Oxygen Species Research Articles

Synergistic Effect of MIL-101/Reduced Graphene Oxide Nanocomposites on High-Pressure Ammonia Uptake.

Ammonia has emerged as a potential working fluid in adsorption heat pumps (AHPs) for clean energy conversion. It would be necessary to develop an efficient adsorbent with high-density ammonia uptake under high gas pressures in the low-temperature range for waste heat. Herein, a porous nanocomposite with MIL-101(Cr)-NH2 (MIL-A) and reduced graphene oxide (rGO) was developed to enhance the ammonia adsorption capacity over high ammonia pressures (3–5 bar) and low working temperatures (20–40 °C). A one-pot hydrothermal reaction could form a two-dimensional sheet-like nanocomposite where MIL-A nanoparticles were well deposited on the surface of rGO. The MIL-A nanoparticles were shown to grow on the rGO surface through chemical bonding between chromium metal centers in MIL-A and oxygen species in rGO. We demonstrated that the nanocomposite with 2% GO showed higher ammonia uptake capacity at 5 bar compared with pure MIL-A and rGO. Our strategy to incorporate rGO with MIL-A nanoparticles would further be generalizable to other metal–organic frameworks for improving the ammonia adsorption capacity in AHPs.

Multifunctional thermo-sensitive hydrogel for modulating the microenvironment in Osteoarthritis by polarizing macrophages and scavenging RONS

Osteoarthritis (OA) is a common degenerative joint disease that can lead to disability. Blocking the complex malignant feedback loop system dominated by oxidative stress and pro-inflammatory factors is the key to treating OA. Here, we develop a multifunctional composite thermo-sensitive hydrogel (HPP@Cu gel), which is utilized by Poloxamer 407 (P407) and hyaluronic acid (HA) mixture as the gel matrix, then physically mixed with copper nanodots (Cu NDs) and platelet-rich plasma (PRP). Cu NDs is a novel nano-scavenger of reactive oxygen and nitrogen species (RONS) with efficient free radical scavenging activity. HPP@Cu gel is injected into the articular cavity, where it form an in situ gel that slowly released Cu NDs, HA, and PRP, prolonging the duration of drug action. Our results indicate that HPP@Cu gel could efficiently remove RONS from inflammatory sites and promote repolarization of macrophages to an anti-inflammatory phenotype. The HPP@Cu gel therapy dramatically reduces cartilage degradation and inflammatory factor production in OA rats. This study provides a reliable reference for the application of injectable hydrogels in inflammatory diseases associated with oxidative stress.Graphical

Corrosion Assessment for Aging Treatment of Rolled and Selective Laser Melting 18Ni 300 Maraging Steel

In this study, we investigate the microstructure and the corrosion performance of an 18Ni 300 maraging steel after prepared by selective laser melting (SLM) technique and the effects of aging. The commercial 18Ni 300 maraging steel fabricated by rolling followed by aging acts as a comparison. The SLM specimens showed fine microstructures with homogeneous cellular and columnar dendrites, which resulted in relatively uniform corrosion, while the conventionally rolled specimens displayed a typical lath martensite microstructure. The aging treatment accelerated the corrosion rate possibly due to the galvanic corrosion between intermetallic precipitates Ni3(Ti, Mo) and martensite matrix, as well as the corrosion of Ni and Co which diffuses into the matrix. The formation of unmelted particles made of (Al, Ti)O during the SLM process is deleterious to the corrosion resistance as they lead to localized attack. The long-term immersion makes for the accumulation of thick and corrosion product layer, which prevents further dissolution of the metal substrate by preventing oxygen and ion species from contacting metals.

Al‐modified Mesoporous SiO2‐matrix‐supported Uniform CeO2 Nanodots with Superior Catalytic Efficiency in DCE Combustion

AbstractAdjusting the acidity and/or oxygen species on the surface of metal oxide nanostructures could fabricate the high active and durable catalysts for the combustion of chlorinated volatile organic compounds (CVOCs). Herein, Al‐modified mesoporous SiO2 matrix supported uniform CeO2 nanodots (CeO2@xAlSiO2) was synthesized and evaluated in dichloroethane (DCE) catalytic combustion. From the systematic study of the texture structure, surface properties, and catalytic activity, we deduced that the improved surface acidity and oxygen species activity enhanced the DCE conversion and reduced the formation of chlorinated organic byproduct, while increasing the formation of the desired product, HCl. The optimized CeO2@0.5AlSiO2 sample showed superior activity (90 % conversion of DCE at 260 °C), excellent durability (at 280 °C for 60 h) and good tolerance towards moisture (in 1 % and 3 % moisture for 10 h, respectively). Our work identified the important role of surface acidity and oxygen species over these functionalized catalysts, providing guidance for the advanced catalyst design.

