Catalyst Mixture Research Articles

Influence of Solid Alkaline Photocatalysts Irradiated with UV Light on Fuel Properties of Palm Oil Biodiesel.

TiO2 nanoparticles are full of porosity that can be impregnated with a strong alkaline catalyst CH3ONa to form a TiO2/CH3ONa catalyst. TiO2 of the anatase phase, which is a semiconductor material, has been a prominent photocatalyst due to its excited photocatalyst activity, chemical and biological stability, and nontoxicity. The CH3ONa compound has been widely used as a catalyst for transesterification. Although the synthesized photocatalyst TiO2 powder with CH3ONa is anticipated to greatly enhance the transesterification efficiency, leading to improving biodiesel properties, relevant studies have not been found. After the photocatalyst was prepared, a reactant mixture of palm oil, methanol, and heterogeneous catalyst TiO2/CH3ONa was illuminated by ultraviolet (UV) light from light-emitting diode (LED) lamps. The experimental results revealed that the formation of fatty acid methyl esters was significantly increased to 98.4% with ultraviolet-light illumination for the molar ratio of methanol/palm oil equal to 6 and 3 wt % catalyst addition. The decrease of the catalyst amount to 2 wt % resulted in a slight decrease of the fatty acid methyl esters to 97.06 wt %. The lowest kinematic viscosity and acid value and the highest distillation temperature, heating value, and cetane index were observed under the above reaction conditions. The distillation temperature and cetane index were increased while the acid value was decreased under ultraviolet illumination on the reactant mixture. Consequently, the optimum preparing conditions for biodiesel production were 6 and 3 wt % for the molar ratio of methanol/palm oil and catalyst addition under UV-light irradiation.

Electrocatalytic Decomposition of Lithium Oxalate-Based Composite Microspheres as a Prelithiation Additive in Lithium-Ion Batteries.

In conventional lithium-ion batteries (LIBs), the active lithium from the lithium-containing cathode is consumed by the formation of a solid electrolyte interface (SEI) at the anode during the first charge, resulting in irreversible capacity loss. Prelithiation additives can provide additional active lithium to effectively compensate for lithium loss. Lithium oxalate is regarded as a promising ideal cathode prelithiation agent; however, the electrochemical decomposition of lithium oxalate is challenging. In this work, a hollow and porous composite microsphere was prepared using a mixture of lithium oxalate, Ketjen Black and transition metal oxide catalyst, and the formulation was optimized. Owing to the compositional and structural merits, the decomposition voltage of lithium oxalate in the microsphere was reduced to 3.93 V; when being used as an additive, there is no noticeable side effect on the performance of the cathode material. With 4.2% of such an additive, the first discharge capacity of the LiFePO4‖graphite full cell increases from 139.1 to 151.9 mAh g-1, and the coulombic efficiency increases from 88.1% to 96.3%; it also facilitates the formation of a superior SEI, leading to enhanced cycling stability. This work provides an optimized formula for developing an efficient prelithiation agent for LIBs.

Effect of zeolites on the alkylation of aromatics with alkanes using a Pd nanoparticle/solid acid cooperative catalytic system

The direct alkylation of benzene with alkanes is an effective method for alkylbenzene production. Our group previously discovered that a mixture of supported Pd nanoparticles and solid acids effectively promoted the alkylation of benzene with alkanes. Herein, the alkylation of toluene with n-heptane was catalyzed by physical mixture of H-mordenite and Pd nanoparticles supported on hydrotalcite to afford the corresponding C7 alkylation product with 87% selectivity and 14% toluene conversion. The reaction slightly proceeded in the absence of Pd nanoparticles or H-mordenite, indicating cooperative catalysis by the two different solid catalysts. Moreover, the high stability of the Pd nanoparticles on hydrotalcite was confirmed via reuse experiments and transmission electron microscopy (TEM) analysis. The catalyst mixture was reused at least three times without any loss of product yield, and after three reuses, TEM analysis revealed that the size of the Pd nanoparticles following the initial catalytic reaction was similar to that of the catalyst. Scanning transmission electron microscopy with energy dispersive spectroscopy (STEM-EDS) analysis of the recovered catalyst mixture revealed the preservation of Pd nanoparticles on the hydrotalcite surface, as well as the close positioning of the two different catalyst particles, thus suggesting interparticle hydrogen transfer. The structure of the solid acid strongly affected the alkylation product selectivity. For example, H-mordenite showed high selectivity for the n-heptane alkylation product with a C7 alkyl chain, whereas the selectivity changed with other zeolites. This cooperative catalytic system can be applied to the alkylation of other substituted benzenes, such as xylenes and phenols, with good selectivity toward the desired alkylation product.

