Stable Ether Research Articles

Ether and ester formation from peroxy radical recombination: a qualitative reaction channel analysis

Abstract. The least volatile organic compounds participating in atmospheric new-particle formation are very likely accretion products from self- and cross-reactions of peroxy radicals (RO2). It has long been assumed that the only possible accretion product channel in this reaction is that forming a peroxide (RO2+RO2→ROOR+O2), but it has recently been discovered that a rapid alkoxy radical (RO) decomposition may precede the accretion step of the mechanism, forming slightly fragmented but more stable ether (ROR) or ester (RC′(O)OR) accretion products. In this work, the atmospheric implications of this new reaction channel have been explored further by using a modified version of the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) software to generate a large amount of representative RO2 + RO2 reactive pairs formed from the oxidation of typical primary hydrocarbons and by applying structure–activity relationships (SARs) to predict the potential accretion products. These data are analysed in terms of the formation of low-volatility products, and new discoveries are presented on what types of RO2 are especially efficient (and which are surprisingly inefficient) at forming accretion products. These findings are discussed in terms of the atmospheric relevance of these new RO2 + RO2 reaction channels. As the generation of these data rests on several simplifications and assumptions, many open questions worthy of later studies are also raised.

Inhibitory Kinetics and Mechanism of the Low Temperature Oxidation of Coal by Polyethylene Glycol-Citric Acid

ABSTRACT To address the issues of low inhibition rate, high cost, and insufficient research on physicochemical synergistic inhibition mechanisms, this study examined the inhibitory effect and mechanism of Polyethylene Glycol-Citric Acid (PEG-CA) on low-temperature oxidation of coal. Differential scanning calorimetry (DSC) was used to analyze the inhibition and thermal behavior at various inhibitor ratios. Fourier transform infrared spectroscopy was used to experimentally assess changes in the functional groups of the coal samples pre- and post-inhibition. Principal component analysis identified the key mechanism of PEG-CA in inhibiting the low-temperature oxidation of coal. It showed that PEG-CA increased the heat absorption of the coal and delayed the average thermal equilibrium temperature of the coal oxidation process by more than 70°C. The addition of PEG-CA increased the maximum heat absorption rate of the coal sample by 2.4 times and the activation energy of coal oxidation by 1.6–3.9 times. The primary inhibition mechanism is that PEG-CA-forming chelates with the metal ions of coal, preventing C-H bond activation and reducing the content of this functional group. Additionally, PEG-CA etherifies with the hydroxyl groups of the coal, creating relatively stable ether bonds. This study offers a cost-effective and eco-friendly solution for the coal mining industry and provides a new theoretical foundation for developing composite corrosion inhibitors and controlling spontaneous coal combustion.

Revealing patterns in reducing the fire-hazardous properties of insulation made from plant raw materials

An issue related to the use of hemp bundle insulation for building structures is to ensure their fire resistance under the action of a low-calorie ignition source. Therefore, the object of research was the change in the properties of the insulation during fire protection with its compositions capable of forming a layer of pinocoke under the influence of high temperature. On the basis of experimental data, it was established that at fire protection of insulation with a fire retardant agent, hydrolytic stable ethers containing phosphorus and nitrogen atoms are formed on the surface of the fibers. According to the temperature values and the shape of peaks on the DTA curve, it was established that at fire protection, the height of the peaks decreases and the width increases, which characterize the flow of exothermic transformations and the destruction of hemp fibers. At the same time, it was established that the formed residue has 13.3 % for impregnation and 26.6 % for coating. It has been proven that in the process of thermal action on the fire-resistant coating, the heat insulation process of the insulation consists in the formation of soot-like products on the surface of the material. So, it was determined that the sample did not catch fire, it was charred in the place of the radiation panel, and the burning was not recorded. On the other hand, for a sample of insulation treated with a coating during thermal action, the formation of a heat-insulating layer of foam coke occurred, which inhibits the penetration of heat, the temperature of flue gases did not exceed 100 °C, and the flammability index was 0. The practical significance is that the results were taken into account when designing buildings and structures. So, there are reasons to assert the possibility of targeted regulation of fire protection processes of insulation by applying coatings that form a protective layer on the surface of the material

Study on the Properties of Proanthocyanidins Modified Temperature Sensitive Gel Composite Inhibitor for Inhibiting Coal Spontaneous Combustion

