Fourier-transform Spectroscopy Research Articles

Detection of a C4 Criegee Intermediate: Fourier-Transform Microwave Spectroscopy of Methacrolein Oxide.

Pure rotational transitions of methacrolein oxide (MACRO) were observed by Fourier-transform microwave spectroscopy. Among the four low-lying conformers existing within an energy window of 3 kcal/mol, only the lowest-energy conformer, the anti-trans conformer, was detected in a discharged jet of a 1,3-diiode-2-methylprop-1-ene and O2 mixture diluted in Ar. Nineteen pure rotational transitions, in the frequency range from 10 to 25 GHz, most of them showing A/E splitting due to the methyl-top internal rotation, were observed and analyzed by the XIAM program, yielding the internal rotation barrier of 559 cm-1, which very well agrees with a theoretically calculated value, 558 cm-1, at the CCSD(T)/cc-pVTZ level of theory.

Insights into the Sensing Mechanism of a Metal-Oxide Solid Solution via Operando Diffuse Reflectance Infrared Fourier Transform Spectroscopy.

Recently, the influence of Nb addition in the oxide solid solution of Sn and Ti was investigated with regard to the morphological, structural and electrical properties for the production of chemoresistive gas sensors. (Sn,Ti,Nb)xO2-based sensors showed promising features for ethanol monitoring in commercial or industrial settings characterized by frequent variation in relative humidity. Indeed, the three-metal solid solution highlighted a higher response level vs. ethanol than the most widely used SnO2 and a remarkably low effect of relative humidity on the film resistance. Nevertheless, lack of knowledge still persists on the mechanisms of gas reaction occurring at the surface of these nanostructures. In this work, operando Diffuse Reflectance Infrared Fourier Transform spectroscopy was used on SnO2- and on (Sn,Ti,Nb)xO2-based sensors to combine the investigations on the transduction function, i.e., the read-out of the device activity, with the investigations on the receptor function, i.e., compositional characterization of the active sensing element in real time and under operating conditions. The sensors performance was explained by probing the interaction of H2O and ethanol molecules with the material surface sites. This information is fundamental for fine-tuning of material characteristics for any specific gas sensing applications.

The Rapid Detection of Trash Content in Seed Cotton Using Near-Infrared Spectroscopy Combined with Characteristic Wavelength Selection

Herein, we propose a new method based on Fourier-transform near-infrared spectroscopy (FT-NIR) for detecting impurities in seed cotton. Based on the spectral data of 152 seed cotton samples, we screened the characteristic wavelengths in full-band spectral data with regard to potential correlation with the trash content of seed cotton. Then, we applied joint synergy interval partial least squares (siPLS) and combinatory algorithms with the competitive adaptive reweighted sampling method (CARS) and the successive projection algorithm (SPA). In addition, we used the sparrow search algorithm (SSA), gray wolf algorithm (GWO), and eagle algorithm (BES) to optimize parameters for support vector machine (SVM) analysis. Finally, the feature wavelengths optimized via the six feature wavelength extraction algorithms were modeled and analyzed via partial least squares (PLS), SSA-SVM, GWO-SVM, and BES-SVM, respectively. The correlation coefficients, Rc and Rp, of the calibration and prediction sets were subsequently used as model evaluation indices; comparative analysis highlighted that the preferred option was the inverse estimation model as this could accurately predict the trash content of seed cotton. Subsequently, we found that the accuracy of predicting the content of impurities in seed cotton when applying the optimized SVM model of SSA combined with the feature wavelengths screened via siPLS-SPA was optimal. Thus, the optimal modeling method for inverse impurity content was siPLS-SPA-SSA-SVM, with an Rc value of 0.9841 and an Rp value of 0.9765. The rapid application development (RPD) value was 6.7224; this is >3, indicating excellent predictive ability. The spectral inversion model for determining the impurity rate of mechanized harvested seed cotton samples established herein can, therefore, determine the impurity rate in a highly accurate manner, thus providing a reference for the subsequent construction of a portable spectral detector of impurity rate. This will help objectively and quantitatively characterize the impurity rate of mechanized harvested seed cotton and provide a new tool for rapidly detecting impurities in mechanized harvested wheat. Our findings are limited by the small sample size and the fact that the model developed for estimating the impurity content of seed cotton was specific to a local experimental field and certain varieties of cotton.