Effect of the U-Shaped Cavity of Conformationally Flexible Chiral Lewis-Acidic Boron-Based Catalysts in Multiselective Diels-Alder Reactions.

The effect of the U-shaped cavity of conformationally flexible chiral Lewis acidic boron-based catalysts in multiselective Diels-Alder reactions was investigated. The U-shaped catalysts can recognize substituents at the terminal acetylene moiety of propynal based on steric factors and can also recognize alkyne and alkene substrates based on the match/mismatch between the catalysts and substrates. Moreover, even in a mixture of different catalysts and substrates, the desired competitive reactions can proceed multiselectively. This proof-of-concept study should contribute to the development of artificial enzyme-like catalysis in vitro.

Fe[sbnd]N[sbnd]C single-atom peroxymonosulfate activator based on natural diatomite: Dispersion and strengthening mechanism

Iron single atom catalysts were supported on diatomite via Zif-8 precursor and atmosphere induction strategy. The introduction of diatomite makes it possible to regulate the pore structure and active sites of composite catalyst, and the ability of FeNC/diatomite (FeNC/DA) activated peroxymonosulfate (PMS) to degrade bisphenol A (BPA) was 11.8 times and 9.6 times that of pure catalyst and physical mixture. Furthermore, the carbon material forms a composite active center with iron single atoms and achieves efficient PMS activation. The density functional theory calculation results proved that the FeN4 center could grow oxygen-oxygen bond length to enhance PMS self-decomposition. Besides, tetravalent iron, superoxide radicals and singlet oxygen participate in the degradation process of BPA, and the possible degradation pathways of BPA in the FeNC/DA/PMS system were also speculated. Our work provides a sight for the combination of natural minerals and monatomic catalysts to obtain an efficient, stable and potential persulfate activator.

Two-stage thermocatalytic conversion of waste XLPE to diesel-like fuel

Cross-linked polyethylenes (XLPE) are not preferred in industrial pyrolysis applications and mechanical recovery methods due to great thermochemical resistance to heat and deformation. The studies on pyrolysis of XLPE up to 600?C on obtaining fuel have generally yielded high levels of wax and have not been of interest to the energy sector. In this study, two-stage pyrolysis of XLPE was carried out catalytically and also without catalyst (thermal, T- -pyr) under 500?C with heating rates of 5 and 10?C min-1. In the pyrolysis experiments, three different catalytic studies were performed by adding MCM- -41 + HZSM-5 catalyst mixture to the polymer phase only (PPC-pyr), by filling Cu(I)-MAS + HZSM-5 catalyst mixture to the gas outlet column only (GPC- -Pyr) and adding catalyst mixtures in both polymer phase and gas phase (MPC- -pyr). The highest diesel-like fuel (91.40 wt. %) was obtained in multiphase catalytic pyrolysis experiments at 460?C with a heating rate of 5?C min-1. The calorific value, kinematic viscosity, density, flash point and cetane number of the fuel were found as 45.97 MJ kg-1, 2.72 cSt, 832.5 kg m-3, 57 and 59?C, respectively. The results of the two-stage catalytic cracking and the heating rate profile will be a guide for industrial pyrolysis applications. The simple feasibility for industrial applications showed that it would be a very profitable investment.

A highly durable catalyst system for hydrogen production from dimethyl ether

This paper describes a highly stable and selective catalyst mixture of γ-Al2O3 and In2O3/ZrO2 for hydrogen production from dimethyl ether.

Promoting AEM Water Electrolyzer Performance and Reproducibility by Tumbler Milling of Ni3fe-LDH OER Catalyst

