Incipient Wetness Method Research Articles

Chlorine-containing Ni/AC catalysts for heterogeneous ethanol carbonylation

The heterogeneous ethanol carbonylation of Ni supported on activated carbon (Ni/AC) is typically associated with significant activity loss, largely due to the facile occurrence of carbon deposition and Ni loss. In this study, the chlorine-containing Ni/AC catalysts were synthesized via the incipient wetness method and exhibited superior stability compared to catalysts without chlorine. Correlation of the catalytic performance and catalyst structure revealed that chlorine addition to Ni/AC reduced the amount of carbon deposition. Moreover, it is evident that there is a robust interaction between chlorine and Ni, as evidenced by XPS and H2-TPR, which can significantly impede the Ni loss during the reaction. The results of in-situ DRIFTS and CO-TPD experiments demonstrate that the addition of chlorine impedes the adsorption of iodine species on Ni/AC catalysts, which consequently affects the adsorption capacity of CO closely associated with the product selectivity.

Fe-doped biomass-derived activated carbons as sustainable electrode materials in supercapacitors using different electrolytes

In the search of sustainable and low-cost materials, able to reinforce circular economy, different activated carbons were obtained from agroindustry wastes, by means of a chemical activation route, after the doping of their corresponding biochars with Fe-based species through an incipient wetness method. These activated carbons were assessed as active electrode materials in supercapacitors using various electrolytic media, including aqueous, organic and ionic liquid electrolytes. The electrochemical results obtained revealed an excellent performance for all porous materials and electrolytes under evaluation, reaching the highest specific capacitance of 334F/g at a current density of 0.02 A/g using an aqueous electrolyte. The highest specific capacitance using an organic electrolyte and an ionic liquid electrolyte were 214F/g and 166F/g, respectively. It was found that activated carbons with a relevant mesopores volume, and pore sizes around 1 nm, achieved a better specific capacitance when using aqueous and organic electrolytes. However, heteroatoms as oxygen and iron enhanced the electrochemical performance of the device using the ionic liquid as electrolyte, thus achieving the highest energy and power density values (up to 63 Wh/kg and 1606 W/kg, respectively) among the different systems evaluated.

Tyrosol removal by photo–Fenton–like process using CaAlFe mixed oxides synthesized via hydrocalumite from aluminum salt cake

Solids with potential application in tyrosol (Ty) removal by photo–Fenton processes have been synthesized using aluminum salt cake as a source. Two series of hydrocalumite layered double hydroxides (LDH) were synthesized: one containing structural Fe3+ (occupying octahedral positions in the LDH) and another containing surface impregnated Fe3+; all solids were calcined in air at 750 °C. The solids were characterized by powder X–ray diffraction, FT–infrared spectroscopy, thermal analysis, N2 adsorption–desorption isotherms at –196 °C, particle size distribution and electron microscopy. One of the main differences between the two series was that Fe3+ impregnation by the incipient wetness method and subsequent calcination at 750 °C did not lead to the formation of CaAlFe mixed oxides. The calcined solids were evaluated as photocatalysts in the photo–Fenton process for Ty removal (a typical compound found in olive oil mill wastewater), the samples containing surface Fe3+ showing better results. The solid prepared by impregnation of hydrocalumite with 20% iron and subsequently calcined at 750°C, under the optimum reaction conditions (catalyst dose = 0.5 g/L, [H2O2] = 0.468 g/L and [Ty]0 = 100 mg/L, in the presence of UV light), reached complete Ty removal with contaminant mineralization of 95% after only 60 min reaction. The cyclic study showed that this sample maintained its stability after 3 cycles of reuse without iron leaching, and a better performance than other materials reported in the literature.

Methane dry reforming: influence of the SiO2 and Al2O3 supports on the catalytic properties of Ni catalysts

The effect of the support nature (SiO2, Al2O3, SiO2–Al2O3) on the catalytic performance of Ni-based catalysts prepared by the incipient wetness method was explored in the dry reforming of methane reaction, and the catalysts were characterized by TG-DTA, SEM-EDX, XRD and UV-VIS methods. The results demonstrate that NiO supported on SiO2-modified Al2O3 exhibits superior catalytic performance in methane dry reforming in the temperature range of 650–700 °C.