Validation of Version 1.3 Ozone Measured by the SOFIE Instrument

AbstractThe Solar Occultation for Ice Experiment (SOFIE) has operated aboard the Aeronomy of Ice in the Mesosphere (AIM) satellite since 2007. SOFIE uses solar occultation to retrieve ozone (O3) profiles from ∼20 to 100 km altitude, typically at polar latitudes. This study validates SOFIE O3 profiles, including error analysis and comparisons with independent observations. Comparisons are made to the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE‐FTS) and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) satellite instruments. SOFIE shows qualitative and quantitative agreement with both data sets between 30 and 70 km and better overall agreement in the northern hemisphere. SOFIE and ACE mean differences are typically within 20% in the 30–70 km altitude range. SOFIE and MIPAS exhibit mean difference values within 30% in the winter and 20% for all other seasons averaged, between ∼30 and 60 km. Seasonal comparisons indicate similar variations in both hemispheres and through all seasons. The comparisons indicate that SOFIE is biased 5%–10% low at 30–70 km altitudes, with greater differences at higher and lower altitudes. The comparisons are challenging due to the low O3 concentrations at high altitudes, the limited number of coincidences, and the large diurnal variation in mesospheric O3 during twilight hours.

The effective monitoring of eleven crucial parameters that describe the condition of cultivated Haplic Luvisol soils using fourier-transformed near-infrared spectroscopy

The study aimed to develop a cost-effective and rapid approach for monitoring eleven crucial parameters that describe the health of cultivated Haplic Luvisol soils. To achieve this, the diffuse reflectance spectra in the NIR spectral region, between 1100 and 2500 nm, were registered, and partial least-squares (PLS) models to predict the concentrations of the critical parameters, including organic carbon, total nitrogen, the available soil nutrients (phosphorus, potassium and magnesium), the exchangeable cations (calcium, magnesium and potassium), the pH levels (determined in deionized water or KCl solution and hydrolytic acidity), were built. The validation results, which are expressed as RMSE and R2val that were obtained for validation the samples, demonstrate that the proposed approach is a reliable and efficient way to monitor the health of Haplic Luvisol soils. Specifically, excellent predictions were obtained for the total nitrogen, organic carbon and pH, which was determined in KCl solution with R2val values equal to 0.9696, 0.9573 and 0.9176, respectively. Additionally, very good PLS models were constructed to estimate the pH levels determined in deionized water, exchangeable magnesium, and potassium, which achieved R2val values of 0.8650, 0.8383, and 0.8329, respectively. For the remaining parameters, the corresponding R2val values were above 0.7294.

Selective anomer crystallization from aqueous solution: Monitoring lactose recovery under mutarotation limitation via attenuated total reflection Fourier-transform spectroscopy and theoretical rate analysis

Lactose is typically produced via cooling crystallization either from whey or whey permeate (edible grade) or from aqueous solution (pharmaceutical grade). While in solution, lactose is present in 2 anomeric forms, α- and β-lactose. During cooling crystallization under standard process conditions, only α-lactose crystallizes, depleting the solution of α-anomer. In practice, mutarotation kinetics are often assumed to be much faster than crystallization. However, some literature reports limitation of crystallization by mutarotation. In the present research, we investigate the influence of operating conditions on mutarotation in lactose crystallization and explore the existence of an operation regimen where mutarotation can be disregarded in the crystallization process. Therefore, we study crystallization from aqueous lactose solutions by inline monitoring of concentrations of α- and β-lactose via attenuated total reflection Fourier-transform spectroscopy. By implementing a linear cooling profile of 9 K/h to a minimum temperature of 10°C, we measured a remarkable increase in β/α ratio, reaching a maximum of 2.19. This ratio exceeds the equilibrium level by 36%. However, when the same cooling profile was applied to a minimum temperature of 25°C, the deviation was significantly lower, with a maximum β/α ratio of 1.72, representing only an 8% deviation from equilibrium. We also performed a theoretical assessment of the influence of process parameters on crystallization kinetics. We conclude that mutarotation needs to be taken into consideration for efficient crystallization control if the crystal surface area and supersaturation are sufficiently high.

Design optimization and implementation of a Fourier transform spectrometer with rotating motion for 0.1 cm-1 resolution spectroscopy.

