TG-DTG Curves Research Articles

Effect of Potassium on the Co-Combustion Process of Coal Slime and Corn Stover

In this study, the combined combustion characteristics and gaseous product emissions of coal slime and corn stover were compared at different blending ratios. The TG-DTG curves indicate that the optimal performance is achieved when the corn straw blending ratio is 20%. Furthermore, the TG-FTIR coupling results demonstrated an increase in gas species as the blending ratio increased. The composition analysis of ash samples formed at various combustion temperatures using XRD and XRF indicated that a portion of KCl in the fuel was released as volatile matter, while another part reacted with Al2O3 and SiO2 components in the slime to form silica–aluminate compounds and other substances. Notably, interactions between the components of slime and potassium elements in corn stover primarily occurred within the temperature range of 800–1000 °C. These findings contribute to a comprehensive understanding of biomass and coal co-firing combustion chemistry, offering potential applications for enhancing energy efficiency and reducing emissions in industrial processes.

The efficient oxidation of waste resins via ternary alkali carbonate: Mechanisms of the Fe3+/Co2+-catalysis for enhanced fixing organic sulfur, iron and cobalt

The development of a highly efficient and cost-effective strategy for the fixation of organic sulfur, as well as radioactive metal nuclides holds great significance in the treatment of organic contaminants. Herein, ternary molten carbonate (Li2CO3-Na2CO3-K2CO3) was used for treating simulated waste resins containing Fe3+ and Co2+ (Fe-Co-CERs). The FT-IR and XPS analysis showed that the significant conversion process of organic sulfur in molten Li2CO3-Na2CO3-K2CO3 was sulfonic acid group (−SO3-) → sulfuryl group (−SO2-) → sulfur bond (−S-). The TG-DTG curves and the activation energy (E) revealed Fe3+ and Co2+ possess self-catalysis during the oxidation of Fe-Co-CERs, wherein distinctly facilitated the decomposition of −SO3- and −S- structures. The produced SO2 was further absorbed by molten carbonate to generate sulfate, which was confirmed by the observed increase in SO42- and the corresponding decrease of CO32–. The conversion of LiNaSO4 to K3Na(SO4)2 revealed that Li2CO3 is to function as a sulfur catcher at temperatures below 400 °C, which then as a crucial heat transfer medium at temperatures above 400 °C. The predominant forms of Fe and Co at 700 °C were primarily Co8FeS8, FeS, and CoS, which underwent oxidation to form CoFe2O4 and CoSO4 at 800 °C. The retention rate of S, Fe and Co reached 94.36 %, 97.48 % and 98.35 %, respectively. This molten salt oxidation (MSO) strategy exhibits promising potential for the treatment of organic contaminants containing sulfur and multiple metal elements.

Insight into co-pyrolysis of waste polypropylene and engine oil for liquid hydrocarbons and interaction mechanism by kinetic analysis and DFT simulation

Plastic pyrolysis is an efficient and cost-effective way of processing plastic waste, producing oil, gas, and coke. Oil production from waste plastics is a promising technology, and co-pyrolysis of multicomponent materials can help to promote reactions and optimize the products. Therefore, this study examines the co-pyrolysis reaction of another hazardous waste, engine oil, with waste plastics. The co-pyrolysis performance of plastic is first evaluated and the TG-DTG curve is dynamically analyzed. Then the synergistic behavior of polypropylene and engine oil co-pyrolysis is revealed through a combination of experiments, kinetic analysis, and DFT calculations. For physical interactions, waste engine oil can improve heat and mass transfer performance during pyrolysis, significantly increase the heating rate of the reactants. Furthermore, the yield of liquid-phase products is increased. For chemical interactions, the optimal pyrolysis path was studied according to activation energies and the interaction mechanism was elucidated. Moreover, the optimal pyrolysis paths of the engine oil and PP were identical, with the resulting pyrolysis products having minimal difference in carbon chains. However, the detailed reaction paths need to be further explored owing to the complexity of the process. And the detailed composition of the pyrolysis products requires further comprehensive analysis.