ABSTRACT To address the disadvantages of the single inhibition effect, poor inhibition effect and short inhibition life of the inhibitors used in coal mining, a temperature-sensitive gel composite inhibitor was developed in this study. Polyacrylic acid (PAA), n-isopropylacrylamide (NIPA) and proanthocyanidin (OPC) were used as raw materials. The inhibition property and mechanism of the temperature-sensitive gel composite inhibitor were studied using scanning electron microscopy (SEM), infrared spectroscopy (IR), temperature sensitivity tests and thermogravimetric analysis (TGA). The results indicate that OPC/P(NIPA-co-AA) is able to fill the coal interstitial space and isolates oxygen to weaken the oxygen-coal reaction. The absorption peak of the chemically stable ether bond increases, and the content of methyl and methylene groups that can easily react with oxygen decreases in the OPC/P(NIPA-co-AA)-inhibited coal sample, indicating that the stability of the inhibited coal sample is improved. The sensitive temperature of OPC/P(NIPA-co-AA) is around 55°C, and the composite inhibitor reduces the temperature of water loss when the coal heat storage reaches the sensitive temperature, which improves the physical inhibitory effect. The ignition temperature of the OPC/P(NIPA-co-AA)-inhibited coal sample is 6.94°C higher than that of the raw coal, whereas the oxidation reaction of the OPC/P(NIPA-co-AA)-inhibited coal sample is more difficult. The temperature-sensitive gel composite inhibitor exhibits good inhibitory performance in both physical and chemical aspects, and it can significantly inhibit the spontaneous combustion of coal.

The accumulation of Li2CO3 in a Li-O2 battery with dual mediators.

One of the most important challenges facing long cycle life Li-O2 batteries is solvent degradation. Even the most stable ethers, such as CH3O(CH2CH2O)CH3, degrade to form products including Li2CO3, which accumulates in the pores of the gas diffusion electrode on cycling leading to polarisation and capacity fading. In this work, we examine the build-up and distribution of Li2CO3 within the porous gas diffusion electrode during cycling and its link to the cell failure. We also demonstrate that the removal of Li2CO3 by a redox mediator can partially recover the cell performance and extend the cycle life of a Li-O2 battery.

Synthesis of porous carbon with low oxygen content from fulvic acid for high voltage organic supercapacitors

The operating voltage of over 3.0 V is a severe challenge for commercial supercapacitors in organic electrolyte, which raises rigorous requirements for the structure and composition characteristics of porous carbon. There are few reports regarding the construction of ultra-high voltage withstanding porous carbon derived from cheap biomass carbon sources. Herein, using cheap and renewable fulvic acid (FA) and graphene oxide (GO) as carbon precursors, the ultra-high withstanding voltage 2D porous carbon nanosheets are synthesized through KOH activation and annealing treatment, assisted by the π-π conjugation and hydrogen bonding. The incorporation of GO plays an important role in modulating the 2D nanosheet morphology of FA derived porous carbon, enhancing the e-conductivity and reducing the OFGs of porous carbons, which makes significant contribution to improving the structural stability and electrochemical performance of material. The obtained FG1% C/C composite simultaneously exhibits high specific surface area (2593 m2/g) and desirable e-conductivity (101 S m−1). More critically, it possesses highly stable surface chemical microenvironment with very-low surface oxygen content of 2.7 at.%, mainly existing as stable ether and quinone bonds. Thus, FG1% exerts ultra-high withstanding voltage up to 3.3 V in commercial TEABF4/PC electrolyte with the maximum energy density of 68.6 Wh kg−1, superior to most of the literatures, also it shows excellent stability throughout its lifespan, maintaining improved capacity retention rate (88.9%) at 2.5 A/g over 10,000 cycles. This work pares the way for the architecture design of high withstanding voltage porous carbon.