A novel SRSF3 inhibitor, SFI003, exerts anticancer activity against colorectal cancer by modulating the SRSF3/DHCR24/ROS axis

As the modulation of serine/arginine-rich splicing factor 3 (SRSF3) may be therapeutically beneficial to colorectal cancer (CRC) treatment, the identification of novel SRSF3 inhibitors is highly anticipated. However, pharmaceutical agents targeting SRSF3 have not yet been discovered. Here, we propose a functional SRSF3 inhibitor for CRC therapy and elucidate its antitumor mechanisms. We found high expression of SRSF3 in 70.6% CRC tissues. Silencing SRSF3 markedly inhibits the proliferation and migration of CRC cells through suppression of its target gene 24-dehydrocholesterol reductase (DHCR24). This is evidenced by the links between SRSF3 and DHCR24 in CRC tissues. The novel SRSF3 inhibitor SFI003 exhibits potent antitumor efficacy in vitro and in vivo, which drives apoptosis of CRC cells via the SRSF3/DHCR24/reactive oxygen species (ROS) axis. Moreover, SFI003 is druggable with suitable pharmacokinetic properties, bioavailability, and tumor distribution. Thus, SRSF3 is a novel potential therapeutic target for CRC. Its inhibitor SFI003 may be developed as an anticancer therapeutic.

Histidine and Humans Disease

Background: Histidine is an important amino acid with important properties that enable it to play a vital part in many activities in the human body, such as proton buffering, metal ion chelation, scavenging of reactive oxygen and nitro-gen species, erythropoiesis and the histaminergic system. This review presents the impact of histidine level fluctuation on the body function, the physiological role and metabolic pathway of histidine in various parts of the human's body. Also, we investigated that histamine produc-tion by Histidine decarboxylase gene and there is relationship between histidine food intake and level of Histamine in blood, which resulting in the obesity, anemia and other nutrition issues. In addition, a neurotrans-mitter is included oin histamine that is widely distributed throughout the human brain; its deficiency could cause problems in the nervous system. This study revealed that deficiency of histidine contributed to mental problems like Parkinson's disease (PD), schizophrenia (SCZ), kidney and prion disease as well. As a result, histidine is important to keep hu-man body healthy, and it is also found that hisidine is used as a suitable drug for people who have schizophrenia. This review revealed that the correlation between histamine and asthma is still not well understood. So, this review will open way for researchers to focuses on this aspect. Keywords: Histidine, Histamine, physiological role, Parkinson's disease and human disease

INDUCTION OF NRF2 TRANSCTIPTION FACTOR INHIBITS FORMATION OF RACTIVE OXYGEN AND NITROGEN SPECIES IN LIVER OF RATS UNDER MODELLING METABOLIC SYNDROME BY EXPOSURE TO ROUND-THE-CLOCK LIGHTING

Aim: To evaluate the effect of dimethyl fumarate, an Nrf2 inducer, on the production of reactive oxygen and nitrogen species in the liver of rats under the conditions of modeling the metabolic syndrome with roundthe-clock illumination. Dimethyl fumarate in 10% dimethyl sulfoxide solution in a dose of 15 mg/kg was administered intraperitoneally to white rats over the modeled metabolic syndrome (a 20% aqueous fructose solution for drinking and a diet enriched with carbohydrates and lipids). In the liver homogenate of rats, the rate of generation of the superoxide anion radical (•О 2 ), the activity of total NO synthase (NOS), its constitutive and inducible isoforms (cNOS, iNOS), and the content of peroxynitrites of alkali and alkaline earth metals were determined. The administration of dimethyl fumarate under the experimental conditions significantly restrained the •О 2 production by microsomes and NOS in the liver tissues by 48.9%, by mitochondria by 47.3%, by leukocyte NADPH oxidase by 45.6%; it also reduced NOS activity (total and iNOS) by 33.1% and 35.9%, respectively, and the concentration of peroxynitrites by 39.7% compared with the values of the control group that received only the solvent (10% dimethyl sulfoxide solution). The cNOS activity and coupling index exceeded the control result in 2.95 and 5.5 times, respectively. The introduction of the Nrf2 inductor, dimethyl fumarate, during the simulation of the metabolic syndrome by round-the-clock lighting to rats is an effective means of limiting the production of reactive oxygen and nitrogen species in the liver tissues.