Interfacial Structures of Heterogeneous Systems Determined by Using in-Situ XAFS

During chemical reactions and catalysis, the surface and interfacial structural properties of materials are considerably important to understand and control the reactions. However, in-situ measurements have many limits during reactions. We used in-situ X-ray absorption fine structure (XAFS) to understand the local structural properties at the surface and the interface of metal catalysts on transition−metal−oxide supports. Pt nanoparticles (NPs) with a mean size of ~1 nm on TiO2 supports are synthesized using an incipient wetness method. In-situ XAFS measurements are performed from the Pt NPs/TiO2 at Pt L3 and Ti K edges during heating from room temperature to 500 ℃ in an H2 environment. Fourier−transformed extended X-ray absorption fine structure (FT−EXAFS), which is a unique tool to quantitatively determine the local structural properties of materials around a selected species element, shows a lack of oxygen atoms as the nearest neighbors of Pt atoms at T = 250 ℃; meanwhile, the wavelet-transformed EXAFS (WT-EXAFS) with enhanced resolution shows a weak but distinguishable oxygen signal around Pt atoms. Pt−O bonds likely exist at the interface of Pt/TiO2, although oxygens on the outer surfaces of Pt NPs are mostly dissociated at T > 250 ℃ in an H2 environment. This finding strongly suggests that the combination of FT−EAXFS and WT−EXAFS can more accurately describe small amounts of light elements bonding with heavy elements than FT−EXAFS can alone. DFT calculations confirm that the presence of extra oxygen atoms at the interfaces of Pt NPs/TiO2, playing a critical role in the stability and the dispersion of Pt NPs.

Interfacial structures of Pt nanoparticles and transition-metal-oxide supports

Local structural properties at the interface of Pt nanoparticles (NPs) and transition−metal−oxide supports are examined using wavelet−transformed extended X−ray absorption fine structure (WT−EXAFS) with an enhanced resolution at Pt L3 edge. The Pt NPs with a mean size of ∼1 nm on TiO2 supports are synthesized using an incipient wetness method. EXAFS measurements are performed from the Pt NPs/TiO2 during heating from room temperature to 250 °C in an H2 environment. Fourier−transformed EXAFS (FT−EXAFS) shows an absence of oxygen atoms around Pt atoms at T = 250 °C; meanwhile, the WT−EXAFS reveals a weak but distinguishable oxygen signal around Pt atoms. Pt–O bonds likely exist at the interface of Pt/TiO2 because oxygens on the outer surfaces of Pt NPs should be dissociated at T = 250 °C under an H2 environment. This finding indicates that the combination of FT−EAXFS and WT−EXAFS can more accurately describe the heterogeneous interfaces of nanostructures.

Role of Dopants in Fine-Tuning the Electrical and Catalytic Properties of Barium Niobate Perovskites Towards High-Temperature Electrolyzer Application

Perovskite materials are being studied for high temperature electrochemical applications such as solid oxide fuel cells (SOFC) and electrolyzers due to their tunable conductivity and catalytic activity. However, high temperature operation poses significant challenges in both fabrication and durable operation that is further complicated by the operating environment.1 We studied barium niobates with various dopants such as Fe, Ni, Ca, Y, and Mg for B site doping while Sr, K, and La are studied for A site doping. These niobates showed enhanced chemical stability in SOFC relevant conditions and catalytic activity towards methane activation. Nb4+/5+ redox couple seem to be a key reason behind this chemical stability while the size and electronegativity of the dopants affect the electrical properties.2 Catalyst exsolution is explored with dopants such as Fe, Ni, and Co under reducing conditions along with surface bound metallic nanoparticles prepared by an incipient wet synthesis method. Chemical stability of these perovskites was analyzed by an in situ TGA measurements under various gas environments followed by analysis of the powders using PXRD, XPS, SEM, and TEM methodologies.3 Methane activation properties are further analyzed in a temperature programmed reaction setup while Electrochemical properties were evaluated in a home-made setup using different electrolyte materials in the temperature range of 700°C to 900°C. Cyclic voltammetry, impedance spectroscopy, and chronoamperometry measurements coupled with continuous mass spectra analysis was utilized to diagnose any correlation between product distribution and applied potential. Our results demonstrate doped barium niobates as a promising candidate for stable operation in high temperature electrochemical applications. The presentation will discuss these results and provide a correlation between dopants and catalytic activity and chemical stability of doped barium niobate perovskites. References (1) Ramaiyan, K. P.; Denoyer, L. H.; Benavidez, A.; Garzon, F. H. Selective Electrochemical Oxidative Coupling of Methane Mediated by Sr2Fe1.5Mo0.5O6-δ and Its Chemical Stability. Commun. Chem. 2021, 4 (1), 139. https://doi.org/10.1038/s42004-021-00568-1.(2) Denoyer, L. H.; Benavidez, A.; Garzon, F. H.; Ramaiyan, K. P. Highly Stable Doped Barium Niobate Based Electrocatalysts for Effective Electrochemical Coupling of Methane to Ethylene. Adv. Mater. Interfaces 2022, 9 (27), 2200796. https://doi.org/10.1002/admi.202200796.(3) Denoyer, L. H.; Benavidez, A.; Garzon, F. H.; Ramaiyan, K. P. Chemical Stability of BaMg0.33Nb0.67-XFexO3-δ in High Temperature Methane Conversion Environments. under communication - ECS Journal of Solid State Science and Technology.