Preparation of xylooligosaccharides from rice husks and their structural characterization, antioxidant activity, and probiotic properties

Rice husks are rich in xylan, which can be hydrolyzed by xylanase to form xylooligosaccharides (XOS). XOS are a functional oligosaccharide such as improving gut microbiota and antioxidant properties. In this study, the structure and functional characteristics of XOS were studied. The optimal xylanase hydrolysis conditions through response surface methodology (RSM) were: xylanase dosage of 3000 U/g, hydrolysis time of 3 h, hydrolysis temperature of 50 °C. Under this condition, the yield of XOS was 150.9 mg/g. The TG-DTG curve showed that XOS began to decompose at around 200 °C. When the concentration of XOS reached 1.0 g/L, the clearance rate of DPPH reached 65.76 %, and the scavenging rate of OH reached 62.10 %, while the clearance rate of ABTS free radicals reached 97.70 %, which was equivalent to the clearance rate of VC. XOS had a proliferative effect on four probiotics: Lactobacillus plantarum, Lactobacillus brucelli, Lactobacillus acidophilus, and Lactobacillus rhamnosus. However, the further experiments are needed to explore the improvement effect of XOS on human gut microbiota, laying a foundation for the effective utilization of XOS. XOS have a wide range of sources, low price, and broad development prospects. The reasonable utilization of XOS can bring greater economic benefits.

Magnetic, dielectric and thermal study of CoNiFe2O4 nanoparticles

CoxNi1-xFe2O4 (x = 0.2–0.8) (CNFO) nanoparticles have been prepared using a low temperature hydrothermal technique. X-ray diffraction confirmed the cubic spinel structure of the nanoparticles, offering an increasing trend of lattice parameters from 8330 to 0.8345 nm as a function of Co-content. The microstructures were analysed using FESEM and TEM. The average grain size determined using FESEM images for x = 0.2–0.8 was found in the range from 110 to 183.7 nm. The TEM images show asymmetrical sphere-like particles, with the particle size changing from 69.4 to 82.1 nm as a function of ‘x’. The hysteresis curves were recorded for x = 0.2–0.8 to understand the ferrimagnetic behavior. The saturation magnetization (Ms) varies unsystematically between 35.3 and 43.3 emu/g with ‘x’, while a high magnetic moment of 1.819 μB/f.u. is found at a high Co-content. The paramagnetic term (χ x 10−5) goes on increasing from 125 to 148 emu/g.Oe with ‘x’. The zero-field cooled (ZFC) and field cooled (FC) curves provide the decreasing trend of variation blocking temperature (TB) from 270 to 260 for x = 0.2–0.6, whilst for x = 0.8, it is increased to 280 K. The high real part of the permittivity of ∼ 12.42 and low imaginary part of the permittivity of ∼0.638 are recorded at 8 MHz for x = 0.2, indicting energy storage applications. The power law fit was applied to log σac-log ω plots and the dc-electrical conductivity was evaluated. The TG-DTG and DSC curves revealed mass loss and transition temperatures for x = 0.2–0.8 as a function of temperature.

Thermal, Morphological, and mineralogical characterization of ancient potsherds: Insights from activation energy and degradation profiles

The six representative potsherds sourced from the excavated Buddhist site of Udayagiri, Odisha, in eastern India, were studied using analytical characterization techniques of X-ray diffractometry (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), thermogravimetry (TG-DTG), and a porosity study. The analysis has unveiled the clay composition, firing temperatures, and environment along with internal morphology of these potsherds after firing process. The thermal behavior of the pottery samples was meticulously examined and degradation profiles depicted through TG-DTG curve. The activation energy of potsherds was calculated using the Horowitz and Metzger equation, shedding light on the various stages of degradation. Notably, the calculated activation energies for the first stage of degradation ranged from 5.78 to 16.64 kJ/Mole, while for the 2nd/3rd stage degradation, the range was between 2.59 KJ/Mole to 8.38 KJ/Mole, underlining the intricate firing processes involved. This research has successfully estimated firing temperatures across different environmental conditions, spanning from 450 to 900 °C. The pottery fragments were categorized into two distinct varieties following a comprehensive analysis of firing temperature, inclusions, morphological characteristics, firing conditions, and degradation profiles. The multifaceted approach employed in this study has contributed significantly to our understanding of these potsherds' composition and their firing profile.

