Wet Impregnation Method Research Articles

Direct Production of Sustainable Aviation Fuel by Deoxygenation and Isomerization of Triglycerides Over Bifunctional Ir-ReOx/SAPO-11 Catalyst.

Catalytic thermochemical conversion offers a sustainable method to upgrade oil-based feedstocks into highly valuable biofuel, aligning with the modern biorefinery concept. Herein, a series of IrRe/SAPO-11 catalysts with different Ir to Re molar ratios compared to reference Ir/SAPO-11 and Re/SAPO-11 catalysts was prepared using a wetness impregnation method. These catalysts were used for the direct production of sustainable aviation fuels (SAFs) via efficient hydrodeoxygenation and hydroisomerization of triglycerides. The catalyst screening confirmed that the optimum IrRe/SAPO-11 catalyst, with an equivalent Ir to Re molar ratio, exhibited the highest hydrodeoxygenation activity under milder operation conditions than the conditions used in previous studies. Increasing the reaction temperature up to 330 °C enhanced the formation of iso-alkanes in the liquid product, achieving a freezing point of -31.4 °C without additional cold flow improvers. Furthermore, a long-term stability experiment demonstrated that the developed Ir-Re system exhibited exceptional performance over 150 h. This excellent catalytic activity and stability of the bifunctional IrRe/SAPO-11 catalyst was owing to its suitable interface between metallic and oxide sites, mixed mesoporous structures, reduced catalyst size, and increased Lewis acid ratio, as confirmed by our comprehensive characterizations.

The Role of The Ni/HZSM-5 Ratio on The Anisole Hydrodeoxygenation Reaction

ABSTRACT. Bio-oil is a renewable energy source with high oxygen levels, and anisole is a chemical widely employed in research to represent it. Catalytic hydrodeoxygenation (HDO) reduces the oxygen content. A catalyst known as nickel-modified HZSM-5 has shown promising results for HDO. Meanwhile, catalyst efficiency depends on the Ni/HZSM-5 ratio. So, this study aims to determine how the Ni/HZSM-5 ratio influences the catalyst's properties, activity, and selectivity in anisole HDO. The Ni/HZSM-5 catalyst was made using the wet impregnation method with various ratios of Ni/HZSM-5. The catalysts were analyzed for their morphology using scanning electron microscopy-energy-dispersive X-ray (SEM-EDX). The diffraction patterns were studied using X-ray diffraction (XRD). Surface area and porosity were determined through gas sorption analysis (GSA). Then, the acidity strength was evaluated via temperature-programmed ammonia desorption (NH3-TPD). The characterization results show Ni was successfully impregnated and distributed evenly in HZSM-5 without changing the primary structure. Adding Ni metal to HZSM-5 increases the surface area of the catalyst but reduces its acid strength. The catalytic performance of the catalysts was then evaluated in a flow reactor at 400 °C, using 15 mL/min H2 gas. The liquid products of the reaction were analyzed using gas chromatography-mass spectroscopy (GC-MS). The results of the catalytic performance show that Ni4.5/HZSM-5 has the highest catalytic activity in anisole conversion. At the same time, Ni6.4/HZSM-5 shows the highest selectivity towards benzene-toluene-xylene (BTX). Keywords: Hydrodeoxygenation, nickel, anisole, heterogeneous catalyst, acidity.

High efficient CuCeO2‐δ/SiO2 catalyst for RWGS reaction: impact of Ce content and loading sequence

AbstractThe extensive use of fossil energy leads to wanton emission of CO2 and serious environmental problems. The exploration of high‐performance catalysts plays a pivotal role in CO2 resource utilization. In this paper, CuCeyK catalysts are prepared by wet impregnation method using ordered mesoporous SiO2 as support for the reverse water gas shift (RWGS) reaction. The physicochemical properties of the prepared catalysts are characterized by H2‐TPR, BET, XRD, Quasi in‐situ XPS, H2‐TPD, and CO2‐TPD techniques. The results demonstrate thatthe Cu0 species can form synergistic effects with oxygen vacancies (Ov) to enhance the CuCeyK catalytic performance. Additionally, the electronic effects between Ce and Cu not only enhances the adsorption and activation performances of the catalyst towards CO2 and H2 molecules, but also effectively suppresses the sintering of Cu0 species, thereby enhancing the stability of the corresponding catalyst. It is worth mentioning that the Ce content also directly affects the catalytic performances of the CuCeyK catalyst. The CuCe15K catalyst with a Ce content of 15% displays excellent CO2 hydrogenation performances, and the CO2 conversion and CO selectivity up to 41 % and 100 % at 420 °C, respectively. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Fabrication of SrTiO3 anchored rGO/g-C3N4 photocatalyst for the removal of mixed dye from wastewater: dual photocatalytic mechanism