Study on the Synergistic Antioxidant Effect of Coal Inhibitors and the DFT Calculation

ABSTRACT In order to improve efficiency when preventing and controlling spontaneous combustion of coal, a type of compound inhibitor with tea polyphenol and vitamin E as the chemical inhibitor, grafted on a copolymer hydrogel, was prepared. The oxidation resistance of the compound inhibitor to coal was analyzed by thermogravimetric test, Fourier infrared spectroscopy, and quantum chemistry theory. The experiment results showed that: The optimum ratio of tea polyphenols and vitamin E was 1:0.05; tea polyphenols and vitamin E inhibited the oxidation of coal by capturing the decomposition products of hydroperoxides and finally forming stable ether structures, and slowing down the hydrogen supply reaction between aliphatic hydrocarbons and carboxyl groups; the antioxidant properties of vitamin E (VE) and tea polyphenols (EGCG) were mainly due to the presence of active hydroxyl groups in the ring; H22 of VE and H38 of EGCG were able to inhibit the chain reaction of coal effectively. This study provides a new technical method for development of comprehensive fire prevention technology to address spontaneous combustion of coal, and provides a reference for the research into the inhibition mechanism of spontaneous combustion of coal.

Research on chemical resistance characteristics of water-immersed coal with different metamorphic degrees

In order to reduce the risk of spontaneous combustion of coal left after long-term flooding in the goaf of the mine, in this paper, the inhibitory properties of different inhibitors on two kinds of water-immersed coals with different metamorphic degrees were studied in depth. The experiment selected Pingzhuang brown coal and Shaqu coking coal as research objects. The raw coal and water-immersed coal samples were compared and analyzed by thermogravimetric experiment method and Fourier transform infrared spectroscopy experiment method. The study showed that the activation temperature of brown coal and coking coal decreased by 7.91 and 2.25 °C respectively, and the activation energy decreased by 43.18 kJ/mol and 20.58 kJ/mol respectively. The natural tendency of coal was enhanced after water immersion, and water immersion had a greater impact on low-metamorphic brown coal. After adding four kinds of inhibitors, MgCl2, TEMPO, TPPI and PA to the two water-immersed coals, it was found that TPPI could significantly reduce the heat release rate of water-immersed brown coal, and the reduction value was 10.49 W/mg. The dry cracking temperature of water-immersed brown coal increased by 11.75 °C, and PA greatly increased the combustion activation energy of water-immersed coking coal by 25.77 kJ/mol. Meanwhile, it was found from the microscopic active groups that TTPI increased the content of water-immersed brown coal ether bonds by 4.84%. The absorption peak intensity of oxygen-containing functional groups such as C=O was significantly weakened. Similarly, PA also produced a large number of stable ethers in water-immersed coking coal, whose content increased by 5.21%, and the hydroxyl content decreased most significantly. The decomposition of TPPI into phosphoric acid after heating can inhibit the growth of active groups such as a large number of oxygen-containing functional groups in the water-immersed brown coal, thereby reducing the risk of spontaneous combustion. As a metal chelator, PA can reduce the catalytic effect of metal ions in water-immersed coking coal with fewer active groups, and inhibit coal spontaneous combustion by generating stable metal complexes to increase activation energy. This indicated that TTPI had the best inhibitory effect on water-immersed brown coal, while PA was more suitable for water-immersed coking coal.

Synthesis of Novel Arsonolipids and Development of Novel Arsonoliposome Types.

Arsonolipids represent a class of arsenic-containing compounds with interesting biological properties either as monomers or as nanostructure forming components, such as arsonoliposomes that possess selective anticancer activity as proven by in vitro and in vivo studies. In this work, we describe, for the first time, the synthesis of novel arsono-containing lipids where the alkyl groups are connected through stable ether bonds. It is expected that this class of arsonolipids, compared with the corresponding ester linked, will have higher chemical stability. To accomplish this task, a new methodology of general application was developed, where a small arsono compound, 2-hydroxyethylarsonic acid, when protected with thiophenol, can be used in an efficient and simple way as a building block for the synthesis of arsono-containing lipids as well as other arsono-containing biomolecules. Thus, besides the above-mentioned arsonolipid, an arsono cholesterol derivative was also obtained. Both ether arsonolipid and arsono cholesterol were able to form liposomes having similar physicochemical properties and integrity to conventional arsonoliposomes. Furthermore, a preliminary in vitro anticancer potential assessment of the novel ether arsonolipid containing liposomes against human prostate cancer (PC-3) and Lewis lung carcinoma (LLC) cells showed significant activity (dose- and time-dependent), which was similar to that of the conventional arsonoliposomes (studied before). Given the fact that novel arsonolipids may be more stable compared to the ones used in conventional arsonoliposomes, the current results justify further exploitation of the novel compounds by in vitro and in vivo studies.