In this paper, we present the design optimization and implementation of a high-resolution near-infrared Fourier transform spectrometer (FTS) based on a rotating motion. The FTS system incorporates a rotating mirror-pair for scanning the optical path length (OPL). The design optimization process is performed to maximize the scanning range to obtain a resolution of 0.1 cm-1 while taking into account constraints on the volume of the system and the availability of commercial optics. By using a pattern search algorithm, we optimized the geometrical parameters of the rotating part, and found the best solution to satisfy the constraints. A data processing method is implemented to correct the nonlinear OPL scanning using a He-Ne laser. The performance of the implemented FTS is verified through spectral analysis within the spectral range of 1550 ± 25 nm. This spectral band corresponds to the wavelength range of the amplified spontaneous emission (ASE) obtained from an Er-doped fiber amplifier used in this study. Additionally, gas spectroscopy conducted using the FTS system successfully detects and analyzes the distinct absorption lines of hydrogen cyanide in 16.5 cm gas cell. The detection sensitivity of a single measurement is evaluated based on the noise equivalent absorption coefficient of 1.45 × 10-5 cm-1 Hz-1/2 calculated from 5-sec measurement time, 2000 spectral elements, and 208 signal-to-noise ratio with 0.2 scan/sec.

Application of a manganese dioxide/amine-functionalized metal-organic framework nanocomposite as a bifunctional adsorbent-catalyst for the room-temperature removal of gaseous aromatic hydrocarbons

A high surface area (883 m2·g−1) nanocomposite composed of an amine-functionalized metal–organic framework (NH2-UiO-66 (U6N)) and manganese dioxide (MnO2@U6N) was prepared as bifunctional adsorbent-catalyst for the purification of multiple aromatic volatile organic compounds (VOCs) such as benzene (B), toluene (T), m-xylene (X), and styrene (S), i.e., BTXS. The performance of MnO2@U6N was assessed for BTXS removal both as single- and multi-component systems at room temperature (RT (20 °C)) under dark conditions. MnO2@U6N exhibited superior catalytic-adsorption activity for the RT removal of BTXS. The removal performance of MnO2@U6N against BTXS was then assessed across varying levels of flow rate, VOC concentration, adsorbent/catalyst mass, and relative humidity. To better understand the catalytic-adsorption activity, two types of non-linear kinetic models (pseudo-first-order and pseudo-second-order) were utilized to simulate the experimentally obtained data. In-situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) analysis was also conducted to interpret the removal mechanism of BTXS. Their adsorption capacity (mg·g−1) values are estimated to increase in the order of B (21.1) < T (66.0) < X (79.1) < S (129.7). It is suggested that the adsorbed aromatic VOC molecules on the surface of MnO2@U6N should react with active oxygen species (lattice and adsorbed oxygen) to yield the environmentally benigh end products (i.e., carbon dioxide and water) along with various intermediates (e.g., alkoxides, aldehydes, phenolates, carboxylates, and anhydrides). Accordingly, the VOC removal potential of MnO2@U6N has been validated through the synergistic combination between adsorption (primary process) and catalysis (subordinate process) at RT.

Calcination and ion substitution improve physicochemical and biological properties of nanohydroxyapatite for bone tissue engineering applications

Nanohydroxyapatite (nanoHAP) is widely used in bone regeneration, but there is a need to enhance its properties to provide stimuli for cell commitment and osteoconduction. This study examines the effect of calcination at 1200 °C on the physicochemical and biological properties of nanoHAP doped with magnesium (Mg2+), strontium (Sr2+), and zinc (Zn2+). A synergistic effect of dual modification on nanoHAP biological properties was investigated. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), BET analysis, Fourier-transform spectroscopy, and thermal analysis methods. Furthermore, ion release tests and in vitro biological characterization, including cytocompatibility, reactive oxygen species production, osteoconductive potential and cell proliferation, were performed. The XRD results indicate that the ion substitution of nanoHAP has no effect on the apatite structure, and after calcination, β-tricalcium phosphate (β-TCP) is formed as an additional phase. SEM analysis showed that calcination induces the agglomeration of particles and changes in surface morphology. A decrease in the specific surface area and in the ion release rate was observed. Combining calcination and nanoHAP ion modification is beneficial for cell proliferation and osteoblast response and provide additional stimuli for cell commitment in bone regeneration.