Comparative Study of Commercial Silica and Sol-Gel-Derived Porous Silica from Cornhusk for Low-Temperature Catalytic Methane Combustion.

The synthesis and characterization of sol-gel-derived cornhusk support for low-temperature catalytic methane combustion (LTCMC) were investigated in this study. The prepared cornhusk support was impregnated with palladium and cerium oxide (Pd/CeO2) via the classical incipient wetness method. The resulting catalyst was characterized using various techniques, including X-ray diffraction (XRD), N2 physisorption (BET), transmission electron microscopy (TEM), and hydrogen temperature-programmed reduction (H2-TPR). The catalytic performance of the Pd/CeO2/CHSiO2 catalyst was evaluated for methane combustion in the temperature range of 150-600 °C using a temperature-controlled catalytic flow reactor, and its performance was compared with a commercial catalyst. The results showed that the Pd/CeO2 dispersed on SiO2 from the cornhusk ash support (Pd/CeO2/CHSiO2) catalyst exhibited excellent catalytic activity for methane combustion, with a conversion of 50% at 394 °C compared with 593 °C for the commercial silica catalyst (Pd/CeO2/commercial). Moreover, the Pd/CeO2/CHSiO2 catalyst displayed better catalytic stability after 10 h on stream, with a 7% marginal loss in catalytic activity compared with 11% recorded for the Pd/CeO2/commercial catalyst. The N2 physisorption and H2-TPR results indicated that the cornhusk SiO2 support possessed a higher surface area and strong reducibility than the synthesized commercial catalyst, contributing to the enhanced catalytic activity of the Pd/CeO2/SiO2 catalyst. Overall, the SiO2 generated from cornhusk ash exhibited promising potential as a low-cost and environmentally friendly support for LTCMC catalysts.

Optimization of Aluminium Oxide/Acid‐Treated Palygorskite by Response Surface Methodology and its Application in Adsorptive Separation of the Methanol‐Dimethyl Carbonate Azeotrope

AbstractA low‐cost composite adsorbent aluminium oxide/acid‐treated palygorskite (Al2O3/HPal) was prepared by the total incipient wetness method and succesfully applied for the separation of methanol‐dimethyl carbonate (MeOH‐DMC) azeotrope for the first time. Major synthetic factors influencing the final separation performance were explored by the response surface methodology (RSM) based on Box‐Behnken design (BBD). Adsorbents under optimized synthesis conditions were characterized by XRD, FT‐IR, SEM, TEM and BET analysis. Adsorptive separation performance of Al2O3/HPal were investigated by both static and dynamic experiments. The adsorption capacities for MeOH and DMC were 335.52 mg g−1 and 23.92 mg g−1, respectively, while the selectivity S and the separation factor α towards MeOH equaled to 14.03 and 6.1. Kinetic curves fitted the pseudo‐second‐order model. Isotherm study results indicated two different adsorption behaviors for this azeotrope where heterogeneous multi‐layer adsorption was observed for DMC but monolayer adsorption occurred for MeOH with surface inhomogeneity. Moreover, thermodynamic study suggested that the driving force of the MeOH‐DMC system on Al2O3/HPal included both enthalpy and entropy effects.