DIAGNOSTIC SIGNIFICANCE OF OXIDATIVE STRESS IN PATIENTS WITH CORONARY HEART DISEASE

Abstract. Cardiovascular diseases remain the leading cause of death in recent decades worldwide, especially in developed countries. Cardiovascular pathology can begin with risk factors that can cause local vascular damage and end with systemic complications leading to organ failure and death, which makes it necessary to understand the biochemistry of events associated with the entire process of progression of cardiovascular diseases and is crucial for diagnosis, prevention and treatment. It is known that the state of blood vessels is influenced by multiple factors of hemodynamic conditions, extracellular signaling proteins, including interleukins, cytokines, and intracellular biochemical molecules, including reactive oxygen and nitrogen species. The aim of the work was to evaluate the factors of oxidative stress and antioxidant protection in patients with coronary heart disease. The study included 96 patients of working age with a verified diagnosis of coronary artery disease. Statistical analysis was carried out using the StatTech v. 2.6.5. To assess the diagnostic significance of quantitative signs in predicting a certain outcome, the method of analyzing ROC curves was used. The article presents data on the quantitative content of nitric oxide, myeloperoxidase, superoxide dismutase in the blood serum of patients with coronary heart disease (acute myocardial infarction and unstable angina pectoris), describes the relationship between changes in their level, and assesses the diagnostic significance of the studied parameters. The obtained data on the production of nitric oxide, myeloperoxidase and superoxide dismutase in patients with acute myocardial infarction and unstable angina indicate an important prognostic value of assessing oxidative stress and the antioxidant system for early risk stratification of adverse outcomes in patients with coronary heart disease.

Response of antioxidant defences of Microcystis aeruginosa (Cyanobacteria) to increased temperature

ABSTRACT Cyanobacteria have different defence mechanisms, which have improved over time, to avoid or mitigate oxidative stress by using antioxidants as reactive species scavengers. The objective of the present study was to evaluate the effects of increased temperature, over several days of exposure, on biomass, lipid damage, oxygen and nitrogen reactive species, and different antioxidants on Microcystis aeruginosa (harmful cyanobacteria). Unicellular cultures were exposed to elevated (29°C) and control (26°C) temperatures for 10 d. The temperature shift induced activation of enzymatic antioxidant system and changes in content of non-enzymatic antioxidants after 2 d of exposure to 29°C. This was responsible for a lower content of reactive species during the subsequent days. An increase in enzymatic antioxidant activity, depending on the exposure time, was observed. In addition, there was a differential non-enzymatic antioxidant response that was also time dependent, which could be important to counteract oxidative stress induced by increases in temperature. Overall, the initial increase in β carotene and astaxanthin content followed by an increased activity of catalase together with superoxide dismutase and glutathione S transferase activities allowed the cyanobacteria to counteract the oxidative stress induced, and improved their growth at the increased temperature. Our results increase the understanding of different antioxidant responses, integrating enzymatic and non-enzymatic protection mechanisms over time when exposing M. aeruginosa to heatwaves. The survival capacity of Cyanobacteria in drinking water supplies can have serious implications for the environment and human health.

Insight into the Viscosity–Structure Relationship of MnO–SiO2–MgO–Al2O3 Fused Submerged Arc Welding Flux

In this study, the influence of Al2O3 on the viscosity and structure of MnO–SiO2–MgO(–Al2O3) submerged arc welding fluxes was investigated. The results showed that the viscosity initially decreased and subsequently increased with increasing Al2O3 contents from 0 to 25 mass pct, which correlates well with the “V”-shaped variation trend of the activation energy. The enhanced (Q2 + Q3 + Al–O0)/(Q0 + Q1 + Al–O−) ratio indicated the continuous polymerization of the flux structure with higher Al2O3 contents, which was further confirmed by the distribution characteristics of various oxygen species. The variation trend may likely be attributed to the competing effects of the overall weakened bond energy and the enhanced degree of polymerization of the flux structure.