A metal-free combination of rGO/g-C3N4-coupled SrTiO3 (SRN) ternary nanocomposite prepared via a wet impregnation method for UV–Vis light photocatalytic applications. Various physicochemical properties of the samples were investigated by several spectroscopic techniques including X-ray diffraction (XRD), FT-IR, Raman, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FE-SEM-EDX), high-resolution transmission electron microscopy (HR-TEM), UV–Vis, photoluminescence (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) surface area analysis. The data suggest agglomerated SRT nanoparticles are dispersed and distributed throughout the surface of the rGO sheets and GCN nanostructures. The photocatalytic performance of the SRN towards combined mixed dye and its degradation activities were evaluated towards the most common industrial effluents, Rhodamine B (RhB) and Methylene blue (MB), under UV–Vis light illumination. The results revealed that the degradation efficiency of the SRN photocatalyst shows excellent performance compared with that of the binary composition and the pure SrTiO3 (SRT) sample. The reaction rate constant for RhB was estimated to be 0.0039 min−1 and for MB to be 0.0316 min−1, which are 3.26 (RhB) and 4.21 (MB) times faster than the pure SRT sample. The enhanced degradation efficiency was attained not only by interfacial formation but also by the speedy transportation of electrons across the heterojunction. After 5 runs of the photocatalytic recylic process, the SRN photocatalyst exhibited ultimate stability without structural changes, and no noticeable degradation was observed. The outcomes of the ternary SRN nanocomposite manifest a dual photocatalytic scheme, the photocatalytic enrichment could be caused by the Z-scheme charge transfer process between GCN, SRT, and rGO nanocomposite, which helps effectual charge separation and keeps a high redox potential. From the results, SRN sample provides insight into the integration of an effective and potential photocatalyst for wastewater treatment toward real-time environmental remediation applications.

Optimizing Light Dynamics: Designing a Ni-MOF Functionalized g-C3N4 Type II Heterostructure and a Ti3C2 MXene Schottky Junction for the Efficient Photocatalytic H2 Production.

The photocatalytic production of hydrogen (H2) from water is a vital avenue towards sustainable energy and addressing global environmental challenges. To maximize efficiency, harnessing the synergistic effects of multiple co-catalysts is essential, as these interactions can significantly enhance performance. In this study, we introduce a ternary heterojunction composed of a nickel-imidazole framework (Ni-MOF), graphitic carbon nitride (CN), and Ti3C2 MXene (TC), employing solvothermal and wet impregnation methods, featuring a well-designed Type II heterojunction and a noble metal-free Schottky junction for efficient hydrogen evolution. The Type II heterojunction between Ni-MOF and CN minimizes charge carrier recombination and promotes photogenerated electron generation, while TC as an electron acceptor enhances electron capture, increases participation in surface reactions, and augments active sites. Consequently, the Ni-MOF/CN/TC hybrid catalyst achieves outstanding photocatalytic hydrogen evolution under visible light, with a peak production rate of 1044.46 μmol/g over 3 hours, surpassing CN by 13 fold and Ni-MOF/CN by 50 %. This work provides insights into MXene-based ternary systems, emphasizing the potential for enhanced light absorption and efficient charge separation, making it a promising platform for photocatalytic applications.

RuNi/TiZr-MMO Catalysts Derived from Zr-Modified NiTi-LDH for CO-Selective Methanation.

