Loading Of Active Components Research Articles

Accelerated thioanisole oxidation using partially β-brominated Cobalt(II) porphyrin heterogenized within UiO-66 scaffold

Heterogenization of a partially β-brominated cobalt (II) tetraphenylporphyrin complex (CoIITPPBr4) within the cavities of an UiO-66 (UiO stands for Universitetet i Oslo) metal-organic framework (MOF) using bottle-around-ship (BAS) strategy resulted in the formation of highly selective recoverable biomimetic catalyst (CoIITPPBr4@UiO-66). Integrating partial β-bromination with entrapment within the MOF host improved the porphyrin complex's stability and efficiency while preventing its deactivation owing to self-destruction. Under the influence of a heterogenized catalyst with a low active component loading, the selective oxidation of thioanisole (PhSMe) to methyl phenyl sulfoxide (PhSOMe) by hydrogen peroxide (H2O2) in acetonitrile (MeCN) solvent in the presence of imidazole (ImH) co-catalyst and acetic anhydride (Ac2O) activator was expedited significantly with an outstanding conversion (96.01 %) and selectivity (100 %). Also, the utilization of diverse analysis techniques verified the efficacious fabrication, as well as the stability and recyclability of the catalyst after four catalytic cycles.

Preparation of fibrous ceramic-based catalytic membranes by microwave heating and their structural properties and dust and NO removal characteristics

Different drying methods were used to prepare catalytic membranes for the simultaneous removal of dust and NO to explore their effect on the distribution of active components, with the structural properties, filtration performance, catalytic performance, and working mechanism of the preferred prepared catalytic membrane systematically investigated. The results indicated that microwave drying, in contrast to traditional electric drying with blasting, effectively inhibited the migration of the precursor solution to achieve uniform loading of active components, thus endowing the catalytic membrane with excellent catalytic activity. Meanwhile, the pore structure of the fibrous ceramic substrate was not almost affected by the loaded catalyst and still exhibited high porosity. These characteristics contributed to the development of a catalytic membrane with good filtration and catalytic performance, as well as superior adaptable NO concentration and filtration velocity properties. Therefore, fibrous ceramic-based catalytic membranes prepared using microwave assistance offer considerable application prospects for integrated purification of high-temperature flue gases. Furthermore, the removal of dust and NO was determined to follow the Eley–Rideal reaction mechanism and surface filtration mechanism of the residual dust cake, respectively.

Polycarbonate-Based Copolymer Micelles as Biodegradable Carriers of Anticancer Podophyllotoxin or Juniper Extracts.

Podophyllotoxin (PPT) is used in the industrial production of efficient anticancer, antiviral and other drugs. Sinopodophyllum hexandrum or Podophyllum peltatum are natural sources of PPT, but at present they are considered as endangered species. Their PPT content is variable, depending on the growing conditions. Searching for new sources of PPT, some representatives of the genus Juniperus were found to exhibit efficient PPT biosynthesis. However, PPT is highly toxic and poorly soluble in water compound, which limits its clinical applications. In this connection, amphiphilic polymer micelles are considered to be suitable PPT carriers, aimed at increase in water solubility and decrease in toxicity. The present research deals with the evaluation of MPEG-polycarbonate block copolymer micelles loaded with PPT or juniper extracts. The active component-loaded polymer nanocarriers were characterized by dynamic and electrophoretic light scattering, as well as by transmission electron microscopy. The active component loading efficiency and loading capacity were also determined. Highly efficient antiproliferative activity of the loaded micelles was determined in a panel of cancer cell lines. The obtained amphiphilic nanocarriers, loaded with PPT-containing bioactive components, have application in future in vivo preclinical trials of their pharmacokinetics and pharmacodynamics as potential therapeutical agents in the prospective nanomedicine.

Unleashing the high energy potential of zinc-iodide batteries: high-loaded thick electrodes designed with zinc iodide as the cathode.