Titania crystal-plane-determined activity of copper cluster in water-gas shift reaction

It is critical to probe the effect of the crystal plane of TiO2 support on the water-gas shift reaction (WGSR). Density functional theory (DFT) and microkinetic modeling were performed to investigate the reaction mechanism and reaction kinetics of WGSR on copper cluster on Anatatse-TiO2(001), TiO2(100), TiO2(101) surfaces. The calculation results indicated that three TiO2-supported Cu catalysts mainly carry out carboxyl pathway and redox pathway because the hydroxyl and oxygen species can be largely stabilized, and the TiO2(001) supported copper cluster exhibits the best catalytic performance for WGSR compared with other crystal plane. Compared with the d-band center of Cu(111), the strong interaction between the copper cluster and TiO2 support exposed (001) and (100) crystal planes can make the d-band center of the upper atoms of copper cluster shift upward and the lower Cu atoms shift downward, which in turn leads to the strong adsorption strength of reactants and oxygenates, and further the catalytic performance of WGSR has been significantly improved. The essential reason for crystal plane effect of TiO2 on WGSR is the difference in the surface energy and the surface geometry. Specifically, the higher the surface energy of TiO2 reflected by the high concentration of unsaturated two-coordinate oxygen(O2c), which enhanced Cu-TiO2 interaction, and ultimately the better the catalytic performance of TiO2 crystal plane. This work not only reveals the effect of TiO2 crystal plane in WGSR, but also provides reliable guidance for its application in other catalysis fields.

A simple model catalyst study to distinguish the roles of different oxygen species in propane and soot combustion

It is important yet difficult to distinguish the specific roles of superficial Oxn- and interfacial lattice oxygen in catalytic combustion, especially over catalysts consisting of reducible metal oxides. In this study, based on the comparison of two natural counterparts with similar structure — CeO2 (an Oxn- generator) and Pr6O11 (a lattice oxygen contributor), it is suggested that the catalytic combustion of propane under lean-burn conditions followed a typical Mars-van Krevelen mechanism, in which catalyst lattice oxygen represented the dominant reactive phases while superficial Oxn- played negligible roles. As for soot combustion, adsorbed Oxn- represented more sustainable oxidants than lattice oxygen (drained easily at the beginning of the reactions). Such a comparison is readily achieved and widely applicable, which may shed light on the identification of dominant reactive phases for various oxidation reactions over oxide-based catalysts.

Perovskite Oxides in Catalytic Combustion of Volatile Organic Compounds: Recent Advances and Future Prospects

Volatile organic compounds are a kind of important indoor and outdoor air pollutants. In recent years, more and more attention has been paid to the ways of volatile organic compound elimination because of its potential long‐term effects on human health. Among the various available methods for volatile organic compound elimination, the catalytic combustion is the most attractive method due to its high efficiency, low cost, simple operation, and easy scale‐up. Perovskite oxides, as a large family of metal oxides with their A‐site mainly of lanthanide element and/or alkaline earth metal element and B‐site of transition metal element, have been extensively investigated as active and stable catalysts for volatile organic compound removal reactions due to their abundant compositional elements, high thermal/chemical stability, and compositional/structural flexibility. The catalytic performance of perovskite oxides is strongly depended on its material composition, morphology, and surface/bulk properties, while the doping, tailored synthesis route, and composite construction may have a significant effect on the bulk (oxygen vacancy concentration, lattice structure), surface (oxygen species, defect) properties, and particulate morphology, consequently the catalytic activity and stability for volatile organic compound removal. Herein, a comprehensive review about the recent advances in perovskite oxides for volatile organic compound elimination reactions based on catalytic combustion is presented from different aspects with a special emphasis on the material design strategies, such as compositional tuning, morphology control, nanostructure building, hybrid construction, and surface modification. At last, some perspectives are presented on the development and design of perovskite oxide‐based catalysts for volatile organic compound removal applications by highlighgting the critical issues and challenges.

Synthesis of Bi2O2CO3/In(OH)3·xH2O nanocomposites for isopropanol sensor with excellent performances at low temperature

The ability to detect a volatile organic compound in real-time, such as isopropanol (IPA) gas, is critical for human health and safety protection, especially since the sensor can operate at low temperatures and behave outstanding sensing performances. Herein, the Bi2O2CO3/In(OH)3·xH2O nanocomposites are synthesized using a two-step hydrothermal process, particularly the surfaces of Bi2O2CO3 (BCO) nanosheets were embellished with In(OH)3·xH2O nanoparticles. It is found that the BCO/In(OH)3·xH2O sensors exhibit an excellent response of 20.39, wide concentration detection range from 1 to 1000 ppm, the working temperature as low as 100 ºC, and the rapid response/recovery times of 5 s and 4 s towards 100 ppm IPA. On the other hand, the selectivity of the BCO/In(OH)3·xH2O sensor towards IPA is eye-catching. In particular, the enhanced IPA sensing performances might be attributed to the large specific area (52.46 m2/g). The increased conductivity of BCO/In(OH)3·xH2O nanocomposites due to incorporation of the In(OH)3·xH2O, which can significantly promote the surface-catalyzed reaction between oxygen species such as O- and IPA molecules.