CO-selective methanation (CO-SMET) is an efficient hydrogen-rich (H2-rich) gas purification technology for proton exchange membrane fuel cells. It is vital to develop suitable catalysts with good low-temperature activity for CO-SMET reactions. In this study, RuNi/TiZrx-mixed metal oxide (RuNi/TiZrx-MMO) catalysts with different molar ratios of Zr/Ti, derived from a Zr-promoted NiTi-layered double hydroxide (NiTi-LDH) precursor were successfully prepared using the co-precipitation and wet impregnation methods. The RuNi/TiZr0.2-MMO catalyst possesses higher catalytic performance in a lower temperature window of 180-280 °C, which can reduce the CO concentration to be below 10 ppm. The characterization results obtained from XRD, BET, SEM, TEM, XPS, TPR, and TPD suggest that the addition of ZrO2 increases the surface area of the catalyst, improves the dispersion of metallic nanoparticles, increases the reducibility of Ni species on the RuNi/TiZr0.2-MMO catalyst's surface, and enhances the adsorption and activation ability of CO, resulting in remarkable catalytic performance at lower reaction temperatures. Moreover, the RuNi/TiZr0.2-MMO catalyst demonstrated long-term catalytic stability and carbon resistance.

Utilizing an Integrated Flow Cathode-Membrane Filtration System for Effective and Continuous Electrochemical Hydrodechlorination.

Pd-based electrodes are recognized to facilitate effective electrochemical hydrodechlorination (EHDC) as a result of their superior capacity for atomic hydrogen (H*) generation. However, challenges such as electrode stability, feasibility of treating complex matrices, and high cost associated with electrode synthesis hinder the application of Pd-based electrodes for EHDC. In this work, we investigated the feasibility of degrading 2,4-dichlorophenol (2,4-DCP) by EHDC employing Pd-loaded activated carbon particles, prepared via a simple wet-impregnation method, as a flow cathode (FC) suspension. Compared to other Pd-based EHDC studies, a much lower Pd loading (0.02-0.08 mg cm-2) was used. Because of the excellent mass transfer in the FC system, almost 100% 2,4-DCP was hydrodechlorinated to phenol within 1 h. The FC system also showed excellent performance in treating complex water matrices (including hardness ion-containing wastewater and various other chlorinated organics such as 2,4-dichlorobenzoic acid and trichloroacetic acid) with a relatively low energy consumption (0.26-1.56 kW h m-3 mg-1 of 2,4-DCP compared to 0.32-7.61 kW h m-3 mg-1 of 2,4-DCP reported by other studies). The FC synthesized here was stable over 36 h of continuous operation, indicating its potential suitability for real-world applications. Employing experimental investigations and mathematical modeling, we further show that hydrodechlorination of 2,4-DCP occurs via interaction with H*, with no role of direct electron transfer and/or HO•-mediated processes in the removal of 2,4-DCP.

Cu nanowire – impregnated activated carbon fiber for antibacterial applications

Metal nanowires are a 1D structure possessing distinct properties suitable for diverse applications. Copper nanowires (Cu NW) have garnered attention in recent times, particularly as an antibacterial material. Nevertheless, their utilization as a bandage or dressing material necessitates a suitable support, an aspect that remains largely unexplored. In this study, we have developed activated carbon fiber (ACF)-supported Cu NW using the chemical reduction and wet impregnation methods. Tested against Escherichia coli and Staphylococcus aureus, Cu NW/ACF exhibits 83 - 86% reduction in the bacterial growth. The improved antibacterial activity of the material is attributed to the relatively slow release of Cu ions from Cu NW, attributed to the Kelvin effect. Biocompatibility test confirms less than 1.5% hemolysis of erythrocytes, indicating the potential application of the composite as a bandage or dressing material.

Enhanced coke resistant Ni/SiO2@SiO2 core–shell nanostructured catalysts for dry reforming of methane: Effect of metal-support interaction and SiO2 shell

