High Purity Chemicals Research Articles

Solid Electrolytes for Low-Temperature Carbon Dioxide Valorization: A Review.

One of the most promising approaches to address the global challenge of climate change is electrochemical carbon capture and utilization. Solid electrolytes can play a crucial role in establishing a chemical-free pathway for the electrochemical capture of CO2. Furthermore, they can be applied in electrocatalytic CO2 reduction reactions (CO2RR) to increase carbon utilization, produce high-purity liquid chemicals, and advance hybrid electro-biosystems. This review article begins by covering the fundamentals and processes of electrochemical CO2 capture, emphasizing the advantages of utilizing solid electrolytes. Additionally, it highlights recent advancements in the use of the solid polymer electrolyte or solid electrolyte layer for the CO2RR with multiple functions. The review also explores avenues for future research to fully harness the potential of solid electrolytes, including the integration of CO2 capture and the CO2RR and performance assessment under realistic conditions. Finally, this review discusses future opportunities and challenges, aiming to contribute to the establishment of a green and sustainable society through electrochemical CO2 valorization.

Directional Electrosynthesis of Adipic Acid and Cyclohexanone by Controlling the Active Sites on NiOOH.

Dicarboxylic acids and cyclic ketones, such as adipic acid (AA) and cyclohexanone (CHN), are essential compounds for the chemical industry. Although their production by electrosynthesis using electricity is considered one of the most promising strategies, the application of such processes has been hampered by a lack of efficient catalysts as well as a lack of understanding of the mechanism. Herein, a series of monolithic msig/ea-NiOOH-Ni(OH)2/NF were prepared by means of self-dissolution of metal matrix components, interface growth, and electrochemical activation (denoted as msig/ea). The as-synthesized catalysts have three-dimensional cuboid-like structures formed by interconnecting nanosheets composed of NiOOH. By theoretically guided regulation of the amounts of Ni3+ and oxygen vacancies (OV), a 96.5% yield of CHN from cyclohexanol (CHA) dehydrogenation and a 93.6% yield of AA from CHN oxidation were achieved. A combined experimental and theoretical study demonstrates that CHA dehydrogenation and CHN oxidation were promoted by the formation of Ni3+ and the peroxide species (*OOH) on OV. This work provides a promising approach for directional electrosynthesis of high-purity chemicals with in-depth mechanistic insights.

Entropy Confinement Promotes Hydrogenolysis Activity for Polyethylene Upcycling.

Chemical upcycling that catalyzes waste plastics back to high-purity chemicals holds great promise in end-of-life plastics valorization. One of the main challenges in this process is the thermodynamic limitations imposed by the high intrinsic entropy of polymer chains, which makes their adsorption on catalysts unfavorable and the transition state unstable. Here, we overcome this challenge by inducing the catalytic reaction inside mesoporous channels, which possess a strong confined ability to polymer chains, allowing for stabilizing transition state. This approach involves the synthesis of p-Ru/SBA catalysts, in which Ru nanoparticles are uniformly distributed within the channels of an SBA-15 support, using a precise-impregnation method. The unique design of the p-Ru/SBA catalyst has demonstrated significant improvements in catalytic performance for the conversion of polyethylene into high-valued liquid fuels, particularly diesel. The catalyst achieved a high solid conversion rate of 1106 g·gRu-1·h-1 at 230 °C. Comparatively, this catalytic activity is 4.9 times higher than that of a control catalyst, Ru/SiO2, and 14.0 times higher than that of a commercial catalyst, Ru/C, at 240 °C. This remarkable catalytic activity opens up immense opportunities for the chemical upcycling of waste plastics.

Designing and significantly improved TeO2-based glass system for nuclear engineering applications: Radiation shielding performance and optical transparency

The radiation (beta particles (β), protons (1H), α-particles (He2+), carbon ions (C6+), fast neutrons (FN), and thermal neutrons (TN)) absorption parameters of 75TeO2–10MoO3–10BaO–(5-x)Sm2O3–xBi2O3 glass system were evaluated and presented along with their optical parameters in this study. The parameters were analyzed with the objective of evaluating the role of Sm and Bi atoms in altering the optical and radiation characteristics of the glass system. Starting with high-purity chemicals, namely BaCO3, Bi2O3, MoO3, TeO2, and Sm2O3, and following the melt-and-quench procedure, 75TeO2–10MoO3–10BaO–(5-x)Sm2O3–xBi2O3 glasses were prepared as TeMoBa-Sm/Bi1, TeMoBa-Sm/Bi2, TeMoBa-Sm/Bi3, TeMoBa-Sm/Bi4, and TeMoBa-Sm/Bi5 for Bi2O3 molar concentration of 0, 2, 4, 4.5, and 5 mol %, respectively. The optical parameters were computed theoretically from measured absorption spectra. The stopping powers and ranges of β-particles, protons, and α-particles were estimated using the ESTAR, PSTAR, and ASTAR software, respectively, while the SRIM code was used to compute for heavy carbon ions. In addition, the cross-sections of fast (FN) and thermal (TN) neutrons were computed using the standard expressions. There was a positive correlation between Bi2O3 content and the molar volume of the glasses. The refractive indices vary slightly between 2.53 and 2.56. The molar refractivity (Rm) values for TeMoBa-Sm/Bi1, TeMoBa-Sm/Bi2, TeMoBa-Sm/Bi3, TeMoBa-Sm/Bi4, and TeMoBa-Sm/Bi5 are 19.769 cm3/mol, 19.730 cm3/mol, 19.689 cm3/mol, 19.656 cm3/mol, and 19.754 cm3/mol, respectively. The values of Sp for proton are highest at 0.09 MeV with values of 284.047, 281.041, 278.135, 277.434 and 276.633 MeV cm2/g for TeMoBa-Sm/Bi1, TeMoBa-Sm/Bi2, TeMoBa-Sm/Bi3, TeMoBa-Sm/Bi4, and TeMoBa-Sm/Bi5, respectively. The Bi2O3 content thus improved the CR shielding ability of the glass system slightly. The optimum Bi2O3 concentration for FN shielding is 4 mol %. In addition, Bi2O3 compromised the TN absorption ability of the TeMoBa-Sm/Bi glass system.

