties of La2O3 thin film are studied by scanning electron microscope (SEM), X-ray diffraction (XRD), contact angle, X-ray photoelectron spectroscopy (XPS), Fourier transformation spectroscopy (FT-IR), and Brunauer-Emmer-Teller (BET) techniques. The La2O3 thin film electrode showed the maximum specific capacitance of 250 F g−1 at a scan rate of 5 mV s−1 with an excellent cycling performance (81%) up to 1000 cycles. The La2O3 thin film electrode shows maximum specific energy and specific power of 80 Wh kg−1 and 1.5 kW kg−1, respectively. The symmetric solid state supercapacitor devices (SSSD) with La2O3 thin film have been fabricated using gel electrolyte (PVA-LiClO4).

Optimization of simultaneous production of waste cooking oil based-biodiesel using iron-manganese doped zirconia-supported molybdenum oxide nanoparticles catalyst

Biodiesel derived from simultaneous esterification and transesterification of waste cooking oil has been attracting consideration as a replacement green fuel for diesel fuels, as it is economically feasible and circumvents the issue of energy versus food, which is estimated to take place with current biodiesel production techniques. In this optimization study, iron-manganese doped zirconia-supported molybdenum oxide catalyst has been prepared and used in the synthesis of waste cooking oil based biodiesel by a simultaneous esterification and transesterification method. The catalyst is prepared via an impregnation method and consequently characterized by XRD, TEM, TGA (thermogravimetric analysis), TPD-NH3, and Brunauer–Emmer–Teller (BET) techniques. The simultaneous process for biodiesel production has been assessed and improved statistically via response surface methodology in combination with the central composite design. It has been established that the process for synthesis of waste cooking oil based biodiesel achieved about 96.8% biodiesel yield at a best condition of 200 °C, waste cooking oil/ methanol molar ratio of 1:30 and 5.0 wt. % as loading of the catalyst. The highest ester yield of 96.8% has been obtained due to the improved physicochemical properties of zirconia-supported molybdenum oxide catalyst which accesses diffusion of the reactants to the active sites.

The microstructure and stability of a Ni-nano-CaO/Al2O3 reforming catalyst under carbonation–calcination cycling conditions

The paper investigated the effect of carbonation–calcination cycling conditions on the microstructure and CO2 sorption property of a sorption complex catalyst. The carbonation operation condition consisted of temperature of 600 °C with 20% CO2–80% N2 and 20% CO2–80% steam atmosphere to simulate the methane reforming reaction conditions; the calcination condition was 800 °C with 100% N2. The Brunauer–Emmer–Teller (BET) surface area and thermogravimetric analysis (TGA) were measured to investigate the microstructure and variation in sorption property of the catalyst after multiple cycles under each condition. Results showed that the microstructure and CO2 sorption capacity of the sorption complex catalyst decayed significantly in the initial carbonation–calcination cycles, especially under a steam atmosphere. X-ray diffraction analysis revealed that a stable compound Ca12Al14O33 formed gradually during the initial carbonation–calcination cycle seven at a temperature of 800 °C. A model is proposed to explain the observed effect of carbonation–calcination cycling on Ca12Al14O33 formation. Furthermore, based on our findings, a new sorption complex catalyst was prepared by pretreating at a high temperature of 900 °C. Evaluation of the catalyst prepared by the ReSER hydrogen production process through 10 circulations revealed significant improvement instability.

Water treatment of hexavalent chromium by gelatin-impregnated-yeast (Gel–Yst) biosorbent

A method is described for biosorption and water treatment of Cr(VI) from aqueous and real water samples by using gelatin-impregnated-yeast as a novel biosorbent. Gelatin and yeast materials (Gel–Yst) were combined together to form a novel eco-friendly, non-toxic, non-carcinogenetic, biodegradable, biocompatible and inexpensive biosorbent to enhance the extraction and biosorption of Cr(VI) from water. The potential affinity characters of Gel–Yst for biosorption of Cr(VI) were studied by the static technique in various buffer solutions. Other controlling experimental factors were also examined and evaluated. The effect of initial concentration of Cr(VI) was also evaluated to follow the postulates of Langmuir, Brunauer–Emmer–Teller (BET) and Dubinin–Radushkevich (D–R) adsorption isotherms. The potential applications of Gel–Yst biosorbent in water treatment processes of Cr(VI) from real acidic and neutral water samples by using multi-stage micro-column techniques were successfully accomplished.