Thermal pyrolysis of two synthesized Amadori derivatives prepared by protecting the active groups

Maillard intermediates, especially Amadori compounds, played a crucial role in the formation of flavor or adverse Maillard products, directly influencing the sensorial and organoleptic properties of foodstuff. Here, in order to modulate the degradation products of Amadori compounds, the active hydroxyl and carboxyl groups on the Amadori skeleton were protected, then two new Amadori derivatives based on leucine (Leu-AD) and glutamic acid (Glu-AD) were obtained with relatively high yield. The subsequent TG-DTG and DSC tests showed that both Leu-AD and Glu-AD were stable at room temperature and could be fully degraded at 400 °C. The TG-DTG curve of Glu-AD was more complicated than that of Leu-AD due to the asynchronous degradation of the two carboxyl groups on Glu-AD. Their pyrolytic products also exhibited great difference, specifically, the flavor products released from Leu-AD were mainly pyrroles and Strecker degradation products, while the pyrolytic products of Glu-AD mainly included methyl substituted furans derived from the pyranose ring and esters resulting from the degradation of glutamic acid moiety. Comparatively, the species and relative content of their (Leu-AD and Glu-AD) pyrolytic products were distinct to the reported flavor products generated from the corresponding Amadori compounds and glucose-leucine/glutamic acid mixtures, indicating Amadori derivatives could be an alternative flavor precursors generating Maillard-type aroma.

Research on the Combustion Performance of Municipal Solid Waste in Different Sorting Scenarios: Thermokinetics Investigation via TG-DSC-FTIR-MS.

Waste sorting is regarded as one of the most important strategies for municipal solid waste (MSW) management. The changes in the combustion parameters after MSW sorting had a significant impact on the actual operation of the boiler. In the present study, the effects of heating rate on combustion characteristics and dynamics of MSW in different sorting scenarios were studied using the thermogravimetry (TG)-differential scanning calorimetry (DSC)-Fourier transform infrared (FTIR)-mass spectrometry (MS) technique. TG-DSC analysis showed that the heat released from MSW combustion at different heating rates ranged from 1394.1 to 4130.1 J/g. According to the TG-DTG curves, the combustibility of 30% sorted MSW was increased by 1.2 times compared to that of the unsorted scenario. In the 30% sorted scenario, the average activation energies were estimated to be 161.24 and 159.93 kJ/mol based on the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods, respectively. Based on the Coats-Redfern (CR) method, the minimum activation energies for unsorted and 20% sorted scenarios were 148.74 and 135.53 kJ/mol at 523 to 606 K, respectively, while they were 29.42 and 33.22 kJ/mol at 606 to 780 K. XRF analysis showed that the alkali and alkaline earth metal oxides in the ash contributed to a high risk of slagging and scaling. This work can provide a scientific basis for the real situation of MSW incineration.

Co-pyrolysis of discarded bakelite with polystyrene to fuel: Thermokinetic, thermodynamic, synergetic analysis and batch pyrolysis studies

The discarded bakelite cannot be easily recycled into useful products as it gets charred upon heating. The addition of thermoplastics like polystyrene (PS) to bakelite during pyrolysis may improve the decomposition of the bakelite. The design of a co-pyrolysis process needs kinetic and thermodynamic analysis. So, this work investigates the co-pyrolysis kinetics, and synergy of PS-blended bakelite (BL) (1:1 by weight) by using model-fitting and model-free methods. This is followed by thermodynamic analysis and batch pyrolysis studies to understand the feasibility of the process. To achieve it, the thermal degradation experiments are conducted at 5, 10, 20, 30, and 50 °C/min heating rates in a nitrogen environment, from 30 to 1000 °C. The TG-DTG curve of the blended sample includes two major weight loss steps (215-375 °C and 375-490 °C). The blending of PS with bakelite causes a shift in the pyrolytic degradation temperature zone and the appearance of a synergetic effect. Significant variation in the kinetics, thermodynamics, and mechanism of thermal degradation is observed due to the blending of polystyrene. The pyrolytic oils obtained in batch pyrolysis at 450 °C contain 58.27 wt% aromatic hydrocarbons (C7-30) and 40.93 wt% saturated hydrocarbons (C12-29) as major ingredients, as per the GC–MS analysis.