Insight into the role of material basicity in the coke formation and performance of Ni/Al2O3 catalyst for the simulated- biogas dry reforming

Biogas, a mixture of methane and carbon dioxide produced from microbial digestion of biomass, waste, or residues, has gained increasing attention from scientists as a valuable resource for producing syngas. This study investigated the effects of different promoters, including calcium, copper, and chromium compounds, on the performance of nickel-based catalysts in biogas reforming. The catalysts were prepared by co-impregnating nickel precursors with the promoters onto the support using the incipient wetness method. The addition of calcium and chromium oxides improved nickel dispersibility, enhanced reducibility, and provided adequate basicity, resulting in superior catalytic activity. Among the promoted catalysts, 0.1Ca–1Ni/Al2O3 demonstrated the best performance with 72% CH4 and 74% CO2 conversions and no significant loss in catalytic activity after 6 h. Additionally, the study found that the basicity of the material was proportional to the transition of amorphous coke into graphitic type, and the advantages and disadvantages of each type of coke were thoroughly discussed.

Novel nickel ceramic filter for hot gas cleanup of tars from syngas

Tars, defined as hydrocarbons having molecular weights above that of benzene, have been considered to be one of the major impurities in syngas preventing largescale commercialization of biomass gasification. Catalytic tar removal has shown the most promise in reforming/eliminating tars compared to physical and thermal techniques. Nickel based catalytic filter was developed using porous ceramic support, which acts both as a particulate filter and tar reformer, resulting in process intensification. The relatively high surface area of the ceramic filter (100 m2/g) makes it an ideal catalyst support. Nickel based ceramic catalysts were prepared using incipient wetness method and evaluated for tar removal effectiveness using naphthalene as a tar simulant. Influence of nickel loading, steam/carbon ratios, and temperatures on steam reforming activity of the catalyst was performed. Promising results were obtained with naphthalene conversions of 76% using a 15 wt% nickel filter over 2 h with very minimal pressure drop across the catalytic filter, offering a promising potential of using catalytic ceramic filters for integrated tar and particulate removal applications.

Investigation of Cu/TiO2 synthesis methods and conditions for CO2 photocatalytic reduction via conversion of bicarbonate/carbonate to formate

This work is aimed at improving the photocatalytic activity of TiO2 in the reduction of CO2. TiO2 and Cu/TiO2 at 5 wt% copper bulk loading were synthesised using the sol-gel method at a pH of 0.4 and 1.5. The synthesised pure TiO2 samples, alongside the commercial TiO2 (Degussa® P25), were also doped with copper via the incipient wetness method. The low pH and the presence of copper inhibited the anatase-rutile transformation. Copper existed in Cu(I) and Cu(II) states in all the doped samples, with the Cu(I) to Cu(II) ratio intimately linked with the anatase to rutile ratio. The UPS data have shown the type II band offset between TiO2 and CuO. The performance of the samples prepared was tested through the reduction of sodium bicarbonate-carbonate buffered at pH > 8. Commercial TiO2 impregnated with Cu demonstrated the highest formate production rate of 173 µmol·g−1·h−1 at pH 11. This study demonstrated the synergetic effect of the anatase-rutile mixture of phases, the reaction pH, and the copper dopant in improving the photocatalytic activity of TiO2.

Oxidation of aldehydes to carboxylic acids over geopolymer supported CuO

This article focuses on the synthesis of copper (II) oxide impregnated mesoporous geopolymer (CuO/Geo) catalyst and its catalytic activity for the oxidation of aldehydes to the corresponding carboxylic acids. CuO/Geo was synthesised by a two-step method. Mesoporous geopolymer was prepared which was used as a support for CuO through incipient wetness method. The synthesized catalyst was characterized using FE-SEM, FT-IR, BET surface area, XRD and XPS. For the oxidation reaction, water was used as the solvent and oxygen as the sole oxidant. On the basis of the experimental observations, CuO/Geo was found to be a good catalyst with 67% conversion of benzaldehyde to benzoic acid, observed in 10 h at 80 °C. It was established from XPS analysis that the oxidation reaction took place via Cu2+/Cu+/Cu2+ transformations. Density functional theory calculations provided insights into the adsorption energetics and the reaction mechanism. The mechanism for benzaldehyde oxidation was developed and the rate determining step was identified. The product formation step was observed to be the rate determining step with the free energy barrier of 59.6 kcal/mol.