Suppressing coke formation on nickel-based catalysts used in methane-dry reforming is one of the most important issues. We investigate the effect of nickel metal-support interaction and outer porous silica shells on the coke formation in methane dry reforming over Ni/SiO2@SiO2 core–shell catalysts. Using a simple ammonia evaporation method, the Ni/SiO2_AE catalyst, which has highly dispersed nickel nanoparticles with ca. 7 nm, was synthesized and coated with an outer porous silica shell to produce a Ni/SiO2_AE/SiO2 core shell catalyst. Based on the TEM and N2 isotherm results, a 20 nm thick SiO2 shell having pores with a size of about 2 nm was uniformly coated on the Ni/SiO2_AE catalyst. H2-TPR, and XPS analysis results suggest that the Ni/SiO2_AE and Ni/SiO2_AE@SiO2 catalysts have high nickel dispersion. This high dispersion is due to strong metal-support interactions and the formation of Ni phyllosilicate species. On the other hand, the ones synthesized by wet impregnation method have low nickel dispersion due to weaker metal-support interactions. The Ni/SiO2_AE@SiO2 core–shell catalyst showed stable catalytic activity under methane dry reforming conditions at 600 °C. On the other hand, the Ni/SiO2_WI and Ni/SiO2_AE catalysts showed rapid deactivation due to severe coke formation. It can be concluded that the strong metal-support interaction and the silica shell can suppress catalyst deactivation caused by coke formation very effectively.

Ni-Doped Activated Carbon from Invasive Plants as a Potential Catalyst

In this study we synthesized and characterized Ni/AC (Activated Carbon) systems. AC was obtained through pyrolysis of golden rod’s dried biomass. Ni nanoparticles were deposited on AC’s surface using a wet impregnation method from a nickel nitrate solution. SEM, MP-AES and DSC-TGA techniques were used for surficial and structural characterization, while ash content was made to check mineral ingredients input. The DSC-TGA study revealed that all carbons show good thermal stability up to 900 °C, which is far above operating temperatures in the methanation process. For all three carbons the BET isotherms were made as well. They show that in most cases the carbon’s surface is well developed and can adsorb decent amounts of metal. MP-AES helped to evaluate the efficiency of the impregnation process, which reached 76 mg of Ni per 1 g of carbon. The SEM-EDS study showed good distribution of Ni nanoparticles across AC’s surface. We also made a comparison of our systems to similar materials from other works.

Dry reforming of methane at high temperature and elevated pressure over nickel spinellized powder catalyst and pellets prepared from a metallurgical residue

AbstractThe coke deposition on catalysts is a significant problem in the dry reforming of methane at elevated pressures. Understanding and controlling the mechanisms of such deposition is essential in developing a techno‐economically viable industrial application for the production of synthesis gas and/or hydrogen. The patent‐pending nickel‐supported upgraded slag oxide (Ni‐UGSO) catalysts, in powder form, have demonstrated excellent performance and achieved equilibrium in dry reforming, steam reforming and mixed methane reforming in a gram‐scale laboratory packed bed reactor under barometric pressure. In this extended study, Ni‐UGSO pellets were prepared using the wet impregnation method. The pelletized form of said catalyst was studied under elevated pressure to imitate the industrial operating conditions in a kilogram‐scale laboratory packed bed reactor. The characterization of the fresh and used catalytic formulation produced data allowing the investigation of the physicochemical properties of catalysts and the effects of metal dispersion, reaction pressure and crystallite size, as well as the role of side reactions on the nature of the coke. The metal support nature favored the interaction between the Ni metal and spinels (UGSO), and the presence of the clay binder (kaolinite, quartz) improved the pellet morphology, provided higher Ni dispersion, maintained the crystallite size, reduced the coke formation and achieved similar or higher performance with respect to Ni‐UGSO powder despite having 85% less surface area. The Ni‐UGSO pellet showed negligible coke deposits from 1 to 6.5 atm and operated successfully for 24 h at 5.5 atm, 800°C and gas hourly space velocity 810 L/(h kg cat). This study provides new insight into the design of a more efficient and robust catalyst for methane dry reforming at elevated pressures, which is critical for potential future transfer at the industrial level.

MgO Modified by X2, HX, or Alkyl Halide (X = Cl, Br, or I) Catalytic Systems and Their Activity in Chemoselective Transfer Hydrogenation of Acrolein into Allyl Alcohol.