The realization of high energy is of great importance to unlock the practical potential of zinc-iodine batteries. However, significant challenges, such as low iodine loading (mostly less than 50 wt%), restricted iodine reutilization, and severe structural pulverization during cycling, compromise its intrinsic features. This study introduces an optimized, fully zincified zinc iodide loaded onto a hierarchical carbon scaffold with high active component loading and content (82 wt%) to prepare a thick cathode for enabling high-energy Zn-I2 batteries. The synergistic interactions between nitrogen heteroatoms and cobalt nanocrystals within the porous matrix not only provide forceful chemisorption to lock polyiodide intermediates but also invoke the electrocatalytic effects to manipulate efficient iodine conversion. The ZnI2 cathode could effectively alleviate continuous volumetric expansion and maximize the utilization of active species. The electrochemical examinations confirm the thickness-independent battery performance of assembled Zn-I2 cells due to the ensemble effect of composite electrodes. Accordingly, with a thickness of 300 μm and ZnI2 loading of up to 20.5 mg cm-2, the cathode delivers a specific capacity of 92 mA h gcathode-1 after 2000 cycles at 1C. Moreover, the Zn-I2 pouch cell with ZnI2 cathode has an energy density of 145 W h kgcathode-1 as well as a stable long cycle life.

Selective catalytic oxidation of phenylcarbinol with Fe-doped Cu/SBA-15 catalyst: A study on the synergistic effect of Cu-Fe metals

In this study, Cu, Fe/SBA-15 catalysts were prepared by impregnation method, and a series of characterization were carried out. XRD, physical adsorption and TEM results showed that SBA-15 molecular sieve has a highly ordered two-dimensional hexagonal mesoporous structure, and the loading of active components does not significantly destroy the ordered mesoporous structure of SBA-15. The catalyst with Cu: Fe=2:1 showed the best catalytic performance, and the oxidation yield of phenylcarbinol reached 54 % at 90 °C with DMSO as solvent and TBHP as oxidant for 3 h. Physical and chemical analysis by XPS, DR. UV–vis and H2-TPR showed that Cu-Fe synergistic effect can significantly improve the catalytic performance, the highly dispersed Cu species in bimetallic catalysts were more concentrated on the catalyst surface, which improved the redox performance and electron transfer ability of the catalysts. The above characterization results provide strong evidence to explain the difference of catalytic activity.

ZrO2-MoO3/modified lotus stem biochar catalysts for catalytic aquathermolysis of heavy oil at low-temperature

Aquathermolysis is one of the thermochemical reactions in the heavy oil thermal recovery process. The key issue, i.e., the high temperature required by aquathermolysis, can be reduced by the involvement of catalysts. However, the effective working temperature of catalysts is still above 240 ℃, which needs to be further reduced to enhance energy efficiency. Considering that biochar has a high specific surface area, abundant functional groups, a wide temperature window, and can be easily modified, a series of ZrO2-MoO3-based catalysts loaded on raw or three modified lotus stem biochar were studied to investigate heavy oil catalytic viscosity reduction at low temperatures. Physicochemical properties of catalysts were investigated by a variety of characterization methods. The performance of four kinds of catalysts and the influence of reaction conditions (temperature and time) on aquathermolysis were evaluated. The results showed that silane coupling agent KH570 modified biochar (KH570-MLSB) has a higher specific surface area and more functional groups, which help the loading of active components and the dispersion in heavy oil. ZrO2 can form coordination compounds with S atoms in C-S, which greatly weakens the bond energy of C-S and reduces the activation energy of the aquathermolysis. The coordination bonding energy with S of Mo is weaker than that of Zr. The main role of MoO3 is to inhibit the formation of coke. Therefore, catalyst Ⅳ, which consists of KH570-MLSB, ZrO2, and MoO3, has the best catalytic effect at 200 ℃. In addition, the optimum reaction time of the catalyst is 24 h.