Creation of Highly Dispersed Supported Polyoxometalate Cesium Salts via Cation Exchange from Alkylammonium Salts on Supports

AbstractWe have reported several precisely designed metal‐oxo clusters on lacunary polyoxometalate (POM) tetra‐n‐butylammonium (TBA) salts in organic solvents. However, owing to their low thermostability and/or low effective surface area, POM TBA salts are not amenable to heterogeneous catalysts for gas‐phase reactions at high temperature. To avoid this problem, we developed a new preparation method that obtains highly dispersed supported‐POM Cs salts (Cs−POM/support) via cation exchange from the corresponding TBA salts on supports. In this study, a model Keggin‐type POM called TBA4PVMo11O40 (TBA−PVMo11) is supported on oxides (TBA−PVMo11/support) using an incipient wetness method in acetonitrile. This TBA−PVMo11/support was cation‐exchanged with cesium trifluoromethanesulfonate in ethanol to obtain supported‐POM Cs salts (Cs−PVMo11/support). Various characterizations revealed that the TBA−PVMo11/support maintained the original Keggin structure during cation exchange and that Cs−PVMo11 was highly dispersed on the supports. Furthermore, Cs−PVMo11/support maintained the Keggin structure even after calcination at 573 K under an aerobic condition.

Impact of Different Supports on the Performance of Ir Oxide Based Catalysts Synthesized Using Incipient Wetness Method

Development of an active and durable catalyst for oxygen evolution reaction (OER) is a pivotal part of designing an efficient PEM water electrolyser. Iridium is one of the best available catalysts because of its corrosion resistance and activity [1]. Use of Ir is however, limited by its scarcity, limited durability and high cost. Its deposition on a support is a popular way to improve the available surface area, activity and stability [2]. For applications in acidic water electrolysis, supports with the highest chemical resistance and conductivity are preferred. While different methods have been studied to impregnate a support with catalyst nanoparticles, such as Adams’s fusion method and polyol method, their scalability remains questionable due to intensive resource requirements. In this work, Ir oxide based supported catalysts have been synthesized using the incipient wetness method (IWM), one of the most commonly used method of catalyst synthesis in the industry due to its ease of scalability, limited resource requirement and the opportunity to explore the effect of strong metal support interactions. This method however has not been discussed in literature. In this study, Ir oxide (IrOx) (Ir loading on support = 20 wt. percent) was dispersed on commercial supports (ZrO2, Nb2O5, Ta2O5, ATO) using H2IrCl6.xH2O precursor (99.9% trace metal basis, Sigma Aldrich). The catalysts were calcined at 400oC for 2 h in a muffle furnace to produce Ir oxide based catalysts.Electrochemical measurements were carried out on a standard rotating-disk electrode (RDE) system (PINE Research MSR Rotator), and a three-electrode electrochemical cell in 1.0 M sulfuric acid electrolyte (H2SO4 optima grade, Fisher Scientific). The performance of the aforementioned supported Ir oxide catalyst was compared among themselves, and to benchmark commercial catalysts (Umicore Ir Black and IrOx TKK) using metrics such as mass normalized activity (A/g-1 Ir), ECSA normalized activity (mA/cm2 Ir ECSA), Tafel slope (mV/dec) and charge transfer resistance (Rct) measured during the electrochemical test. It was observed that the activity of IrOx/ZrO2 (415 A/gIr, 5.2 mA/cm2 Ir ECSA) was the best among all the 4 impregnated catalysts, and was in fact, more than an order of magnitude greater than that of IrOx/ATO (30 A/gIr, 0.3 mA/cm2 Ir ECSA) at a potential of 1.53 VRHE. A significant drop in the Tafel slope measured in the potential range of 1.45-1.55 VRHE was observed upon changing the support from ATO (80 mV/dec) to ZrO2 (60 mV/dec) hinting towards a change in the reaction mechanism. IrOx/ATO was used as a baseline due to prevalent recognition of ATO as an excellent support for OER catalysts in the literature.Upon comparison with commercial benchmark catalysts it was observed that the Ir ECSA normalized activity of IrOx/Nb2O5, IrOx/Ta2O5, IrOx/ZrO2 surpasses both Umicore Ir black ( 2.23 mA/cm2 Ir ECSA) and IrOx TKK (1.23 mA/cm2 Ir ECSA) with IrOx/ZrO2 providing the highest activity. While Yttria-stabilized zirconia (YSZ) has been a popular choice as an electrolyte and anode for high temperature SOFC due to its non-reducing nature, high thermal stability and mechanical strength, and acceptable oxygen ion conductivity [3], its application in PEM water electrolysis as catalyst support has not been discussed. In this work, we focus on finding the causes for superior performance of ZrO2 as a support for Ir oxide based OER reaction in acidic conditions through the lens of electrocatalysis.