A new type of catalyst containing magnesium oxide modified with various modifiers ranging from bromine and iodine, to interhalogen compounds, hydrohalogenic acids, and alkyl halides have been prepared using chemical vapor deposition (CVD) and wet impregnation methods. The obtained systems were characterized using a number of methods: determination of the concentration of X- ions, surface area determination, powder X-ray diffraction (PXRD), surface acid-base strength measurements, TPD of probe molecules (acetonitrile, pivalonitrile, triethylamine, and n-butylamine), TPD-MS of reaction products of methyl iodide with MgO, and Fourier transform infrared spectroscopy (FTIR). The catalysts' activity and chemoselectivity during transfer hydrogenation from ethanol to acrolein to allyl alcohol was measured. A significant increase in the activity of modified MgO (up to 80% conversion) in the transfer hydrogenation of acrolein was found, while maintaining high chemoselectivity (>90%) to allyl alcohol. As a general conclusion, it was shown that the modification of MgO results in the suppression of strong basic sites of the oxide, with a simultaneous appearance of Brønsted acidic sites on its surface. Independently, extensive research on the reaction progress of thirty alkyl halides with MgO was also performed in order to determine its ability to neutralize chlorinated wastes.

Synthesis of ultrafine Mo2N particles supported on N doped carbon material for guaiacol hydrodeoxygenation

A series of Mo2N particles supported on nitrogen-doped carbon (Mo2N@NC) catalysts for guaiacol hydrodeoxygenation were synthesized in situ through a one-step method employing dopamine as C and N resources and ammonium molybdate as Mo resource, respectively. During synthesis, molybdate ions are adsorbed on dopamine because of a complexation between them; then dopamine/molybdate ions/TMB/F127 nanoemulsions are formed. After polymerization, growth, drying, and carbonization, Mo2N particles supported on nitrogen-doped carbon catalysts are obtained. Because of the interaction between Mo and N, Mo2N particles are anchored onto the support, preventing the aggregation of Mo2N during carbonization. As a result, ultrafine Mo2N particles with a size of 1.0–1.3 nm are highly dispersed on Mo2N@NC catalysts. The guaiacol hydrodeoxygenation for these Mo2N@NC catalysts was performed at 280–380 °C, a H2 flow rate of 80 mL/min and different pressures and weight hourly space velocities. Among them, Mo2N@NC with a Mo2N loading of 40 % presents the highest guaiacol conversion (99.9 %) and aromatic hydrocarbon selectivity (80.2 %), which is also better than Mo2N/C with a Mo2N loading of 40 % prepared by the wet impregnation method.

An experimental study of the endothermic catalytic cracking of hydrocarbon aviation fuels under extreme conditions

Methylcyclohexane (MCH) is a suitable surrogate endothermic fuel that can operate under extreme conditions and it can be utilized to better understand the mechanisms of endothermic catalytic cracking and coke generation in jet engines. Zn-impregnated desilicated Zeolite Socony Mobil–5 (ZSM-5) zeolite catalysts have been successfully prepared and studied for aviation fuel cracking under high temperature and pressure conditions (550 °C; 50 bar). First, micropore ZSM-5 was desilicated by the alkali treatment method with NaOH to increase the mesopore distributions. In the second step, Zn-doped mesopore ZSM-5 zeolites were prepared by the incipient wetness impregnation method with an aqueous solution of zinc nitrate. After the endothermic pyrolysis of MCH fuel over the modified zeolite catalysts, the condensed liquid product fraction (%) was analyzed. It can be deduced that a reasonable combination of these advanced synthesis strategies can increase catalytic cracking performance. This study showed that, in the context of endothermic catalytic cracking of hydrocarbon aviation fuels at supercritical jet conditions, Zn-doped desilicated zeolites exhibited a decreased quantity of coke deposition.

Solidification of deep eutectic solvent containing fimasartan through wet impregnation and exploration of flow attributes by modified SeDeM-SLA expert system