THE CATALYTIC EFFECT OF ZINC-OXIDE (ZNO) ON THE KINETICS OF COMBUSTION REACTIONS OF SOLID WASTE MATERIALS

This study aims to determine the catalytic effect of ZnO on the kinetics of the decomposition reaction of burning solid waste. ZnO catalyst was chosen because it has high mobility and reactivity. samples were prepared and randomly selected consisting of 12 types of inorganic waste and 10 types of organic waste. The research instrument uses (DTA) Differential Thermal Analysis proximate testing. From this test the data in the form of a mass decrease graph will be analyzed descriptively. The description of the data is displayed through the TG-DTG curve and the calculation of the activation energy (Ea) using the fitting model. the DTG curve identifies three peaks indicating the decomposition stages of the three components have different characteristics. The decomposed components are 1. lignocellulosic organic and low stability organic components, 2. Volatile substances from plastic components, 3. hydrocarbon residues and ash reformation. The combustion temperature increases in samples with high catalyst concentrations, but the burnout temperature decreases in samples with high catalyst concentrations. The DTA curve shows the increased reactivity of samples with high catalyst concentrations. Oxidative reactions which are exothermic/external heating increase in samples with high catalyst concentrations. The catalytic effect on the addition of zinc-oxide (ZnO) catalyst concentration to the components showed a decrease in the hydrocarbon component and an increase in the short chain hydrocarbon component. Increasing the concentration of zinc-oxide (ZnO) catalyst in the sample increases the activation energy. However, overall the addition of catalyst concentration in the combustion of organic-inorganic solid waste samples was able to reduce the activation energy at the end of the combustion reaction

Selecting the Technology of Sodium Silicate Modified Poplar with the Highest Performance by Fuzzy Orthogonal Method

Sodium silicate modification can improve the overall performance of wood. The modification process has a great influence on the properties of modified wood. In this study, a new method was introduced to analyze the wood modification process, and the properties of modified wood were studied. Poplar wood was modified with sodium silicate by vacuum-pressure impregnation. After screening using single-factor experiments, an orthogonal experiment was carried out with solution concentration, impregnation time, impregnation pressure, and the cycle times as experimental factors. The modified poplar with the best properties was selected by fuzzy mathematics and characterized by SEM, FT-IR, XRD and TG. The results showed that some lignin and hemicellulose were removed from the wood due to the alkaline action of sodium silicate, and the orderly crystal area of poplar became disorderly, resulting in the reduction of crystallinity of the modified poplar wood. FT-IR analysis showed that sodium silicate was hydrolyzed to form polysilicic acid in wood, and structural analysis revealed the formation of Si-O-Si and Si-O-C, indicating that sodium silicate reacted with fibers on the wood cell wall. TG-DTG curves showed that the final residual mass of modified poplar wood increased from 25% to 67%, and the temperature of the maximum loss rate decreased from 343°C to 276°C. The heat release and smoke release of modified poplar wood decreased obviously. This kind of material with high strength and fire resistance can be used in the outdoor building and indoor furniture.