A novel nano-modified inhibitor of tert-butyl hydroquinone/sodium polyacrylate for inhibiting coal spontaneous combustion

In this study, we developed a modified antioxidant-type inhibitor (MAT-inhibitor) to address the disadvantages of the inhibitors that are currently used in coal mines, namely single effect, poor thermal stability, and low versatility. Sodium acrylate, tert-butyl hydroquinone (TBHQ), and montmorillonite were used as raw materials. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) were adopted to analyze the inhibition performance and mechanism of the MAT-inhibitor. Research indicates that the MAT-inhibitor is able to fully cover the coal surface, and has strong water absorption qualities. TBHQ in the inhibitor significantly reduces the content of methyl (-CH3), methylene (–CH2–), hydroxyl (-OH), and carboxyl groups (-COOH) in the coal radical chain reaction. In the meantime, it increases the stable ether bond content (C–O–C). After treatment with the MAT-inhibitor, the dry cracking temperature of the coal sample increased by 52.8 °C, and the maximum thermal mass loss rate decreased by 0.84%/min. This proved that the inhibitor has superior thermal stability and high inhibition performance. Therefore, regardless of the physical, chemical, and thermal stability aspects, the MAT-inhibitor can be used to control the spontaneous combustion of coal.

Upcycling Polytetrahydrofuran to Polyester

Upcycling Polytetrahydrofuran to Polyester

A stable covalent organic framework cathode enables ultra-long cycle life for alkali and multivalent metal rechargeable batteries

Organic electrode materials are promising candidates for sustainable and large-scale energy storage. However, the short lifespan caused by low redox stability and high solubility in electrolytes severely hinders their application. Hexaazatrinaphthalene (HATN), a popular organic cathode material possessing high theoretical capacity, also confronts this problem. Herein, for the first time, we combine chemically stable ether bonds with HATN units to synthesize a HATN-based covalent-organic framework (COF), HATNHHTP, to improve the cathode's structural stability and suppress solubility. By incorporating HATNHHTP with CNTs, the product HATNHHTP@CNT achieves high capacity utilization (> 210 mA h g−1 at 50 mA g−1) due to sufficient exposure of active sites and enhanced electronic conductivity. The stable bonding and pseudocapacitive behavior endow HATNHHTP@CNT with the longest lifespan of 4100 h (6900 cycles with 100% retention) among HATN-based cathodes. The cathode also exhibits activity and stability in Mg and Al batteries, further proving HATNHHTP@CNT a universal cathode. XPS, FT-IR and DFT calculations confirm the role of pyrazine groups as redox centers and ether bonds as structure stabilizers. The ultra-stable and universal HATNHHTP@CNT cathode opens a new door to designing robust organic electrodes for reliable and large-scale energy storage.

High-yield 2D porous carbon framework for high-performance supercapacitors with high withstanding voltage

Low energy density is the fatal shortcoming of supercapacitors. It is a great challenge to construct ultra-stable porous carbon which can withstand ultrahigh voltage larger than 2.7 V in organic electrolyte. Herein, 2D porous carbon framework (PCF) with high carbon yield of 22.2% is synthesized from sulfonated pitch by simple interfacial self-assembly and activation annealing strategy. It is bestowed with ultrathin thickness of 5 nm, high packing density of 0.541 g cm−3, high specific surface area of 2511 m2 g−1 and high sp2 carbon content of 89%. More importantly, it has low surface oxygen atom content of 9.74 at.% and the surface oxygen-containing functional groups mainly exist in the form of stable ether, quinone and carbonyl groups. Consequently, this PCF can successfully operate at ultrahigh voltage of 3.2 V and 3.5 V in TEABF4/PC and EMIMBF4 electrolytes, respectively. In TEABF4/PC electrolyte, it can obtain high Cg of 125 F g−1 at 50 mA g−1 with rate capacity C10/0.05 as high as 76%. Satisfactorily, it can maintain high performance throughout the cycle life with 94.3% capacitance retention at 2.5 A g−1 after 20,000 cycles. Additionally, the energy density up to 60.9 Wh kg−1 (32.9 Wh L−1) can be achieved in EMIMBF4 electrolyte.