The solidification of deep eutectic solvent (DES) through wet impregnation techniques on inert solid carriers is an interesting approach that offers better processing attributes and excellent stability. Herein, DES of Fimasartan (FS) was developed to improve its solubility and bioavailability. The selected DES-FS was solidified by wet impregnation method employing Nesulin US2 and Aerosil 200. The SeDeM-SLA (solid–liquid adsorption) system was employed to investigate flow attributes of solidified DES-FS. Further, the selected solidified DES-FS (A) was characterized by Fourier transforms infrared spectroscopy (FTIR), Powder X-ray diffraction (PXRD), Differential scanning calorimetry (DSC), Scanning electron microscopy (SEM). The DES comprising Choline Chloride (ChCl): Glycerol (Gly) (1:3) revealed maximum drug solubility (35.6 ± 2.2 mg/mL) and thus opted for solidification. Solidification through wet impregnation was employed using 1:0.5 ratios (DES-FS to carriers). The Index of Good Flow (IGF) value was calculated from the SeDeM-SLA expert system, which indicates the better flow characteristics of solidified DES-FS, particularly with Neusilin US2 [SDES-FS (A)]. The solid-state evaluation data of SDS-FS (A) suggested a transition of FS to an amorphous form, resulting in an increment in solubility and dissolution. A similar trend was reported in the in vivo pharmacokinetic study, which indicated a 2.9 folds increment in the oral bioavailability of FS. Furthermore, excellent stability, i.e., a shelf life of 28.44 months, reported by SDES-FS (A) in accelerated stability studies, suggests better formulation perspectives. In a nutshell, the present study evokes the potentiality of performing solidification through wet impregnation and successful implementation of the SeDeM-SLA expert model, which could find wide applications in pharmaceutical science.

Tailoring CuOx loading on CoFe2O4 nanocubes photocatalyst for superior photocatalytic degradation of triclosan pollutants under VL irradiation and toxicological evaluation

In this study, we report the development of a novel CuOx(3 wt%)/CoFe2O4 nanocubes (NCs) photocatalyst through simple co-precipitation and wet impregnation methods for the efficient photocatalytic degradation of triclosan (TCS) pollutants. Initially, rod-shaped bare CoFe2O4 was synthesized using a simple co-precipitation technique. Subsequently, CuOx was loaded in various percentages (1, 2, and 3 wt%) onto the surface of bare CoFe2O4 nanorods (NRs) via the wet impregnation method. The synthesized materials were systematically characterized to evaluate their composition, structural and electrical characteristics. The CuOx(3 wt%)/CoFe2O4 NCs photocatalyst exhibited superior photocatalytic degradation efficiency of TCS (89.9%) compared to bare CoFe2O4 NRs (62.1 %), CuOx(1 wt%)/CoFe2O4 (80.1 %), CuOx(2 wt%)/CoFe2O4 (87.0 %) under visible light (VL) irradiation (λ ≥ 420 nm), respectively. This enhanced performance was attributed to the improved separation effectiveness of photogenerated electron (e−) and hole (h+) in CuOx(3 wt%)/CoFe2O4 NCs. Furthermore, the optimized CuOx(3 wt%)/CoFe2O4 NCs exhibited strong stability and reusability in TCS degradation, as demonstrated by three successive cycles. Genetic screening on Caenorhabditis elegans showed that CuOx(3 wt%)/CoFe2O4 NCs reduced ROS-induced oxidative stress during TCS photocatalytic degradation. ROS levels decreased at 30, 60, and 120-min intervals during TCS degradation, accompanied by improved egg hatching rates. Additionally, expression levels of stress-responsible antioxidant proteins like SOD-3GFP and HSP-16.2GFP were significantly normalized. This study demonstrates the efficiency of CuOx(3 wt%)/CoFe2O4 NCs in degrading TCS pollutants, offers insights into toxicity dynamics, and recommends its use for future environmental remediation.

Insight into interface chemistry of metal oxides anchored on biowaste-derived support for highly selective glycolysis of waste polyethylene terephthalate

The unprecedented rise of polyethylene terephthalate (PET) waste demands sustainable solutions like catalytic glycolysis, a promising recycling technology that mitigates environmental harm. Herein, we synthesized a series of novel Mo-Zn@SiO2 catalysts for PET glycolysis, derived from readily available rice husk ash via the wetness impregnation method. The optimum Mo-Zn@SiO2 exhibits exceptional activity, achieving complete PET conversion and a 90.4 % yield of bis(2-hydroxyethyl) terephthalate (BHET) – one of the highest performances reported for heterogeneous catalysts. Density functional theory (DFT) calculations suggest that the formation of the ZnMoO4 phase optimizes reactant and product adsorption energies, enhancing Lewis acidity and facilitating depolymerization. Kinetic studies reveal a low apparent activation energy (139.27 kJ/mol) for BHET production at 175–190 °C. Additionally, the catalyst demonstrates excellent recyclability, maintaining activity after five cycles. This work presents a viable and efficient strategy for PET waste valorization using a low-cost, readily available, and easily synthesized catalyst.