Decomposition behavior and kinetics of Beydili and Ihsangazi oil shale deposits (Turkiye) by TG-DTG-MS

This research mainly investigates the decomposition behavior and kinetics of Beydili and Ihsangazi oil shale deposits (Türkiye) by TG-DTG and MS techniques. In the initial stage of the research, geochemical and organic characterization (total organic carbon, rock-eval, fisher assay, x-ray fluorescence, etc.) of the oil shale samples were determined. TG-DTG-MS analyses of the oil shale samples were performed at three different heating rates in an air atmosphere. In all the oil shale samples studied, the TG-DTG curves indicated that the decomposition of oil shale samples followed two successive reaction stages in different temperature intervals, known as pyrolysis and mineral decomposition. In these two stages, reaction intervals, peak temperature, mass loss, derivative mass loss rate values, and gaseous constituent (MS analysis) of oil shale samples are all determined. At the same time, the different combustibility indices, such as the ignition index, combustion index, and reactivity of oil shale samples, are also determined. Also, for each reaction region, activation energy values were calculated using two different model-free methods known as Kissinger - Akahira – Sunose (KAS) and Ozawa - Flynn – Wall (OFW). In pyrolysis and mineral decomposition regions, the activation energy values varied between 73.9 and 186.4 kJ/mol and 103.3–297.1 kJ/mol.

Thermal degradation and kinetic studies of redwood (Pinus sylvestris L.)

AbstractIn this scientific paper, thermochemical conversion of redwood (RW) was studied. Using the thermogravimetric analysis' technique (TGA), the thermal behavior of RW samples was examined at four heating rates ranging from 5 to 20 K min−1 in inert atmosphere between 300 and 900 K. Two main objectives have been set for this study; the first one was the determination of the kinetic decomposition parameters of RW (Pinus sylvestris L.), and the second one was the study of the variation of characteristic parameters from the TG-DTG curves of the main RW's components, such as; cellulose, hemicellulose and lignin. The kinetic analysis was performed using three isoconversional methods (Vyazovkin (VYA), Friedman (FR) and Flynn-Wall-Ozawa (FWO)), Avrami theory method and the Integral master-plots (Z(x)/Z(0.5)) method to estimate activation energy (Ea), reaction order (n), pre-exponential factor (A) and model kinetic (f(x)) for the thermal decomposition of cellulose, hemicellulose and lignin components.The DTG and TG curves showed that three stages identify the thermal decomposition of RW, the first stage corresponds to the decomposition of hemicellulose and the second stage corresponds to the cellulose, while the third stage corresponds to the lignin's decomposition. For the range of conversion degree (x) investigated (0.1 ≤ x ≤ 0.7), the mean values of apparent activation energies for RW biomass were 127.60–130.65 KJ mol−1, 173.74–176.48 KJ mol−1 and 197.21–200.36 KJ mol−1 for hemicellulose, cellulose and lignin, respectively. Through varied temperatures from 550 to 600 K for hemicellulose, from 600 to 650 K for cellulose and from 750 to 800 K for lignin, the corresponding mean values of reaction order (n) were 0.200 for hemicellulose, 0.209 for cellulose and 0.047 for lignin. The pre-exponential factor's average values for three components of RW ranges from 0.08 × 1012 s−1 to 2.5 × 1012 s−1 (Ahemicellulose = 1.09 × 1012 s−1), 0.10 × 1014 s−1 to 0.28 × 1014 s−1 (Acellulose = 0.17 × 1014 s−1) and 3.07 × 1016 s−1 to 3.69 × 1016 s−1 (Alignin = 3.33 × 1016 s−1), respectively. The experimental data of RW had overlapped the D4, D2 and F3 in the conversion degree of 10–30%, 30–55% and 55–70% for the three components, respectively.

Experimental research on the volatilization and condensation of ammonium bisulfate as SCR byproduct

Abstract In this paper, the research progress of ammonium bisulfate (ABS) volatilization in coal-fired power plants the SCR denitrification process was reviewed. Combination with self-made experiments, SEM, flue gas analyzer and TG-DTG curves of ABS and ion chromatography. The volatilization and condensation characteristics of ABS were investigated carefully. Results show that as the temperature increased by 50 oC, the ABS/AS volatilization rate increased by an order of magnitude. The decomposition process of ABS should have a two-step reaction. The reaction in the initial volatiliza-tion stage is ABS dehydration turned into (NH4)2S2O7. The reaction in the rapid volat-ilization stage is (NH4)2S2O7 decomposed into NH3, N2, SO2 and H2O. There is an inter-section in the reaction temperature range (especially 300 oC) between the two-step re-action. This research provides an experimental basis for temperature control of ABS to avoid air pre-heater fouling.