Thermoelectric properties of pseudobrookite-based ceramics prepared from natural Fe-Ti-rich heavy mineral sand concentrate

Pseudobrookites (Fe2TiO5-FeTi2O5) are promising candidates for high-temperature oxide thermoelectrics. In this work, we used natural Fe-Ti-rich heavy mineral sand (HMS) as an abundant and environmentally friendly raw material for the preparation of pseudobrookite-based ceramics. The main components of the initial powder were ilmenite (FeTiO3) and pseudorutile (Fe2Ti3O9) with various degrees of alteration. Pre-oxidation of the as-received powder was used for modification of the Fe2+:Fe3+ ratio and exsolution of rutile. The starting powders were densified by conventional sintering (CS; 1200 °C, 5 h, pressureless) and spark plasma sintering (SPS; 1100 °C, 5 min, 150 MPs) in argon. The thermoelectric properties of the sintered compacts depend mainly on the Fe:Ti ratio, the Fe2+:Fe3+ ratio, and the fraction and distribution of rutile in the microstructures. The samples exhibit comparable properties as the pseudobrookite-based ceramics prepared from high-purity chemicals indicating that, with some further optimization, natural Fe-Ti-rich HMS are an interesting alternative for the preparation of pseudobrookite-based ceramics for thermoelectric applications.

Optical properties and radiation shielding performance of tellurite glassy composites: Role of rare earth oxides

In this research, the synthesis, optical parameters, and radiation absorption quantities of 50TeO2–15Na2O—(20-x)PbO—15ZnO—xEu2O3 glasses were reported. The glasses were prepared by the well-known melting and quenching method using high purity chemicals. The glasses were coded as TPEu-0, TPEu-1, TPEu-2, and TPEu-3 for glasses containing 0, 1, 2, and 3 mol% of Eu2O3, respectively. The density of the glasses was determined by the Archimedes method. The optical parameters of the glasses, such as the refractive index n, molar refractivity Rm, molar polarizability αm, reflection loss RL, optical transmission T, metallization criterion M, static dielectric constant εstatic, and optical dielectric constant εoptical were estimated by theoretical methods. The stopping powers and range of electrons, protons, α-particles, and carbon ions in the TPEu-X glasses for particle kinetic energies between 15 keV and 15 MeV were computed using the ESTAR, PSTAR, ASTAR, and STRIM software. In addition, the fast neutron (FN) removal cross section (FNRCS), thermal neutron (TN), and total cross-section (σtot) for the prepared glasses were evaluated theoretically using established models. The estimated optical parameters showed strong relationship with the chemical content of the glasses. Glass density and molar volume increased as Eu2O3 content increased. The Rm, αm, RL, εstatic, and εoptical vary from 16.24 to 17.20 cm3/mol, 6.44 × 10−24 cm3‒17.20 × 10−24 cm3, 0.17–0.19, 5.71–6.55, and 4.71–5.55 respectively, with TPEu-0 and TPEu-1 having the maximum and minimum values, respectively. Generally, the increase in Eu2O3 concentration increased the charged radiation shielding ability of the glasses. The increment in the Eu2O3 content of the glasses brought about an improvement in the thermal and fast neutron absorption probabilities of the glasses.

A novel robust phosphate-functionalized metal–organic framework for deep desulfurization at wide temperature

The need to decrease environmental pollution, reduce energy consumption and produce high-purity chemicals has become an increasingly important driving force for sulfur dioxide (SO2) capture. The efficient capture of low concentrations of SO2, a highly corrosive acid gas that is not typically present in high concentrations in industrial settings, is a major challenge. Herein, a novel phosphate-functionalized metal–organic framework, ZU-801, is designed with precisely controlled pore sizes and chemical environment to achieve excellent adsorption capacity for SO2 (1.44 mmol g−1 at 0.002 bar, 2.00 mmol g−1 at 0.01 bar) and high IAST selectivities for SO2/CO2 (145), which provides great potential for selective capture of SO2. ZU-801 shows excellent stability to air, water, SO2, strong acid and strong base solutions, and it is thermally stable up to 733 K. Additionally, ZU-801 exhibits outstanding separation ability in removing SO2 from SO2/CO2 mixtures at temperature as high as 383 K or in humid environments. This work demonstrates the potential of designing ion-functionalized ultramicroporous materials with tailored pore sizes and porous chemical environments for efficient capture and separation of SO2 and sheds light on designing stable high-performance materials that operate at high temperatures.