Experimental study on coal-fired flue gas HCl removal by injecting adsorbent into flue duct

Abstract Adsorbent injection into flue ducts is an effective technology for controlling gaseous pollutant in coal-fired power plants. This study proposed a new technique of injecting dechlorinater into flue duct for HCl removal in order to realize the wet flue gas desulfurization (WFGD) wastewater sequestration and upgrade the gypsum quality, known as the source dechlorination method. Four alkaline-based adsorbents of CaO, Ca(OH)2 + 5 % NaOH, ethanol-modified CaO, and NaHCO3 were developed and investigated in a pilot scale 6 kW coal-fired circulating fluidized bed (CFB) combustion system for capturing flue gas HCl. The physical and chemical properties of the adsorbents were characterized to explore the reaction mechanisms affected by the adsorbent size and its distribution, active component loading, micro-structure, morphology, and crystal structure. The influences of the injection amount, resident time and flue gas temperature on the HCl removal efficiency were carried out, the dechlorination mechanism of the ethanol-modified CaO were discussed. The distribution of flue gas chlorine species across the air pollutant control devices (APCD) were obtained. This study provides basis for developing the technology of injecting dechlorinater into flue gas for HCl removal.

Effect of Metal Complexing on Mn–Fe/TS-1 Catalysts for Selective Catalytic Reduction of NO with NH3

TS-1 zeolite with desirable pore structure, an abundance of acidic sites, and good thermal stability promising as a support for the selective catalytic reduction of NO with NH3 (NH3-SCR). Herein, a series of Mn-Fe/TS-1 catalysts have been synthesized, adopting tetraethylenepentamine (TEPA) as a metal complexing agent using the one-pot hydrothermal method. The introduced TEPA can not only increase the loading of active components but also prompts the formation of a hierarchical structure through decreasing the size of TS-1 nanocrystals to produce intercrystalline mesopores during the hydrothermal crystallization process. The optimized Mn-Fe/TS-1(R-2) catalyst shows remarkable NH3-SCR performance. Moreover, it exhibits excellent resistance to H2O and SO2 at low temperatures. The characterization results indicate that Mn-Fe/TS-1(R-2) possesses abundant surface Mn4+ and Fe2+ and chemisorbed oxygen, strong reducibility, and a high Brønsted acid amount. For comparison, Mn-Fe/TiO2 displays a narrower active temperature window due to its poor thermostability.

3D spiderweb-like nanowire networks loading single-atom catalysts in capillary array as high-efficiency microreactor

Rapid fluid transport and high reaction efficiency are known as irreconcilable indicators for designing high-performance monolithic microreactors. Here, proceeding from microstructure design and single-atom catalysts (SACs) utilization simultaneously, we developed 3D spiderweb-like nanowire networks in wood capillary array owning high permeability integrated with successfully synthesized SACs as high-efficiency microreactor for organic pollutant removal from water. The 3D spiderweb-like nanowire networks could be obtained by noncovalent and physical entanglement interactions of ultralong and flexible PEG113-b-P4VP104 worm-like micelles forming loosened micro-aerogel in the wood capillary. Abundant nanowire networks in straight microchannels array allow vast quantities of catalyst active component loading sites and greatly increase contact reaction efficiency. Meanwhile, the grid-like porous structure of the nanowire networks preferably maintains good permeability of the wood capillary array. Furthermore, strong coordination interaction of pyridine in P4VP block and confinement effect from core-shell structured worm-like micelles afford uniformly distributed SACs with high density. As a proof of concept, we demonstrate an integration of unique microstructure from 3D spiderweb-like nanowire networks in wood capillary array and well dispersed Pd-N4/Fe-N4 SACs enables high removal efficiency for methylene blue and fast mass transfer for water. Importantly, this work provides a facile and scalable method for atomically dispersed catalysts, paving the way for designing high-performance microreactors in other potentially important reactions.