Trimetallic Sulfide Hollow Superstructures with Engineered d-Band Center for Oxygen Reduction to Hydrogen Peroxide in Alkaline Solution.

High‐performance transition metal chalcogenides (TMCs) as electrocatalysts for two‐electron oxygen reduction reaction (2e‐ORR) in alkaline medium are promising for hydrogen peroxide (H2O2) production, but their synthesis remains challenging. In this work, a titanium‐doped zinc–cobalt sulfide hollow superstructure (Ti–ZnCoS HSS) is rationally designed as an efficient electrocatalyst for H2O2 electrosynthesis. Synthesized by using hybrid metal–organic frameworks (MOFs) as precursors after sulfidation treatment, the resultant Ti–ZnCoS HSS exhibits a hollow‐on‐hollow superstructure with small nanocages assembled around a large cake‐like cavity. Both experimental and simulation results demonstrate that the polymetallic composition tailors the d‐band center and binding energy with oxygen species. Moreover, the hollow superstructure provides abundant active sites and promotes mass and electron transfer. The synergistic d‐band center and superstructure engineering at both atomic and nanoscale levels lead to the remarkable 2e‐ORR performance of Ti–ZnCoS HSS with a high selectivity of 98%, activity (potential at 1 mA cm−2 of 0.774 V vs reversible hydrogen electrode (RHE)), a H2O2 production rate of 675 mmol h–1 gcat –1, and long‐term stability in alkaline condition, among the best 2e‐ORR electrocatalysts reported to date. This strategy paves the way toward the rational design of polymetallic TMCs as advanced 2e‐ORR catalysts.

One-pot synthesis of dual-phase manganese dioxide for toluene removal: Effect of crystal phase blending level on oxygen species and activity

A series of highly active manganese oxide with different oxygen species were synthesized by one pot method, wherein the active species were induced by in-situ combination of crystal phase. The scanning electron microscope (SEM) showed the successful combination of rodlike MnO2 and flowerlike MnO2. The x-ray diffraction (XRD) indicated an increase in the oxygen defects due to the in-situ assembly. Compared with that of pure α-MnO2 and β-MnO2, the combined-phase xα/yβ-MnO2 ((x, y represents the molar ratio of α and δ) presented the higher activities for the catalytic oxidation of toluene. Through the analysis of X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction with hydrogen (H2-TPR) technologies, the order of catalytic activity was completely consistent with the change trend of the hydrogen consumption and the molar ratio of adsorbed oxygen/lattice oxygen (Oads/Olatt), showing that the high catalytic activities of catalysts were main attributed to their more low-valent manganese and high content of adsorbed oxygen. Moreover, the intermediates of toloune oxidation over α/β-MnO2 with the best catalytic activity were detected by in-situ diffuse reflectance FTIR spectroscopy (DRIFTS), and the by-products in the exhaust gases were detected by a thermal desorption/gas chromatograph mass spectrometer (TD/GC–MS), which confirmed the presence of the intermediates. Furthermore, the catalytic mechanism and degradation path of toluene oxidation have been studied in depth. Finally, the effect of moisture on catalytic activity of α/δ-MnO2 for toluene oxidation were also discussed.

Photodegradation of Congo Red by Modified P25-Titanium Dioxide with Cobalt-Carbon Supported on SiO2 Matrix, DFT Studies of Chemical Reactivity