Selective cleavage of lignin-derived diphenyl ether C-O bond over weakly acidic Ni/Nb2O5 catalyst

Selective cleavage of stable ether C-O bonds is particularly of significance for the valorization of lignin and designing high active and cheap catalysts attracts researchers to conduct a lot of investigations. The niobium species containing both Brønsted and Lewis acid sites can be applied in hydrodeoxygenation of diphenyl ether (DPE). It is important to regulate the acidity of niobium to achieve the selective cleavage of DPE without hydrodeoxygenation. Herein, the weakly acidic Ni/Nb2O5 prepared by an incipient wetness impregnation method could efficiently cleave C-O bonds of DPE without hydrodeoxygenation. DPE was completely converted and the yields of target products (cyclohexane and cyclohexanol) reached 90% under the coexistence of H2 and isopropanol. It was ascribed to the common hydrogen supply between H2 and isopropanol which could produce more active hydrogen. Acetone was detected in the solution after the reaction, demonstrating that a dehydrogenation reaction of isopropanol provided hydrogen. In addition, the turnover frequency (TOF) and the apparent activation energy (Ea) for catalytic hydrogenolysis of DPE revealed that Ni/Nb2O5 possessed higher activity than Co/Nb2O5 under the same conditions. The possible reaction pathways were also summarized and analyzed.

An approach for upgrading lignite to improve slurryability: Blending with direct coal liquefaction residue under microwave-assisted pyrolysis

As the composition of direct coal liquefaction residue (DCLR) is complex and difficult to handle, more importantly its dielectric properties are excellent, it is used as consumable wave-absorbents to enhance the microwave pyrolysis of lignite for slurryability improvement. The effects of the different additions of DCLR on the evolution of pyrolysis products were studied by using gas chromatography, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and low-temperature N2 adsorption analysis. The results indicated that microwave-assisted pyrolysis with DCLR was a promising method for improving slurryability of lignite and an effective method for utilizing DCLR. The introduced DCLR accelerated the heating rate of the process of microwave upgrading lignite, facilitating the decomposition of active oxygen-containing functional groups and aliphatic hydrocarbons and then their transformation into stable ether groups and aromatic structures. In the meantime, it was converted into gaseous products, mainly composed of H2, CO, and CH4, and solid products with high quality. Additionally, the cyclization and aromatization of organic structures were improved, as well as the order degree of aromatic systems, especially with 12 wt% of DCLR added. Furthermore, the existing and newly formed structures of micropores and mesopores in the upgraded lignite (UL) were remarkably reduced with the increase of DCLR contents. The re-absorption capacity was dramatically reduced and the slurryability of UL was improved as a result of the changes in chemical properties and pore structures. The maximum solid concentration of lignite water slurry (LWS) increased from 41.73 wt% to 65.42 wt% with lower pseudo-plasticity and static stability.

Photocatalytic Reductive C-O Bond Cleavage of Alkyl Aryl Ethers by Using Carbazole Catalysts with Cesium Carbonate.

Methods to activate the relatively stable ether C-O bonds and convert them to other functional groups are desirable. One-electron reduction of ethers is a potentially promising route to cleave the C-O bond. However, owing to the highly negative redox potential of alkyl aryl ethers (Ered < -2.6 V vs SCE), this mode of ether C-O bond activation is challenging. Herein, we report the visible-light-induced photocatalytic cleavage of the alkyl aryl ether C-O bond using a carbazole-based organic photocatalyst (PC). Both benzylic and non-benzylic aryl ethers underwent C-O bond cleavage to form the corresponding phenol products. Addition of Cs2CO3 was beneficial, especially in reactions using a N-H carbazole PC. The reaction was proposed to occur via single-electron transfer (SET) from the excited-state carbazole to the substrate ether. Interaction of the N-H carbazole PC with Cs2CO3 via hydrogen bonding exists, which enables a deprotonation-assisted electron-transfer mechanism to operate. In addition, the Lewis acidic Cs cation interacts with the substrate alkyl aryl ether to activate it as an electron acceptor. The high reducing ability of the carbazole combined with the beneficial effects of Cs2CO3 made this otherwise formidable SET event possible.