Anion exchange membrane water electrolysis is an attractive clean energy technology for producing hydrogen for energy storage, transport 1,2 and numerous other applications. Rational choice of highly active and stable catalysts as well as the proper design of catalyst layers are crucial to achieve technical relevance of electrolyser systems. The establishment of clear understanding of optimal catalyst treatment and methods of implementation are key steps towards optimized electrolyzer performance and durability. One aspect of catalyst performance in catalyst layers is the catalyst size distribution. A multimodal size distribution of catalyst particles or agglomerates can jeopardize the layer homogeneity and thus electrode performance.In this work, the effect of high-energy ball tumbling milling on the promising Ni3Fe-LDH OER catalyst followed by catalyst dispersion control was correlated to the microstructure of the catalyst layer, the achieved catalyst activity and utilization, and the resulting single cell performance and stability. Physico-chemical characterization confirmed the stable layered double hydroxide structure of the catalyst. By milling, a 300-fold reduction of catalyst agglomerate size, and an 8.8-fold increase of the geometrical surface was achieved. The optimized solvent compositions effectively increased the catalyst ink stability. We found that a significantly decreased catalyst agglomerate size resulted in very homogeneous mixtures of catalyst and ionomer. By tailoring the electrode structure design, lower internal electronic resistances of the electrodes, decreased charge-transfer resistances (Rct) of the membrane electrode assembly, and stable single cell durability of 1000 h with a minor degradation rate of 57 µV h-1 were accomplished.This work presents a facile and scalable approach of NiFe-LDH catalyst treatment and dispersion control and provides a guideline to follow for further electrode development and increased AEM water electrolyzer performances. References (1) Hydrogen Applications. Hydrogen Europe. 2020. https://hydrogeneurope.eu/hydrogen-applications (accessed Jan 7, 2022).(2) Vincent, I.; Bessarabov, D. Low Cost Hydrogen Production by Anion Exchange Membrane Electrolysis: A Review. Renew. Sustain. Energy Rev. 2018, 81 (August 2016), 1690–1704. https://doi.org/10.1016/j.rser.2017.05.258. This work has been performed in the frame of the CHANNEL project. This project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (now Clean Hydrogen Partnership) under grant agreement No 875088. This Joint undertaking receives support from the European Union's Horizon 2020 Research and Innovation program, Hydrogen Europe and Hydrogen Europe Research.

Kinetic Study of the Aluminum–water Reaction Using NaOH/NaAlO2 Catalyst for Hydrogen Production from Aluminum Cans Waste

The presence of oxide layers covering the surface of aluminum is known to impede the hydrogen production reaction. These oxide layers can be broken by adding catalysts and increasing the aluminum-water reaction temperature. Common catalysts used are alkaline catalysts that are capable of achieving high hydrogen production rates in a short time at lower temperatures, while intermediate temperatures of above 50 °C can accelerate the hydration reaction of the oxide layer. Herein, the mixture of NaOH and NaAlO2 catalysts was employed to attain a stable NaAlO2 solution and continuous reaction of NaOH and aluminum. This research analyzes the influence of temperature between 32 and 80 °C on the aluminum, 0.3 M NaOH and 0.001 M NaAlO2 catalysts solution at atmospheric pressure. All solutions produces a similar hydrogen yields and rate. Solutions containing NaAlO2 indicate reverse reaction that surpressing the Al(OH)3 precipitation. Residue from the reaction is investigated using X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), and Scanning Electron Microscope (SEM). The volume of hydrogen produced is evaluated using a mathematical mass reduction and shrinking core model. The rate of hydrogen production depends largely on the aqueous solution's temperature, with an activation energy of 47.4 kJ/mol. Based on the findings, it is readily apparent that the reaction only produced gibbsite and bayerite, with gibbsite and bayerite being dominant at 32–70 °C and 80 °C, respectively. The mass reduction model fits well with the present results with only an average 5.1 mL deviation, whereas the shrinking core model generally tends to result in underestimated values with an average deviation of 23.9 mL. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

PERFORMANCE PROPERTIES OF MARINE FUEL DERIVED FROM SECONDARY POLYMER RAW MATERIALS

The article substantiates the need to determine the operational properties of shipping fuel obtained from secondary polyolefin (HDPE and PP) raw materials by catalytic pyrolysis. It is proposed to evaluate the operational properties of fuel for shipping – marine gasoil (MGO) by the value of the cetane index (CI, unit), H:C ratio, working heat of combustion (Q, MJ/kg). In view of the scheme of catalytic pyrolysis of polymeric raw materials proposed by us, which consists of two stages (I stage - the course of reactions on a mixture (1:1) of zeolitecontaining catalysts Zn-H-ZSM-5/Fe-H-ZSM-5; II stage – the course of reactions on the NiH-ZSM-5 catalyst), it is necessary to determine after each stage of the process the quality indicators of the reaction products (fractions with boiling points of -360(380) °С) given above. Also, additionally, we determined the quality indicators for the fractions obtained on the H-ZSM-5 industrial catalyst. The proposed research program, on the one hand, allows to determine the efficiency of the pyrolysis process with the selected catalysts in comparison with industrial technology, on the other hand, it will allow to adjust the process in the direction of obtaining a final product of a quality level that meets the requirements for MGO presented in ISO 8217:2017. The conducted studies showed that by the value of CI (48-50 units) and ν 40 (2,8–3,1 mm²/s) the fractions with boiling points of 180–360(380) °С, which were obtained by pyrolysis of polymer raw materials according to the two-stage technology proposed by us (on Zn-H-ZSM-catalysts 5/Fe-H-ZSM-5, Ni-H-ZSM-5) can be attributed to the brands of distillate marine fuels DMA, DFA, DMZ, DFZ (ISO 8217:2017). These fractions are also characterized by a high Н:C ratio (for HDPE – 1.62; for PP – 1.64) and working heat of combustion (for HDPE – 44.0 MJ/kg; for PP – 44.3 MJ/kg), which makes it possible to use them as fuels for shipping.