Catalytic Ozonation for Effective Degradation of Coal Chemical Biochemical Tail Water by Mn/Ce@RM Catalyst

An Mn/Ce@red mud (RM) catalyst was prepared from RM via a doping–calcination method. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used to characterize the surface morphology, crystal morphology, and elemental composition of the Mn/Ce@RM catalyst, respectively. In addition, preparation and catalytic ozonation conditions were optimized, and the mechanism of catalytic ozonation was discussed. Lastly, a fuzzy analytic hierarchy process (FAHP) was adopted to evaluate the degradation of coal chemical biochemical tail water. The best preparation conditions for the Mn/Ce@RM catalyst were found to be as follows: (1) active component loading of 3%, (2) Mn/Ce doping ratio of 2:1, (3) calcination temperature of 550 °C, (4) calcination time of 240 min, and (5) fly ash floating bead doping of 10%. The chemical oxygen demand (COD) removal rate was 76.58% under this preparation condition. The characterization results suggested that the pore structure of the optimized Mn/Ce@RM catalyst was significantly improved. Mn and Ce were successfully loaded on the catalyst in the form of MnO2 and CeO2. The best operating conditions in the study were as follows: (1) reaction time of 80 min, (2) initial pH of 9, (3) ozone dosage of 2.0 g/h, (4) catalyst dosage of 62.5 g/L, and (5) COD removal rate of 84.96%. Mechanism analysis results showed that hydroxyl radicals (•OH) played a leading role in degrading organics in the biochemical tail water, and adsorption of RM and direct oxidation of ozone played a secondary role. FAHP was established on the basis of environmental impact, economic benefit, and energy consumption. Comprehensive evaluation by FAHP demonstrated that D3 (with an ozone dosage of 2.0 g/H, a catalyst dosage of 62.5 g/L, initial pH of 9, reaction time of 80 min, and a COD removal rate of 84.96%) was the best operating condition.

Selective oligomerization of isobutylene in mixed C4 catalyzed by supported Fe(NO3)3/β catalyst

AbstractBACKGROUNDMethyl tert‐butyl ether (referred to as MTBE) is harmful to the environment and hence its use is limited in China. To avoid the waste of isobutylene as MTBE raw material and improve the utilization rate of isobutylene in mixed C4 fraction, supported Fe(NO3)3/β molecular sieve catalysts with different active components were prepared by the equal volume impregnation method. The catalysts were analyzed by X‐ray diffraction (XRD), Thermogravimetric analysis (TG), Temperature programmed desorption of NH3, Brunauer–Emmett–Teller analysis and scanning electron microscopy, and the catalytic performance of catalysts with mixed C4 fractions as raw materials and different active component loadings for selective oligomerization of isobutylene was investigated in a fixed bed reactor.RESULTSThe results show that the catalyst has the best catalytic performance when the active component loading was 6%, the reaction temperature was 60 °C, the reaction pressure was 1 MPa and the reaction space velocity was 1.5 h−1.CONCLUSIONThe conversion rate of isobutylene was >90%, the selectivity of C8 olefin was ≈80% and there was almost no loss of n‐butene. © 2021 Society of Chemical Industry (SCI).

Simultaneous Desulfurization and Denitrification Using La-Ce-V-Cu-ZSM-5 Catalysts in an Electrostatic Precipitator.

Different catalysts were loaded onto the collecting plate of an electrostatic precipitator to achieve the simultaneous removal of multiple pollutants from coal-fired gas. The synergistic desulfurization and denitrification effect of the catalyst and the effect of corona discharge on the activity of the catalyst were studied. The La(6%)–Ce(8%)–V(7%)–Cu(8%)–ZSM-5 catalyst prepared by successive impregnation methods had the optimum simultaneous desulfurization and denitrification efficiency at a roasting temperature of 600 °C. The desulfurization and denitrification rates reached 97.09 and 83.30%, respectively. BET and SEM characterization results showed that the loading of active components and additives improved the pore structure of the molecular sieve, which contributed to the high stability of the catalyst’s internal structure and large surface area, as well as better desulfurization and denitrification efficiency. Corona discharge can significantly improve the catalytic effect.