Catalytic pyrolysis of high-density polyethylene over nickel-waste chicken eggshell/HZSM-5

The main objective of the current work is to investigate the effect of nickel–waste chicken eggshell modified Hydrogen exchanged Zeolite Socony Mobil-5 (Ni-WCE/HZSM-5) on pyrolysis of high-density polyethylene (HDPE). Ni-WCE/HZSM-5 was synthesized via the impregnation incipient wetness (IWI) method with Ni and WCE mass loading of 4 and 12 wt% respectively. HZSM-5, CaO, WCE, WCE/HZSM-5, and Ni/HZSM-5 were prepared for comparison purposes with Ni-WCE/HZSM-5. All the synthesized catalysts were characterized for phase analysis, metal loading, surface morphology, and textural properties. The impregnation of nickel and WCE had significantly affected the original framework of HZSM-5, where the crystallinity percentage and average crystal size of HZSM-5 dropped to 44.97% and increased to 47.90 nm respectively. The surface morphology of HZSM-5 has drastically changed from a cubic-like shape into a spider web-like surface after the impregnation of WCE. The BET surface area of HZSM-5 has been lowered due to the impregnation of nickel and WCE, but the total pore volume has increased greatly from 0.2291 cm3/g to 0.2621 cm3/g. The catalyst performance was investigated in the pyrolysis of HDPE via a fixed bed reactor and the pyrolysis oil was further analysed to evaluate the distribution of C6 to C9> hydrocarbons. Among the tested catalytic samples, the highest pyrolysis oil yield was achieved by WCE (80%) followed by CaO (78%), WCE/HZSM-5 (63%), HZSM-5 (61%), Ni/HZSM-5 (44%) and Ni-WCE/HZSM-5 (50%). For hydrocarbon distribution in pyrolysis oil, the Ni/HZSM-5 produced the highest of total C6 and C7 hydrocarbons at 12% and 27% respectively followed by WCE/HZSM-5 (4% and 20%), non-catalytic (5% and 13%), Ni-WCE/HZSM-5 (0% and 15%), WCE (0% and 10%), HZSM-5 (0% and 6%) and CaO (0% and 0%).

Employing an Artificial Neural Network in Correlating a Hydrogen-Selective Catalytic Reduction Performance with Crystallite Sizes of a Biomass-Derived Bimetallic Catalyst

A predictive model correlating the properties of a catalyst with its performance would be beneficial for the development, from biomass waste, of new, carbon-supported and Earth-abundant metal oxide catalysts. In this work, the effects of copper and iron oxide crystallite size on the performance of the catalysts in reducing nitrogen oxides, in terms of nitrogen oxide conversion and nitrogen selectivity, are investigated. The catalysts are prepared via the incipient wetness method over activated carbon, derived from palm kernel shells. The surface morphology and particle size distribution are examined via field emission scanning electron microscopy, while crystallite size is determined using the wide-angle X-ray scattering and small-angle X-ray scattering methods. It is revealed that the copper-to-iron ratio affects the crystal phases and size distribution over the carbon support. Catalytic performance is then tested using a packed-bed reactor to investigate the nitrogen oxide conversion and nitrogen selectivity. Departing from chemical characterization, two predictive equations are developed via an artificial neural network technique—one for the prediction of NOx conversion and another for N2 selectivity. The model is highly applicable for 250–300 °C operating temperatures, while more data are required for a lower temperature range.

Optimization of mirtazapine loaded into mesoporous silica nanostructures via Box-Behnken design: in-vitro characterization and in-vivo assessment