Study on lightening of coal tar with metal oxide supported γ-Al2O3 catalyst

In this experiment, a fixed bed of pyrolysis was used to conduct pyrolysis with coal and a mixture of coal and catalyst, and the distribution and composition of tar products were studied. The pyrolysis of raw coal was carried out at different temperatures and at different constant temperature times, and the effects of pyrolysis temperature and constant temperature pyrolysis time on tar product formation from raw coal pyrolysis were studied. γ-Al2O3 was used as the carrier, and 4 kinds of alkaline earth metal oxides (MgO, CaO, SrO, BaO), 3 kinds of subgroup metal oxides (Fe2O3, Co2O3, NiO) and 5 kinds of VIII metal oxides (Cr2O3, MnO2, CuO, ZnO, MnO2) were selected as active components. The supported γ-Al2O3 catalyst was prepared by the method of equal volume impregnation and roasting in a muffle furnace. The γ-Al2O3 catalyst was characterized by means of XPS, BET and SEM, and the mechanism of the mixed pyrolysis of coal with different metal oxide supported catalysts to generate tar was studied. The results showed that: (1) under the conditions of 450 °C, 500 °C, 550 °C and 600 °C, the maximum tar yield was 0.32 g at 600 °C, and the tar yield was higher at constant temperature for 15 min than at final temperature of 600 °C, with an increase of 15.63%. (2) Fe2O3/γ-Al2O3 catalyst resulted in the highest tar yield of 0.75 g, which was 134.38% higher than that of coal pyrolysis. (3) From the increase of light oil and phenol oil and the decrease of anthracene oil and asphalt, Co2O3/γ-Al2O3, Fe2O3/γ-Al2O3 and Cr2O3/γ-Al2O3 can improve the tar quality better.

Click chemistry of PMHS for fabrication of robust, transparent and hydrophobic silicone resin coating on wood substrate at room temperature

Based on click chemistry of poly(methylhydrogen)siloxane (PMHS), an environment-friendly method was proposed for in-situ fabrication of robust, transparent, UV-resistant and hydrophobic silicone resin coating (SRC) at room temperature by simply brushing a mixture of PMHS, tetramethyltetravinyl cyclotetrasiloxane (V4), and Karstedt catalyst on wood surface. The mechanism for click chemistry of PMHS and the continuous curing characteristic of SRC was discussed based on the characterization of SRC by FTIR and XPS. The effects of the mass ratio of PMHS to V4 and curing time on the properties of SRC and the modified wood were investigated. Results showed that SRC with the mass ratio of PMHS to V4 of 5:1 possessed the best mechanical stability, and the mechanical stability increased with curing time and temperature. SRC improved significantly the hydrophobicity and water-repellency of wood by increasing the water contact angle from 27.2° to 123.1° and decreasing the water absorption rate from 103 % to 16 %. SRCs showed excellent transparency with an average transmittance of 92.3 % at 400–1100 nm. The UV resistance of SRC was 6 times higher than that of varnish coating. The click chemistry of PMHS will find great application in rapid fabrication of functional coatings on wood surface by using PMHS and any vinylated reagent or micro-/nano-particles.