Isoconversional kinetic analysis of the pyrolysis of Salt Lake industrial waste bischofite with isothermal reaction time predictions

Extracting magnesium resources from Salt Lakes industrial waste bischofite by pyrolysis technology has become a feasible waste utilization method. High-temperature corrosion has become a safety issue during bischofite pyrolysis. Thus, pyrolysis behavior and kinetic analysis are essential to control pyrolysis reactions. In this study, a thermogravimetric analyzer was used to understand the pyrolysis behavior of bischofite. TG-DTG curves show that the bischofite pyrolysis includes dehydration and coexistence stages. Thermal hazards caused by corrosive gases appear in the temperature range of 174.8–202.3 °C. The kinetic parameters were calculated using three model-free methods (FWO, KAS, and FR) and a master plots method. The results show that the activation energy of the dehydration stage is smaller than the coexistence stage. The reliability of the master plots method was also investigated. The results show that the reaction models for the dehydration (II-1, II-2, and II-3) and coexistence stages (IV-3) were credible. In addition, the isothermal method was used to predict the reaction time under different temperature programs. The results show that controlling the reaction temperature at 700–800 ℃ can improve the conversion efficiency and product quality. This work provides basic data for promoting the development of bischofite pyrolysis technology.

Thermodynamic variation law and influence mechanism of low-temperature oxidation of lignite samples with different moisture contents

Coal spontaneous combustion (CSC) is one of the main disasters that threaten the safe production in coal mines. Moisture, which is the main factor affecting coal oxidation, has a considerable impact on CSC. In this paper, the variation characteristics of TG-DTG and DSC-DDSC curves of two kinds of lignite during low-temperature oxidation were investigated. The following results were obtained: Oxidation-induced heat production (OHP) starts to play a leading role in the temperature range of 50–75 °C; pyrolysis-induced heat absorption (PHA) grows faster than OHP in the temperature range of 70–130 °C; and OHP is dominant in the temperature range of 130–260 °C. Furthermore, for coal samples from Shengli (SL) Coal Mine and Yuanbaoshan (YB) Coal Mine, the initial heat release temperature and the end temperature both conform to the Lorentz function T=T0+2A(B4(M−Mc)2+B2). Thermodynamic parameters reach the maximum under the moisture content of 12%–17% where the CSC is the most likely to occur. In the oxygen adsorption and weight gain stage, the activation energy decreases and gradually stabilizes with the increase in moisture content. In the accelerated oxidation stage, moisture in coal plays a chemical catalytic role in the processes of oxygen chemical adsorption and intermediate complex formation and decomposition. However, excessive moisture cannot accelerate the coal-oxygen composite reaction.

Study on coupled combustion behaviors and kinetics of plastic pyrolysis by-product for oil

The pyrolysis of waste plastics alleviates the ecological pollution of plastics. In addition to the high-quality oil component of the target product, there are solid residues from incomplete pyrolysis. These residues have a great potential as fuels due to their high carbon content and partial oil content. Currently, few studies have focused on the rational utilisation of waste plastics pyrolysis by-products, especially the simultaneous combustion of carbon and oil and their coupled combustion mechanisms. In this paper, the combustion performance of plastic pyrolysis residues with different particle sizes was firstly evaluated and the TG-DTG curves were kinetically analysed. The melting characteristics of the ashes were observed by XRD and SEM. It was found that the samples showed better combustion performance as the particle size increased. However, the particle size had less effect on the combustion of the residue after plastic pyrolysis, with multiple peaks of weight loss during the combustion process. Oil-carbon coupling characteristic promotes combustion reaction. In addition, the activation energy of combustion of the residue after plastic pyrolysis is low according to the kinetic parameters. Therefore, plastic pyrolysis residue has the advantage of low combustion point compared to coal and is an ideal fuel.