Effect of the amount and type of active metal and its impregnation sequence on bio-fuel production

This study aims to investigate biofuel production from biomass-derived bio-oil and examine the impact of selecting different active metals, their quantities, and synthesis procedures on biofuel selectivity. For this purpose, alumina-supported catalysts containing Zr, Co, and W were prepared using the wet impregnation method. Some physical and chemical properties of the synthesized catalysts were determined through XRD, BET, SEM/EDS, ICP-MS, TGA-DTA, and DRIFTS analysis. The activity test studies revealed that the 5Co-10Zr@MA catalyst, prepared by co-impregnation, exhibited the highest bio-oil conversion (95 %) and the highest iso-paraffin selectivity (93 %). XRD analysis indicated that this catalyst possess the CoAl2O4 structure, indicating the formation of an alloy between alumina and cobalt, thereby enhancing catalytic activity. The reusability tests showed that the 5Co-10Zr@MA catalyst maintained its activity over a time of 3 h. Consequently, the utilization of mesoporous alumina-supported bimetallic catalysts has proven to be successful in the production of biofuels, achieving high conversion and selectivity.

Copper-loaded sustainable MOFs as photocatalysts for dye removal

This work presents the effect of Cu loading, using incipient wetness impregnation method, on sustainably synthesized MIL-100(Fe), NH2-MIL-53(Al), Zr-BDC and NH2-Zr-BDC MOFs and their photocatalytic removal efficiency on target dye, rhodamine B (RhB), from aqueous solutions. Several Cu ratios have been tested, finding that 2 wt% of Cu load becomes optimum in terms of metal distribution and catalytic performance. Powder X-ray diffraction patterns (XRD) showed no difference from the parent supports in the case of MIL-100(Fe), NH2-MIL-53(Al) and Zr-BDC, whereas extra peaks are induced by Cu impregnation in NH2-Zr-BDC. In addition, several techniques indicate that Cu strongly interacts with the MOF in Cu@NH2-Zr-BDC, exhibiting the lowest bandgap of the series, the lowest photoluminescence intensity and a notable predominance of Cu in the oxidation state 2+. The above evidences lead Cu@NH2-Zr-BDC to behave as the most effective catalyst in the removal of RhB, reaching removal efficiency as high as 93 %, being able to efficiently and selectively remove basic dyes from mixed samples, such as RhB and MB, but not for acidic dyes like MO, and also showing a very good performance (46 % photodegradation) in real waste water from Hawassa textile factory, in Ethiopia. Moreover, this catalyst can be recycled 3 times by simple washing and drying. Scavengers test suggested that h+ is the most active species in the photocatalytic degradation.

Surface B-site exsolving double perovskite supported copper use for control the catalytic performance for high-temperature CO-SCR

There is little research on the use of double perovskites (AA'BB'O6) in the CO reduction NO. Therefore, a series of CuX/LCM catalysts which supported CuO on double perovskite were prepared by sol-gel method and initial wet impregnation method. The best activity while preserving the double perovskite structure is found in Cu5/LCM with 5 % Cu. The Cu5/R-LCM catalyst was made by performing a high-temperature exsolution treatment with LCM and loading R-LCM with CuO in order to address the issue of unstable high-temperature activity and low N2 conversion of Cu5/LCM. The findings demonstrate that Cu5/R-LCM has a high N2 selectivity and an excellent conversion rate of NO at high-temperatures. The interaction between Co and Cu (Cu2++Co2+↔Cu++Co3+) on the Cu5/R-LCM catalyst inhibits CuO from being reduced at high-temperatures and exhibits good high-temperature stability. The surface synergistic oxygen vacancies (SSOVs) created by Co and Cu can encourage the dissociation of NO and produce [N] and [O] free radicals. [N] radicals are more likely to form on the surface of Cu5/R-LCM than on Cu5/LCM, and after migrating, they will combine to form N2, improving N2 selectivity. These factors cause Cu5/R-LCM to have superior N2 selectivity and high-temperature catalytic activity than Cu5/LCM.