Fabrication of catalyst layer for proton exchange membrane water electrolyzer: I. Effects of dispersion on particle size distribution and rheological behavior

The catalyst layers of proton exchange membrane water electrolyzer are generally made by coating ink mixtures of catalyst and ionomer to the membrane. The particle size and stability of such inks are crucial to the formation of the catalyst layer's microstructure and overall cost. In this paper, the characteristics and stability of iridium oxide inks are investigated. The effects of inks dispersed by sonication and ball-milling on the particle size distribution, zeta potential, and viscosity of the catalyst inks are investigated. For both dispersion methods, it is found that increasing the dispersion time and strength effectively reduces the average particle size as expected. The inks prepared by ball-milling tend to have narrower and smaller size distribution than those by sonication. The rheological behavior of these inks is found to be slightly non-Newtonian. Ball-milling appears to increase the ink viscosity. A dual-dispersion technique that combines both dispersion steps is developed in the present study. The inks made with this procedure yield smaller size distributions than those with single dispersion, thus a higher specific catalyst area that can reduce catalyst loading and cost. These inks are also found to have a long shelf life remaining homogeneous.

CuO–TiO2 pilot-plant system performance for solar photocatalytic hydrogen production

The main goal of the present study was to explore photocatalytic performance of the TiO2–CuO mixture, for solar to hydrogen conversion at pilot plant scale under two different irradiation conditions (sunny and partly cloudy), focusing on high-temperature pretreatment of the catalyst mixture to try to improve TiO2 doping with copper. P25–TiO2 and commercial CuO were used with different amounts of Cu (2 wt% or 7 wt% Cu) calcined at 200–400 °C during several hours. Catalysts were tested at pilot plant scale using solar compound parabolic collectors, with glycerol as the sacrificial agent. The photocatalyst prepared after heating at 200 °C for 3 h and with 7 wt% Cu, resulted in higher hydrogen production than under the other heating conditions, and results were slightly better (5–10%) than the reference values with the untreated catalysts. Photocatalytic efficiency was slightly lower at the higher calcination temperature (400 °C). CO2 production and formation of formate and glycolate clearly demonstrated glycerol photoreforming. The Cu from the calcined catalyst remaining on the solid was significantly less (2.5%) than on the non-calcined catalyst (4.2%), with an important fraction of lixiviated copper and copper deposition on the reactor walls. This is a critical drawback that must be considered for large-scale applications.

Cu3Si formed by vacuum evaporation deposition enhances hydrogenation of silicon tetrachloride

The efficient conversion of SiCl4 to SiHCl3 still presents considerable challenges for the Siemens process. The enhancement of solid-solid interaction between catalyst and silicon particles in hydrogenation of SiCl4 is viewed as a top priority. In this study, CuCl catalyst and silicon particles mixture heated at the vacuumized tube bomb reactor is found to be an effective pretreatment strategy for obtaining excellent catalytic performance as much as 21.2% under the optimum conditions. The vacuum evaporation deposition is favorable for the deposition uniformly of gaseous CuCl on the surfaces of silicon particles and the formation of Cu3Si. The moderate temperature and time of the vacuum evaporation deposition pretreatment will promote the growth of copper compounds and shorten the induction period of SiCl4 hydrogenation reaction. When CuCl and free copper of the pretreated sample are dissolved by NH4OH, the SiCl4 conversion still maintains 19.8%. Cu3Si is employed as the active phase expresses good catalytic performance where the conversion of SiCl4 is positively correlated with the content of Cu3Si.

Optimize the Properties of Carbon Nanotubes Synthesized using a Microwave Oven

In this paper, carbon nanotubes (CNT) are synthesized using the microwave oven method, which offers several advantages, including a simple, quick, inexpensive, and solvent-free growing method. To produce CNT, a mixture of graphite and ferrocene catalysts had to be flattened inside a microwave oven for five seconds at room temperature. CNT was produced using various ratios of graphite and ferrocene, and analyses indicated that a 70:30 graphite/ferrocene ratio produced better nanocrystalline CNT. To optimize CNT properties, five processes of purification were used to dispose of impurities like metal particles and support material from the as-produced carbon nanotubes. Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) was used to characterize the CNTs both after and before purification. After acid treatment and centrifugation, the amount of amorphous carbon and iron particles significantly decreased. Additionally, following the purification process, the ID/IG decreased by 0.14 and the I2D/ID increased by 0.55 for the purified CNTs. Furthermore, the FTIR spectra of the untreated and functionalized CNTs confirm the presence of carboxyl groups on pure CNTs and -OH moieties in sorbed water.