Congo red is a hazardous material in the environment. The present work describes the synthesis of TiO2/CoC@SiO2-bipy (1) and TiO2/CoC@SiO2-phen (2) nanocomposites for the photodegradation of azo-dye Congo red (CR) dye in aqueous solution, by combining pure TiO2 with CoC@SiO2-bipy (s1) and CoC@SiO2-phen (s2) nanoparticles. The prepared nanocomposites were evaluated in term of photocatalytic activity rates in aqueous solution using CR. The nanocomposites TiO2/CoC@SiO2-bipy (1) and TiO2/CoC@SiO2-phen (2) were prepared from TiO2 (75%) and CoC@SiO2-bipy (s1) or CoC@SiO2-phen (s2) (25%) (weight ratio). Ultra-sonication and milling were used to prepare the heterogeneous nano catalysts. The pH, initial dye concentration, and catalyst dosage appeared to have a significant impact on the photocatalytic degradation performance. Molecular oxygen and other active species played a significant role in the photocatalyst degradation of CR with sunlight energy (UV-index 5.0). The chemical reactions were accelerated depending upon electrophilicity (ω) and energy gap (Eg) of azo dye species CR-N=N, CR-N=NH and CR=N-NH species which were calculated by density function theory (DFT). It can be concluded that the rate of electron–hole recombination of the TiO2 catalyst, when adding CoC@SiO2-bipy (s1) or CoC@SiO2-phen (s2), not only enhances the degradation but also effectively removes toxic dye molecules and their by-products. The newly prepared TiO2/CoC@SiO2-bipy (1) nanocomposites showed increased photocatalytic efficiency at low catalyst dose and faster rate of degradation of Congo red compared to TiO2/CoC@SiO2-phen (2) and TiO2 catalysts. The novel catalysts (1) and (2) can be easily separated by centrifugation and filtration, from the reaction mixture compared to TiO2.

A critical evaluation of barium silicate glass network polymerization

The state of polymerization in barium silicate glasses (xBaO·(1-x)SiO2, 0.28 ≤ x ≤ 0.45) has been studied by both experiment (Raman, static and MAS 29Si NMR spectroscopy) and molecular dynamics simulations (Vashishta-Rahman and Du-Cormack potentials). No a priori assumptions were made about the number of Qn species, specific mean polymerization nor presence or absence of ‘free’ oxygen species. This allowed us to test the relationships between these structural aspects.The Qn site interconversion equilibrium constants KQ2 and KQ3 were found to be 0.07 and 0.05±0.02 from static 29Si NMR, and 0.14±0.07 and 0.07±0.01 from 29Si MAS NMR, respectively. The Qn species distribution was used to determine the Raman scattering cross-sections for Q1, Q2 and Q3 as 1.01±0.15, ∼1.1, and 1.14±0.04, respectively, although some compositional dependence was found. The Q4 cross-section displays a unique behavior approaching 0 at 38% BaO. This more accurate structural framework paves the way for future studies to establish meaningful structure−property relationships for these glasses.

Introduced oxygen vacancies in cadmium ferrite anode materials via Zn2+ incorporation for high performance lithium-ion batteries

Cationic substitution strategy was recognized as an effective approach to create a defective structure and increase the oxygen vacancies in the crystal structure for improving the electrochemical performance of Li-ion batteries components. In this study, ZnxCd1-xFe2O4 nanoparticles were synthesized via a facile inexpensive process at low temperature. The collected XRD data confirmed the formation of cubic structure with Fd3m space group. HR-TEM investigations showed the size enlargement of spherical-like crystals with increasing the concentration of doping Zn2+ ion. FESEM and BET measurements indicated the conversion of micropores in pure CdFe2O4 into mesopores and macropores in Zn-doped CdFe2O4 samples. XPS results of O1s spectra elucidated that Zn-doped CdFe2O4 samples have higher conductivity due to the created lattice defects and oxygen species. Zn-doped CdFe2O4 anodes exhibit great improvement in their initial discharge capacities ∼1618 and 1880 mAhg−1 upon substitution of Cd with 5% and 10% Zn, respectively. Furthermore, 10% Zn-doped CdFe2O4 anode displayed the highest Li-ions diffusion coefficient and exchange current density due to the enhanced Li+ ions mobility. The increase in zinc content (0.0–0.1) led to a decrease in the DC activation energy from 0.11 to 0.09 eV.

A theoretical investigation into the comparative adsorption between dissolved oxygen and oxygenate species on zeolite 3.7 Å during aviation fuel treatment for thermal stability improvement

In this work we present a theoretical investigation to promote our understanding of the underlying processes of chabazite supported fuel treatment to improve thermal stability at the laboratory scale. It has been shown in prior work that zeolites can remove oxygenated heteroatomic species as well as molecular oxygen from fuel. This work investigates the molecular interaction of the aforementioned species with zeolite to provide a theoretical framework to robustly describe the experimentally observed behaviour. The ab initio quantum chemistry calculations show that a variety of interactions can occur. This work correlates observed enthalpy changes between different oxygenated species and oxygen to their propensity to be removed from the fuel during zeolite treatment which can act as a predictor for the propensity of contaminants to be removed by the zeolite.