Oxidative etching mechanism of the diamond (100) surface

We performed density functional theory calculations with van der Waals corrections to elucidate diamond oxidation mechanism on the atomic-level which could lead to insights that will advance the improvement of nascent nanofabrication technologies. We developed a comprehensive theory of oxidative etching of the diamond (100) surface, from the adsorption of gas phase O2, including details of metastable adsorption states, intersystem crossing, and induced surface dereconstruction, to the desorption of CO and CO2, complete etching of the top surface layer and its subsequent stabilization. Oxygen adsorption induce C-dimer bond breaking through the formation of carbonyl structures at low surface coverage. At high surface coverage, adjacent carbonyls can transform into the more stable ether chain with small energy barrier requirement. A mix of carbonyl and ether will form in surfaces with defects, and several models of possible structures have been presented. CO desorption creates a point defect that serves as nucleation site for the preferred etching direction along [011], perpendicular to the top layer C-dimer bonds. We obtained a wide range of desorption activation energies, which depend on the existence of point defects and reconstruction of surfaces. C-dimer formation and oxygen adsorption stabilize vacancies and single-atomic-layer-deep trough.

Functionalized Organosolv Lignins Suitable for Modifications of Hard Surfaces.

Two different organosolv lignins (OSLs), that is, wheat straw and corn stover OSLs, were chemically and enzymatically functionalized. Functional groups were attached via the formation of stable ether bonds exploiting the reactivity of free phenolic OH groups along the lignin backbone. The functional groups introduced a range from compact charged and chargeable building blocks for the generation of surface-active lignins to oligomeric and polymeric species used in lignin block-copolymer productions. Combination of selected functions led to novel charged or chargeable polymeric lignin-based materials. Products could be realized with different degrees of technical loadings in terms of introduced functional groups.

Research on a new composite hydrogel inhibitor of tea polyphenols modified with polypropylene and mixed with halloysite nanotubes

Considering drawbacks such as the low inhibition efficiency and short inhibition life of an existing pure hydrogel, a new physicochemical composite hydrogel inhibitor was developed. First, tea polyphenol radicals were grafted and polymerized onto a hydrogel and then mixed with HNTs (halloysite nanotubes). Electron microscopy, Fourier transform infrared spectrometry and thermal gravimetric analysis were used to analyze the inhibiting effect and mechanism of the composite hydrogel inhibitor. Research shows that (i) the graft copolymerization of tea polyphenols with acrylate will increase the contact area between the grafted gels and the surroundings, thus improving the water absorption capability of the hydrogel; (ii) the added tea polyphenols reduce the content of hydroxyl in coal and the content of carboxyl and carbonyl generated during the oxidation of aliphatic groups and it also increase the content of stable ether bond; and (iii) by absorbing the combustible gases and producing water, HNTs can shorten the exothermic temperature range (From 120.22 ℃ to 572.22 ℃) of coal sample processed by composite hydrogel, and it can reduce the release of heat, which is 2536.73 J/mg. These results suggest that the composite hydrogel can distinctly inhibit the spontaneous combustion and oxidation of coal, achieving stable inhibition in many aspects such as its physics, chemistry and thermal stability during the whole process of spontaneous combustion.

Comparison of the staged inhibitory effects of two ionic liquids on spontaneous combustion of coal based on in situ FTIR and micro-calorimetric kinetic analyses

Abstract The inhibitory effects of two ionic liquids (ILs), ethyltributylphosphonium bromide ([P4,4,4,2]Br) and the hydroxyl functional 1-hydroxyethyl-3-methyl imidazolium tosylate ([Hemim]Tos), on spontaneous combustion of coal were investigated and compared. The changes in various active functional groups of coal under IL inhibition were measured by in situ FTIR and analysed semi-quantitatively. Additionally, the impact of the ILs on the heat release rate of coal oxidation was examined by a micro-calorimetric technique. Subsequently, kinetic calculations were employed to elucidate the changes in the intrinsic mechanism of coal oxidation in the presence of ILs. The results revealed that [P4,4,4,2]Br and [Hemim]Tos exhibited distinctive inhibition characteristics on spontaneous combustion of coal. [P4,4,4,2]Br significantly reduced the associative hydroxyl group of coal by destroying the hydrogen bonds and forming stable ether structures. This kind of IL manifested significant inhibition of heat release at the slow oxidation stage of spontaneous combustion of coal. On the other hand, the reductive [Hemim]Tos afforded hydrogen ions from the functionalised O H bonds to eliminate the reactivity of the peroxide radicals. This led to a reduction in the formation of C O double bond intermediates in the transition and rapid oxidation stages at higher temperatures.