Additive‐Free Transfer Hydrogenative Direct Asymmetric Reductive Amination Using a Chiral Pyridine‐Derived Half‐Sandwich Catalyst

AbstractChiral amines are broadly used compounds in pharmaceutical industry and organic synthesis, and reductive amination reactions have been the most appreciated methods for their syntheses. However, one‐step transfer hydrogenative direct asymmetric reductive amination (THDARA) that could expand the scope, simplify the operation and eliminate the use of additives has been challenging. In this work, based on the Xiao's racemic transfer hydrogenative reductive amination in 2010 and our recent work in novel chiral pyridine ligands, chiral half‐sandwich iridium catalysts were rationally designed and synthesized. Using the optimized catalyst and azeotropic mixture of formic acid and triethylamine as the hydrogen source, a broad range of α‐chiral (hetero)aryl amines, including various polar functional groups and heterocycles, were prepared in generally high yield and enantioselectivity under mild and operationally simple conditions. Density functional theory (DFT) calculation of the catalytically active Ir−H species and the key hydride transfer step supported the chiral pyridine‐induced stereospecific generation of the iridium center, and the enantioselection by taming the highly flexible key transition structure with multiple attractive non‐covalent interactions. This work introduced a type of effective chiral catalysts for simplified approach to medicinally important chiral amines, as well as a rare example of robust enantioselective transition‐metal catalysis.

Additive-Free Transfer Hydrogenative Direct Asymmetric Reductive Amination Using a Chiral Pyridine-Derived Half-Sandwich Catalyst.

Chiral amines are broadly used compounds in pharmaceutical industry and organic synthesis, and reductive amination reactions have been the most appreciated methods for their syntheses. However, one-step transfer hydrogenative direct asymmetric reductive amination (THDARA) that could expand the scope, simplify the operation and eliminate the use of additives has been challenging. In this work, based on the Xiao's racemic transfer hydrogenative reductive amination in 2010 and our recent work in novel chiral pyridine ligands, chiral half-sandwich iridium catalysts were rationally designed and synthesized. Using the optimized catalyst and azeotropic mixture of formic acid and triethylamine as the hydrogen source, a broad range of α-chiral (hetero)aryl amines, including various polar functional groups and heterocycles, were prepared in generally high yield and enantioselectivity under mild and operationally simple conditions. Density functional theory (DFT) calculation of the catalytically active Ir-H species and the key hydride transfer step supported the chiral pyridine-induced stereospecific generation of the iridium center, and the enantioselection by taming the highly flexible key transition structure with multiple attractive non-covalent interactions. This work introduced a type of effective chiral catalysts for simplified approach to medicinally important chiral amines, as well as a rare example of robust enantioselective transition-metal catalysis.

Photothermally Active Core-Shell Catalyst Based on UiO-66 and Polydopamine for Highly Effective Detoxification of Nerve Agents.

A new, photothermally active, catalytic composite (Fe3O4@PD@UiO-66) based on UiO-66 and polydopamine (PD) was prepared for the decomposition of chemical warfare agents (CWAs). An iron oxide nanoparticle was introduced to enable rapid recovery after the reaction. The PD layer enabled conversion of the absorbed light into heat under infrared (IR) irradiation and increased the reaction temperature, thereby increasing the reaction rate. Dendrimer-functionalized silica particles (NH2-DS) were used as heterogeneous catalyst regenerators instead of N-ethylmorpholine. Under IR irradiation, a mixture of Fe3O4@PD@UiO-66 and NH2-DS was effective as a heterogeneous catalyst for degrading DMNP, with a 5 min half-life in water. Without IR irradiation, the half-life of DMNP was 45 min using the same catalyst mixture. Various bases including arginine, histidine, and D4 were directly modified on the surface of Fe3O4@PD@UiO-66 and used without NH2-DS or N-ethylmorpholine in order to compare their reactivities. Furthermore, a mixture of Fe3O4@PD@UiO-66 and NH2-DS was used for the decomposition of nerve agents, including sarin (GB), soman (GD), and VX, under IR-LED irradiation. Remarkably, GB was effectively decomposed with a half-life of 4.2 min, and GD demonstrated a half-life of 8.7 min. VX was hydrolyzed with a half-life of 14.0 min.

ENSEMBLE METHODS FOR SOLVING PROBLEMS OF MEDICAL DIAGNOSIS

The authors proposed the consolidating method for analyzing series of observations based on a fitted model of a mixture of catalysts of the main components, which makes it possible to study any number of markers. Contrasting the longitudinal approach, it eliminates the need to connect regression analysis methods with their own uncertainties when choosing particular models. The consolidating method allows obtaining an original result in the subject area of early diagnosis of a disease: all options for using markers demonstrate an increase in classification accuracy with an increase in the length of a series of examinations.