Influence and action mechanism of pressure on pyrolysis process of a low rank Naomaohu coal at different temperatures

In this study, the effect of pressure on the pyrolysis characteristics of Naomaohu coal and the physicochemical properties of char during slow pyrolysis is evaluated, and the mechanism of pressure is explored. The results show that the influences of pressure on char yield and physical properties are reflected in both promoting and inhibiting effect, and the latter is more obvious with the increasing temperature. As the pressure increases, the char yield first reduces and then improves, and at 600 °C and 800 °C the minimum yields are in 1.0 MPa and 0.1 MPa, which are 57.48% and 54.04%, respectively. The SBET of char increases first and then decreases. At 800 °C, the SBET of char increases from 7.86 m2/g at 0.1 MPa to 19.81 m2/g at 0.5 MPa and then decreases. The effect of pressure on the chemical properties of char is relatively simple. As the pressure rises, the content of functional groups in char reduces and the degree of graphitization enhances. The TG-DTG curve, XPS, BET, SEM test, experiments on the pressurized micro-fluidized bed reaction analyzer and pressurized pyrolysis-gas chromatography/mass spectrometry show that the pressure mainly affects the pyrolysis process by affecting the secondary reaction of the primary volatiles in the particle and is related to temperature.

Photoluminescent performance of bright orange light emanating Sm(III) complexes with β-ketoester functionalized ligand for competent photophysical appliances

To contribute in the progression of optical materials, a series of five novel samarium (III) complexes are synthesized using bidentate ligand 2-(methacryloxy)ethylacetoacetate (MAE), and neutral heterocyclic ancillary ligands (batho, bipy, phen, and dmbipy). The structural and spectral aspects are analysed by the use of numerous techniques viz. elemental analysis (EDX & CHN), UV– visible absorption, IR, NMR, etc. Thermal stability is measured via TG-DTG curves. Diffused reflectance spectra is employed for the calculation of optical energy gap of ligand and synthesized complexes which is observed in the range of WBGs (Wide bandgap semiconductors). The HOMO-LUMO energy gap calculated theoretically and their results are resembled with experimental results. The emission profile of synthesized complexes depicts well resolved and intense peaks at 565, 600, and 649 nm ascribed to 4G5/2→ 6HJ (J = 5/2, 7/2, 9/2) transitions by browsing at 353 nm under UV- excitation. One of them (600 nm) is dominant and illustrates magnetic and electric dipole transitions which is responsible for bright orange emission. The results of chromaticity i.e., color coordinates, CCT, and CP are also agreed with the emission of bright orange light. Interesting results of synthesized complexes promote their usage in multipurpose photophysical materials.

Interactive effects of NOx synergistic and hydrothermal aging on soot catalytic combustion in Ce-based catalysts

The Thermal gravimetric analysis (TGA) with In-situ Fourier transform infrared Spectrometer (In-FTIR) of fresh/hydrothermal aging Ce-based catalysts was carried out for the soot oxidation at different transition metal Mn, alkali metals K, precious metals Ag and rare earth metal Zr doping which used to extend the hydrothermal aging resistance of CeO2 catalysts. The comprehensive combustion index S, combustion stability index Rw and peak temperature Tp from TG-DTG curves were extracted to evaluate the soot catalytic combustion performance, and the NO2/NO ratio during the combustion process was also measured to analyze the NOx synergistic oxidation performance. The effect of metal oxide doping type, doping ratio and hydrothermal aging time on S, Rw, Tp and NO2/NO ratio was evaluated to reveal the change in soot catalytic combustion performance. The result shows that, compared with PU, the NOx synergistic oxidation performance of various metal oxides modified Ce-based catalysts ranked as K > Ag > Mn > Zr. With the metal oxide doping ratio increased, the soot catalytic combustion performance of K and Zr metal oxides modified Ce-based catalysts decreased, Mn and Ag metal oxides modified catalyst increased. After hydrothermal aging treatment, the NOx synergistic oxidation performance of various metal oxides modified Ce-based catalysts ranked as K > Ag > Mn > Zr. This work is helpful to reveal the basic mechanism of hydrothermal aging metal oxide modified Ce-based catalyst and NOx during soot catalytic combustion process.