Employment of mesoporous silica nanostructures (MSNs) in the drug delivery field has shown a significant potential for improving the oral delivery of active pharmaceutical products with low solubility in water. Mirtazapine (MRT) is a tetracyclic antidepressant with poor water solubility (BCS Class II), which was recently approved as a potent drug used to treat severe depression. The principle of this research is to optimize the incorporation of Mirtazapine into MSNs to improve its aqueous solubility, loading efficiency, release performance, and subsequent bioavailability. The formulation was optimized by using of Box-Behnken Design, which allows simultaneous estimation of the impact of different types of silica (SBA-15, MCM-41, and Aluminate-MCM-41), a different drug to silica ratios (33.33%, 49.99%, and 66.66%), and different drug loading procedures (Incipient wetness, solvent evaporation, and solvent impregnation) on the MRT loading efficiency, aqueous solubility and dissolution rate. The optimized formula was achieved by loading MRT into SBA-15 at 33.33% drug ratio prepared by the incipient wetness method, which displayed a loading efficiency of 104.05%, water solubility of 0.2 mg/ml, and 100% dissolution rate after 30 min. The pharmacokinetic profile of the optimized formula was obtained by conducting the in-vivo study in rabbits which showed a marked improvement (2.14-fold) in oral bioavailability greater than plain MRT. The physicochemical parameters and morphology of the optimized formula were characterized by; gas adsorption manometry, scanning electron microscopy (SEM), polarized light microscopy (PLM), Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and X-ray powder diffraction (XRPD).

Unveiling the role of high-valent copper cations in the selective catalytic reduction of NOx with NH3 at low temperature

Cu3+ cation is present in some particular materials, however, to the best of our knowledge, it remains unclear what role of Cu3+ plays during selective catalytic reduction of NOx by NH3 (NH3-SCR) to date yet. Herein, LaCuO3-x supported on mesoporous Al2O3 was designed and constructed via an incipient wetness method, and the effect of Cu3+ on the adsorption and activation of NOx and NH3 species in the NH3-SCR of NOx was systematically probed by experiment and in-situ DRIFTS for the first time. It unravels that LaCuO3-x/meso-Al2O3 with abundant Cu3+ species exhibits a remarkably higher catalytic activity for NH3-SCR of NOx at low temperature range (100 ∼ 280 °C) than CuO/meso-Al2O3 counterpart because of the unique nature of Cu3+ species, which endows the more acid sites and higher redox property, thereby promoting the adsorption and activation of ammonia and NOx, and thereafter accelerating the intrinsic reaction rate of LaCuO3-x/meso-Al2O3. It should be the root reason resulting in the perceptibly higher catalytic activity of LaCuO3-x/meso-Al2O3 compared with that of CuO/meso-Al2O3 at low temperature. Therefore, the finding here offers great promise for the preparation of highly-efficient NH3-SCR catalyst with excellent catalytic activity at low temperatures in future.

Production of biodiesel from salvia mirzayanii oil via electrolysis using KOH/Clinoptilolite as catalyst.

In recent years, fossil fuels are the main energy supply in both transportation and industry. Their increasing consumption has been causing global warming and acid raining. One of the alternative fuels that is considered today is biodiesel, which is clean and eco-friendly. The main method for biodiesel production is transesterification reaction of triglyceride oil with methanol in the presence of a suitable catalyst. In this research, biodiesel was produced from Salvia mirzayanii oil in the presence of KOH/Clinoptilolite catalyst. The impregnation, hydrothermal, and incipient wetness methods were used for loading KOH on the Clinoptilolite support to produce biodiesel via electrolysis method. The characteristics of the KOH/Clinoptilolite catalyst were examined through scanning electron microscopy (SEM), energy dispersive X-ray Spectroscopy (EDX), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analyses. The effects of key parameters including catalyst amount, methanol to oil molar ration, reaction time, reaction temperature, co-solvent type and its proportion, electrolysis voltage, catalyst reusability, and KOH concentration were examined on the biodiesel yield. The results of elemental analysis confirmed that KOH was well loaded on Clinoptilolite support. The highest yield of biodiesel was obtained 79% in the presence of 10wt% catalyst, alcohol to oil ratio of 9:1, acetone concentration of 10wt%, temperature of 60°C, and voltage of 10V. The results of GC-MS, FTIR and H-NMR analyses illustrated that biodiesel as a product was produced with good quality. Based on the obtained results, in all three methods of catalyst synthesis KOH was loaded on Clinoptilolite support but at the end of the transesterification reaction only the catalyst synthesis via incipient wetness method could be reused three times under optimum reaction conditions. The produced biodiesel had high quality, whose physical and chemical properties had good agreement with ASTM, EN 14214, IS 15607 standards. Since the salvia mirzayanii oil is an appropriate feedstock source for biodiesel production, it is suggested to use salvia mirzayanii oil and KOH/Clinoptilolite catalyst to produce biodiesel on industrial scale.