Plasma Polymerization of Precipitated Silica for Tire Application.

Pre-treated silica with a plasma-deposited (PD) layer of polymerized precursors was tested concerning its compatibility with Natural Rubber (NR) and its influence on the processing of silica-silane compounds. The modification was performed in a tailor-made plasma reactor. The degree of deposition of the plasma-coated samples was analyzed by ThermoGravimetric Analysis (TGA). In addition, Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFTs), X-ray Photoelectron Spectroscopy (XPS), and Transmission Electron Microscopy (TEM) were performed to identify the morphology of the deposited plasma polymer layer on the silica surface. PD silica samples were incorporated into a NR/silica model compound. NR compounds containing untreated silica and in-situ silane-modified silica were taken as references. The silane coupling agent used for the reference compounds was bis-(3-triethoxysilyl-propyl)disulfide (TESPD), and reference compounds with untreated silica having the full amount and 50% of silane were prepared. In addition, 50% of the silane was added to the PD silica-filled compounds in order to verify the hypothesis that additional silane coupling agents can react with silanol groups stemming from the breakdown of the silica clusters during mixing. The acetylene PD silica with 50% reduced silane-filled compounds presented comparable properties to the in-situ silane-modified reference compound containing 100% TESPD. This facilitates processing as lower amounts of volatile organic compounds, such as ethanol, are generated compared to the conventional silica-silane filler systems.

New acetylene line list near 3.8-μm – Part II

The investigation of the 3.8 µm spectral region of acetylene 12C2H2 main isotopologue has been completed from spectra recorded with Fourier Transform Spectrometer (FTS) using high optical path length. This work is the second of a series dedicated to the ΔP = 4 spectral region. In the first paper of the series (JQSRT 2023;295:108413) 14 bands of 12C2H2 were studied in the beginning of the region. In the present work the whole ΔP = 4 spectral region was investigated. 52 newly observed vibrational bands have been studied as well as the 5 intense bands present in the HITRAN and GEISA databases. The band centers and the upper level spectroscopic constants were retrieved for all bands. The comparison with the data from HITRAN and GEISA databases revealed important deviations from the measurements due to wrong extrapolations (especially line positions). The effective dipole moment operator parameters describing intensities of all transitions observed in the ΔP = 4 spectra region were refined. A complete list of calculated line parameters for 7515 transitions has been generated for 71 bands between 2389 cm−1 and 2890 cm−1.

Constraining the budget of atmospheric carbonyl sulfide using a 3-D chemical transport model

Abstract. Carbonyl sulfide (OCS) has emerged as a valuable proxy for photosynthetic uptake of carbon dioxide (CO2) and is known to be important in the formation of aerosols in the stratosphere. However, uncertainties in the global OCS budget remain large. This is mainly due to the following three flux terms: vegetation uptake, soil uptake and oceanic emissions. Bottom-up estimates do not yield a closed budget, which is thought to be due to tropical emissions of OCS that are not accounted for. Here we present a simulation of atmospheric OCS over the period 2004–2018 using the TOMCAT 3-D chemical transport model that is aimed at better constraining some terms in the OCS budget. Vegetative uptake of OCS is estimated by scaling gross primary productivity (GPP) output from the Joint UK Land Environment Simulator (JULES) using the leaf relative uptake (LRU) approach. The remaining surface budget terms are taken from available literature flux inventories and adequately scaled to bring the budget into balance. The model is compared with limb-sounding satellite observations made by the Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS) and surface flask measurements from 14 National Oceanic and Atmospheric Administration – Earth System Research Laboratory (NOAA-ESRL) sites worldwide. We find that calculating vegetative uptake using the LRU underestimates the surface seasonal cycle amplitude (SCA) in the Northern Hemisphere (NH) mid-latitudes and high latitudes by approximately 37 ppt (35 %). The inclusion of a large tropical source is able to balance the global budget, but further improvement to the SCA and phasing would likely require a flux inversion scheme. Compared to co-located ACE-FTS OCS profiles between 5 and 30 km, TOMCAT remains within 25 ppt (approximately 5 % of mean tropospheric concentration) of the measurements throughout the majority of this region and lies within the standard deviation of these measurements. This provides confidence in the representation of atmospheric loss and surface fluxes of OCS in the model. Atmospheric sinks account for 154 Gg S of the annual budget, which is 10 %–50 % larger than previous studies. Comparing the surface monthly anomalies from the NOAA-ESRL flask data to the model simulations shows a root-mean-square error range of 3.3–25.8 ppt. We estimate the total biosphere uptake to be 951 Gg S, which is in the range of recent inversion studies (893–1053 Gg S), but our terrestrial vegetation flux accounts for 629 Gg S of the annual budget, which is lower than other recent studies (657–756 Gg S). However, to close the budget, we compensate for this with a large annual oceanic emission term of 689 Gg S focused over the tropics, which is much larger than bottom-up estimates (285 Gg S). Hence, we agree with recent findings that missing OCS sources likely originate from the tropical region. This work shows that satellite OCS profiles offer a good constraint on atmospheric sinks of OCS through the troposphere and stratosphere and are therefore useful for helping to improve surface budget terms. This work also shows that the LRU approach is an adequate representation of the OCS vegetative uptake, but this method could be improved by various means, such as using a higher-resolution GPP product or plant-functional-type-dependent LRU. Future work will utilise TOMCAT in a formal inversion scheme to better quantify the OCS budget.