Modification of Y‐Zeolite with Zirconium for Enhancing the Active Component Loading: Preparation and Sulfate Adsorption Performance of ZrO(OH)2/Y‐Zeolite

AbstractNowadays, several techniques have been utilized to remove sulfate from industrial sewage. The method using ZrO(OH)2 to adsorb sulfate is highly efficient and environmentally friendly, however, nano‐powdered ZrO(OH)2 is hard to be recycled owing to its great loss in the adsorption process, which brings enormous difficulties to industrial applications. In this research, to prevent adsorbents from losing, Y‐zeolite was modified with zirconium, including the incorporation of zirconium as heteroatoms into zeolite frameworks and ion‐exchange of Zr4+ into the cages of zeolite, and then used as carrier to load ZrO(OH)2 to fabricate adsorbent via the stepwise impregnation treatment. The as‐prepared supported adsorbent ZrO(OH)2/Y‐zeolite has a high SO42− adsorption capacity, a strong adsorption selectivity to SO42− and good adsorption‐regeneration circulation performances. The saturated SO42− adsorption capacity of 284.22 mg/g can be obtained under the following adsorption conditions: SO42− concentration of 10 g/L, the pH value of 1.5, the temperature of 25 °C. After five adsorption‐regeneration circulations, its adsorption capacity has decreased only about 10%. The adsorption‐ desorption of sulfate over ZrO(OH)2/Y‐zeolite adsorbent proceeds according to the ion‐exchange mechanism between sulfate and the surface hydroxyl groups.

Adsorbent from Rice Husk for CO2 Capture: Synthesis, Characterization, and Optimization of Parameters

In the present work, adsorbents were prepared from rice husk in order to capture CO2 from a flue gas stream. Various pretreatment processes such as desilicalization, chemical activation, and K2CO3 impregnation were followed to prepare the adsorbents. The physico-chemical characterization of the adsorbents was performed in detail in an elaborated way. A fixed-bed reactor was used to measure the CO2 capture capacity of the in-house developed adsorbents. The effect of various process parameters such as adsorption temperature, moisture content, and loading of active component on CO2 adsorption capacity was studied, and results were compared with a commercially available activated carbon. The maximum adsorption capacity observed for 20K-ARH adsorbent was as high as 67 g of CO2/kg sorbent. The effect of water on CO2 adsorption was critically examined, and formation of KHCO3 was observed in the presence of water during the adsorption process. The optimum operating conditions for the maximum removal of CO2 from a...

Thin-film photovoltaic devices incorporating low-bandgap push-pull molecules dispersed in passive polymeric matrices

Active layers in many thin-film organic photovoltaic devices (OPVs) contain light-absorbing polymers that serve as electron donors, mixed with appropriate electron acceptors. In principle, the polymers can be replaced by small molecules with suitable bandgaps, which offer multiple advantages, including well-defined structures and methods of synthesis and purification that provide uniform samples. However, such materials often undergo separation of phases and crystallization, so making long-lived films that remain smooth, homogeneous, flexible, and transparent is not easy. We have found that effective OPVs can be made by dispersing mixtures of low-bandgap push–pull small molecules as electron donors and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as electron acceptor in matrices of optoelectronically passive conventional polymers, including polystyrene, poly(methyl methacrylate), poly(vinyl chloride), poly(ethylene glycol), and poly(dimethylsiloxane). By varying the identity of the matrix, its molecular weight, the loading of active components, and the conditions of annealing, we have produced efficient OPVs from components that would otherwise have undergone phase separation and crystallization, leading to poor performance. Layers with up to 35% matrix were found to be effective and could be fabricated at room temperature by simple processes. To probe the role of the polymers as dispersants, morphologies of composite films were examined by atomic force microscopy and electron microscopy. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017

The utilization of hydroxyapatite-supported CaO-CeO2 catalyst for biodiesel production

The study investigated the effect of a bimetallic supported catalyst in biodiesel production. Calcined waste bone derived hydroxyapatite (HAP), a solid waste from animal, was served as the support for CaO-CeO2 catalyst. Various characterization techniques such as FT-IR, BET, SEM-EDS, CO2-TPD and XRD analysis were used to analyse the activity of this heterogeneous catalyst. The effect of main parameters in preparation process such as calcination temperature and active component loading on catalyst performance were discussed to obtain the optimal preparation conditions. Under the optimal reaction conditions (11wt.% dosage of 30%CaO-CeO2/HAP-650 catalyst and 9:1 methanol to oil molar ratio at 65°C for 3h) the highest biodiesel yield of 91.84% was obtained. Stability test indicated that the yield (84.4%) of fatty acid methyl ester was produced after 8 re-used cycles due to the low leaching of catalyst components. The experimental results showed that biodiesel production cost might be lowered while producing relatively high yield at the present of long life-span catalyst.