Green nano-catalyst for methanolysis of non-edible Jatropha oil

Non-edible feedstocks are regarded as a sustainable source of renewable energy. In order to find renewable, cheaper and easier methods to obtain energy, attention has been paid to develop potential green catalyst to produce renewable biodiesel. The catalyst was characterized by X-ray diffraction (XRD) results in combination with thermogravimetry–differential thermal analysis (TG–DTA), Brunauer–Emmer–Teller (BET), Fourier transfrom-infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM analysis depicted that calcium methoxide (Ca(OCH3)2) catalysts were in size of 34.7nm. The reaction parameters namely; reaction time, methanol/oil molar ratio, catalyst dosage were investigated for fatty acid methyl ester (FAME) yield. The highest biodiesel yield (95%) was appraised under the optimum condition (i.e. catalyst amount of 2wt.%; methanol/oil molar ratio of 15:1, reaction time of 90min). The Ca(OCH3)2 phase of catalyst can be regarded as an active phase to get high yield of biodiesel which was confirmed from characterization study. Furthermore, important fuel properties were also investigated and satisfied the ASTM D6751 and European 14214 biodiesel standards. Thus, Ca(OCH3)2 catalyst prepared in this study was having efficient, low toxicity, cost effective and easy to prepare for green fuels production especially biodiesel.

Transesterification of Jatropha curcas crude oil to biodiesel on calcium lanthanum mixed oxide catalyst: Effect of stoichiometric composition

Heterogeneous solid mixed oxide (CaO–La2O3) catalysts with different molar ratios of calcium to lanthanum (Ca-to-La) were synthesized by co-precipitation method. The synthesized solid CaO–La2O3 mixed metal oxide catalysts were utilized in transesterification of Jatropha curcus oil as feedstock to produce biodiesel. Under the optimized conditions at 65°C, 4% catalyst dose with 24:1 MeOH to Jatropha oil molar ratio, the transesterification reaction exhibited 86.51% of biodiesel yield. The prepared catalysts were characterized using various techniques such as X-ray diffraction (XRD), nitrogen sorption with Brunauer–Emmer–Teller (BET) method, temperature-programmed desorption of CO2 (CO2-TPD) and scanning electron microscopy (SEM). Influence of Ca-to-La atomic ratio in the mixed metal oxide catalyst, catalyst amount, methanol to oil molar ratio, reaction time, different oils on the fatty acid methyl ester (FAME) yield were appraised. Different catalyst regeneration procedures were also performed to investigate the reusability of the CaO–La2O3 catalyst.

Transesterification of jatropha oil with methanol over Mg–Zn mixed metal oxide catalysts

A design was developed for the transesterification reaction of non-edible Jatropha Curcas oil using a heterogeneous catalysis system to replace the use of a homogeneous catalytic reaction. Investigations were conducted on solid MgO–ZnO mixed metal oxide catalyst bases with different atomic ratios of magnesium to zinc (Mg/Zn). These catalysts were characterized by BET (Brunauer–Emmer–Teller) surface area analysis, X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), and the alkalinity of the catalysts was studied by Temperature Programmed Desorption of carbon dioxide (TPD-CO2). The physicochemical properties of the MgO–ZnO binary system were superior to those of the individual bulk oxides of MgO and ZnO. In addition, the formation of a binary system between MgO and ZnO established an effective method for transesterification processes. In this study, the effects of stoichiometric composition and surface characteristics on the transesterification activity of MgO–ZnO were investigated. The catalysts exhibited high catalytic activity (∼80%) with reliable reusability for biodiesel production.