Cerium-Biochar composite for the adsorptive and oxidative removal of Sunzol Black dye from aqueous solutions

The toxicity of industrial dyes in water being a major concern due to their high levels of contamination is a pressing issue. We studied the potential of a mesoporous Cerium/Biochar (nZVCe/BC) Corn extract composite to remove Sunzol Black (SB) dye from water. Advanced physical techniques were used to characterize the composite and found that it had a very high crystallinity surface area. The morphology and structure of the newly synthesized composite were thoroughly studied through, Fourier–Transform Spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy Dispersive X-Ray (EDX), and Brunner–Emmett-Teller (BET). The morphology of the newly synthesized nanocomposite (nZVCe/BC) appeared to be highly dispersed and uniform. To increase its removal efficiency, to investigate the catalytic potential of the composite with hydrogen peroxide (H2O2) and found that the OH radical generated by this process significantly enhanced the degradation of SB. The degradation of SB was hindered by the presence of hydroxyl radical scavengers. Using a combination of H2O2 and Ce/BC, the removal of SB increased from 65 to 85% after 90 min when [Ce]⁰, [SB], and [H2O2] were set to 0.5 g/L, 10, and 40 ppm, respectively. This was attributed to the hydroxyl radical, which has a high degree of reactivity. The synthesized Ce nanocomposite had a high surface area (16.82 m2/g) and achieved 63 % removal of SB dye within 85 min, when the starting concentrations of Ce and SB were 0.5 g/L and 10 parts-per-million (ppm), respectively. The impact of the pH of an aqueous solution on the removal of SB through photocatalytic processes was studied. It was found that the degradation of SB was hindered at both highly alkaline and highly acidic pH levels. The results showed that almost 90% of the SB was removed. Additionally, the removal pattern of SB was determined and the nature of the degradation products was identified.

Synthesis of bio-based diethyl pentane-1,5-diyldicarbamate via the carbonylation of pentanediamine with CO2 over a zirconium-doped CeO2 catalyst

Diethyl pentane-1,5-diyldicarbamate (PDC), a bio-based intermediate used for isocyanate and polyurethanes, was synthesized by the direct carbonylation of CO2 and pentanediamine (PDA) with 2-cyanopyridine (2-CP) over Zr-doped CeO2. In this study, Zr-doped CeO2 catalysts with different contents of Zr are successfully synthesized to produce PDC from PDA, CO2, and ethanol. Among them, Zr0.05Ce exhibits enhanced reaction activity and the productivity reached 6.0 mmol·g−1·h−1. Characterizations based on X-ray photoelectron spectroscopy, Raman, and CO2/NH3-temperature-programmed desorption prove that the doping of Zr atoms into CeO2 regulates the acid–base sites and promotes oxygen vacancy formation, which is primarily responsible for the formation of monoethyl carbonate, an intermediate for diethyl carbonate (DEC). In-situ diffuse reflectance Fourier-transform spectrometry and Fourier-transform infrared spectroscopy reveal that PDA reacts with 2-CP to form N, N'-(pentane-1,5-diyl)dipicolinamide, which are transformed into PDC. Finally, the catalytic activity could be regenerated after calcination. This study presents a green route for producing bio-based carbamate by constructing C-N bond using CO2 as a carbonyl source, which can replace carbamates derived from petrochemical resources in the future.