Effects of Reaction Conditions on Methanol Produced to Dimethyl Ether

Dimethyl ether can be obtained by using methanol as feedstock and MgO/HZSM-5 as catalysts. The effects of reaction conditions, such as loading of active components, weight hourly space velocity, reaction temperature, and Si-Al molar ratio, on methanol produced to dimethyl ether are mainly discussed. The experimental results indicate that it does not affect the skeleton structure of HZSM-5 molecular sieve too much with adding MgO; therefore, methanol’s conversion reaches the maximum value when the weight hourly space velocity and the reaction temperature are 2 h−1 and between 280 and 320°C, respectively. For β-zeolite and ZSM-5 zeolite, methanol’s conversion increases with the increase of Si-Al molar ratio from 26 to 100 and from 30 to 80, respectively. The article aims to find the best conditions for methanol produced to dimethyl ether.

Reaction Mechanism and Kinetics of Methanol Produced to Dimethyl Ether

Dimethyl ether can be obtained by using methanol as a feedstock and CNM-3 and MgO/HZSM-5 as feedstock. The effects of loading of active components on methanol produced to DME are mainly discussed. The experimental results indicate that it does not affect too much to the skeleton structure of HZSM-5 molecular sieve with adding MgO. When reaction temperature, ratio of methanol and ethanol, and weight hourly space velocity are between 200 and 300 °C, 3:1, and 4 h−1, the reaction equation of the kinetics model is . Its activation energy and pre-exponential factor are 16.650 KJ/mol and 0.385 s−1, respectively.

Porous zirconium phosphate supported tungsten oxide solid acid catalysts for the vapour phase dehydration of glycerol

Solid acid catalysts containing WOx/ZrP with varying the active component loading (5–40wt%) on porous ZrP support have been investigated for the vapour phase dehydration of glycerol to acrolein. The catalyst containing 30wt% WOx/ZrP has shown high selectivity to acrolein (about 82%) with a total conversion of glycerol at 300°C in the presence of water. The calcined catalysts were characterized by X-ray diffraction, pore size distribution, FT-IR, UV-DRS, pyridine absorbed FT-IR and NH3-temperature programmed desorption to elucidate the structural and acidic properties of the catalysts. The XRD results suggest that WOx is found to be present in a highly dispersed state at lower loadings (<30wt%) and crystalline WOx at higher loadings. NH3-TPD and FT-IR results of adsorbed pyridine suggest that the total acidity and number of Brønsted acidic sites are found to increase with WO3 loading on the support. Further, there is no significant change of acidity was noticed at higher loadings. The conversion of glycerol and the selectivity toward acrolein mainly depend on the fraction of moderate acidic sites and Brønsted acidic sites. The Glycerol dehydration functionalities are explained in terms of the acidity and structural properties of WOx/ZrP catalysts. In addition, the positive effect due to addition of air to N2 feed flow suppresses the coke formation on the surface of catalyst was also investigated during dehydration reaction.

Integrative Chemistry-Based Generation of Novel Three Dimensional Macrocellular Carbonaceous Biofuel Cell

ABSTRACTHere we report the first membrane-less biofuel cell made by using three-dimensional carbonaceous foam electrodes. We first developed a new synthetic pathway to produce a new carbonaceous foam electrode material with increased porosity both in the meso and macroporous scale. We proved that by increasing the porosity of our three-dimensional foams we could increase the current density of our modified electrodes. Then, by choosing the right combination of enzyme and mediator, and the right loading of active components, we achieved unprecedentedly high current densities for an anodic system. Finally, we combined the improved cathode and anode to build a new membrane-less hybrid enzymatic biofuel cell consisting of a mediated anode and a mediator-less cathode.