Influence of Lead Nanoparticles on Structural, Morphological, and Mechanical Characteristics of (SiR-PU/Micro-Pb) Composites and Radiation Shielding Applications

This research includes the manufacture of a polymeric nanocomposite consisting of silicone rubber/polyurethane as a base, with the addition of the first filler of micro-lead with a ratio of 300 pphr and the second filler of nano-lead with different ratios (0, 0.2, 0.4, 0.6, 0.8 pphr). With the addition of hexane (liquid state) to the superposition using the casting technique at room temperature. The structural properties of the surfaces of the samples were measured using Fourier transformation spectroscopy (FT-IR) and the scanning electron microscope (SEM). In addition to studying the mechanical properties represented by each hardness, tensile, elongation, and elastic modulus. (FT-IR) showed the absence of a chemical reaction for all samples. While SEM measurements showed a homogeneous distribution of micro-lead and nano-lead in the presence of hexane equally, and there were no voids in the eyes of the prepared rubber equally. For the mechanical properties, we see that the hardness, tensile strength and modulus of elasticity continue to improve with the increase in the number of lead nanoparticles. And a decrease in elongation as a result of inverse proportion to the modulus of elasticity. From the results obtained, this composite can be used in gamma ray attenuation applications in shielding, especially in medical and industrial fields.

Synthesis and characterization of nanobiochar from rice husk biochar for the removal of safranin and malachite green from water

Xenobiotic pollution in environment is a potential risk to marine life, and human health. Nanobiotechnology is an advanced and emerging solution for the removal of environmental pollutants. Adsorption-based technologies are being used to alleviate the global prevalence of xenobiotics like dyes, due to their high efficacy and cost effectiveness. Current study explored the potential of nanobiochar syntehsized via ultrasonication and centrifugation from rice husk for dye removal from water. It involves the synthesis of nanobiochar from rice husk biochar for removal of Safranin, Malachite green, and a mixture of both from aqueous water. Biochar was synthesized through pyrolysis at 600 °C for 2 h. To convert it into nanobiochar, sonication and centrifugation techniques were applied. The yield obtained was 27.5% for biochar and 0.9% for nanobiochar. Nanobiochar analysis through Fourier-Transform Spectrometer (FTIR), X-ray Power Diffraction (XRD) and scanning electron microscopy (SEM) suggested its crystalline nature having minerals rich in silicon, with a cracked and disintegrated carbon structure due to high temperature and processing treatments. Removal of dyes by nanobiochar was evaluated by changing different physical parameters i.e., nanobiochar dose, pH, and temperature. Pseudo-first order model and pseudo-second order model were applied to studying the adsorption kinetics mechanism. Kinetics for adsorption of dyes followed the pseudo-second order model suggesting the removal of dyes by process of chemical sorption. High adsorption was found at a higher concentration of nanobiochar, high temperature, and neutral pH. Maximum elimination percentages of safranin, malachite green, and a mixture of dyes were obtained as 91.7%, 87.5%, and 85% respectively. We conclude that nanobiochar could be a solution for dye removal from aqueous media.

CO2 Hydrogenation to Gasoline and Aromatics: Mechanistic and Predictive Insights from DFT, DRIFTS and Machine Learning.

The emission of CO2 from fossil fuels is the largest driver of global climate change. To realize the target of a carbon-neutrality by 2050, CO2 capture and utilization is crucial. The efficient conversion of CO2 to C5+ gasoline and aromatics remains elusive mainly due to CO2 thermodynamic stability and the high energy barrier of the C-C coupling step. Herein, advances in mechanistic understanding via Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), density functional theory (DFT), and microkinetic modeling are discussed. It further emphasizes the power of machine learning (ML) to accelerate the search for optimal catalysts. A significant effort has been invested into this field of research with volumes of experimental and characterization data, this study discusses how they can be used as input features for machine learning prediction in a bid to better understand catalytic properties capable of accelerating breakthroughs in the process.

Excellent low-temperature activity for oxidation of benzene serials VOCs over hollow Pt/CoMn2O4 sub-nanosphere: Synergistic effect between Pt and CoMn2O4 on improving oxygen activation

Constructing the interfacial active sites between noble metals and oxides is an effective way to enhancing the catalytic performance of noble metal-supported catalysts. Meanwhile, ultra-low dosage of the noble metal Pt but obtaining favorable catalytic activity is still major challenge to prepare noble metal-supported catalysts. Herein, the active Pt-CoMn2O4 interface with strong metal-support interaction (SMSI) is designed by loading ultra-low Pt content (0.12 wt%) on hollow structured CoMn2O4 sub-nanosphere (Pt/CoMn2O4). Compared with the reference MnOx, CoMn2O4 and Pt/MnOx, Pt/CoMn2O4 shows excellent catalytic activity even in presence of H2O, which is capable of completely converting toluene, ethylbenzene and o-xylene at 163, 207 and 218 °C, respectively. Various characterizations and density functional theory (DFT) calculations are performed to reveal the role of CoMn2O4 and specify the synergistic effect between Pt and CoMn2O4 on surface properties and catalytic performance. Intriguingly, in situ-designed temperature-programmed techniques and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy clarify the substitution of Co in CoMn2O4 enhances oxygen mobility, and the interface of Pt and support is the active sites for gaseous oxygen activation can also be confirmed by DFT calculation results. This SMSI is prone to promote the supplement of active oxygen species that is essential for excellent low-temperature catalytic oxidation performance. This study provides a new insight into the design of high-performance noble metal catalysts, and the understanding of textural structure, active species, synergistic effect, and mechanisms of catalytic systems.

High-performance CO2 Capture from Air by Harnessing the Power of CaO- and Superbase Ionic Liquid-Engineered Sorbents.

Direct air capture (DAC) of CO2 by solid porous materials represents an attractive "negative emission" technology. However, state-of-the-art sorbents based on supported amines still suffer from unsolved high energy consumption and stability issues. Herein, taking clues from the CO2 interaction with superbase-derived ionic liquids (SILs), high-performance and tunable sorbents in DAC of CO2 was developed by harnessing the power of CaO- and SIL-engineered sorbents. Deploying mesoporous silica as the substrate, a thin CaO layer was first introduced to consume the surface-OH groups, and then active sites with different basicities (e.g., triazolate and imidazolate) were introduced as a uniformly distributed thin layer. The as-obtained sorbents displayed high CO2 uptake capacity via volumetric (at 0.4 mbar) and breakthrough test (400 ppm CO2 source), rapid interaction kinetics, facile CO2 releasing, and stable sorption/desorption cycles. Operando Diffuse Reflectance Infrared Fourier Transformation Spectroscopy (DRIFTS) analysis under simulated air atmosphere and solid-state Nuclear Magnetic Resonance (NMR) under 13CO2 atmosphere demonstrated the critical roles of the SIL species in low-concentration CO2 capture.The fundamental insights obtained in this work provide guidance on the development of high-performance sorbents in DAC of CO2 by leveraging the combined advantages of porous solid scaffolds and the unique features of CO2-philic ILs.

Benzanthrone sulfides: synthesis, solvatochromism characterization and analysis of experimental photophysical parameters and theoretical calculations

In this paper the synthesis, characterization, and photophysical properties of benzanthrone-derived sulfides are discussed. The compounds were synthesized using a practical method of nucleophilic aromatic substitution reactions of 3-bromobenzanthrone with thiols. Structural characterization was conducted using nuclear magnetic resonance (NMR) and Fourier-transform (FTIR) spectroscopy and high-resolution mass spectrometry, confirming the chemical structures. The crystal structure of a compound was determined via X-ray diffraction, revealing π-π stacking interactions and intermolecular hydrogen bonding. Photophysical analysis showed solvatochromic effects (emission of light upon excitation from 507 nm in benzene to 591 nm in ethanol) and attributed fluorescence to intramolecular charge transfer. Computational analysis using DFT calculations provided further insights into the compounds' properties, including excited state energies and the potential for efficient intersystem crossing. Overall, the research provides a comprehensive understanding of the newly synthesized benzanthrone alkyl and aryl sulfides as well as a phenylselanyl derivative. The photophysical properties, charge transfer characteristics observed in the compounds and the solvatochromic effects exhibited by the compounds suggest their potential to be utilized for developing sensors for detecting environmental changes, chemical substances or biological targets.