Photomodulation on Active Sites of Adsorbents: Controllable Adsorption Processes with Improved Efficiency.

Adsorption is a widely applied technique in producing high-purity chemicals with advantages of low energy consumption, high selectivity, and mild operating conditions. However, traditional adsorbents have inflexible properties and suffer from the trade-off between selective adsorption and efficient desorption. Recently, the emerging photoresponsive adsorbents have provided new avenues for adsorption techniques. Active sites of photoresponsive adsorbents can be regulated through steric hindrance or tunable adsorbent-adsorbate interactions. Therefore, variation in adsorptive capacity is able to readily achieve through photomodulation, and the corresponding adsorption/desorption cycles are energy-saving. This concept mainly summarizes recent efforts on the fabrication and application of photoresponsive adsorbents with tunable active sites. Also, the future opportunities and critical challenges of photoregulation on adsorptive sites are presented.

Entegris to expand US electronic chemicals

The specialty chemical maker Entegris is planning a $50 million expansion in North America for high-purity chemicals used in semiconductor and electronics manufacturing. The investment will boost production and purification capacity over the next 2 years at the firm’s plants in Pueblo, Colorado, and Hollister, California. In a press release, the firm says it anticipates strong demand growth in the US and the European Union as a result of new government incentives for the semiconductor industry.

Preparation of catalyst from natural montmorillonite mineral and its application in the synthesis of carbon nanosphere

In developed countries, nanoparticles derived from natural minerals and high-purity chemicals both are widely studied, while in developing countries like Mongolia, the natural minerals-based nanoparticles have more interest because of the low production cost and applicability of domestic natural minerals for their production. For the synthesis of natural mineral-based nanomaterials, it is important first to define the chemical composition and physical structure of local minerals and their possible processing route. We employed an environmentally friendly alkaline leaching procedure to recover silica from the clay mineral at 90°C for 24 hours. We applied an organic surfactant (CTAB) and a simple coprecipitation approach to form iron-doped silica nanoparticles. Consequently, we used iron-doped silica nanoparticles as a substrate and catalyst for the synthesis of carbon nanosphere at 750 °C for 1 hour in an argon and acetylene gas atmosphere. As a result, vast quantities of superhydrophobic carbon nanospheres (CNS) were obtained. The physicochemical properties of nanosilica substrate, non-functionalized carbon nanosphere, and functionalized carbon nanosphere (CNS) samples were characterized using XRD, XRF, SEM, EDS, TEM, and FTIR spectrometer. Iron-doped mineral-derived nanosilica particles demonstrated high catalytic efficiency and the potential to produce a large amount of value-added carbon nanospheres. Superhydrophobic CNS can be used in a variety of applications, particularly drug delivery; however, to use CNS in both aqueous and non-aqueous media, the superhydrophobic properties of CNS can be modified using different oxidizers. The changes in hydrophobicity of the CNS were examined and suggested possible oxidizing agents.

Highly selective conversion of tetrabromobisphenol A epoxy resin waste to high-purity phenolic chemicals by subcritical water-CuO process

Tetrabromobisphenol A epoxy resin (TBBPA-ER) is the most important nonmetallic composition of waste printed circuit boards (PCBs). Currently, the TBBPA-ER waste is mainly sent to incineration or landfills. The great obstacle of the recovery of the TBBPA-ER waste is the low value-added products obtained by existing technologies. In this study, a novel resource conversion strategy was developed to produce high-purity phenolic chemicals from the TBBPA-ER waste by subcritical water-CuO (SubCW-CuO) process. The high selectivity of the SubCW-CuO process for the recovered products from the TBBPA-ER waste could be attributed to the regulating effect of CuO. The CuO could preferentially trigger the rupture of C-O and C-Ph bonds in the TBBPA-ER chain, resulting in the producing of high-purity phenol (91.47 %) at 300 °C. The reaction between phenol and methyl radical (derived from β-scission of ternary carbon chain groups in the TBBPA-ER waste) resulted in the recovery of high-purity p-cresol (90.30 %) at 350 °C. The optimal conditions of the SubCW-CuO process were solid-liquid ratio of 1:30 g/mL, M(TBBPA-ER):M(CuO) ratio of 10:1 g/g, and 60 min. The conversion ratio of the TBBPA-ER waste could reach 70 % under the optimal conditions. Approximately 3 % of the bromine was transferred into the oil phase products after the SubCW-CuO process at 250 °C, while no organic bromine could be found in the oil phase products at 300 and 350 °C. More than 70 % of the bromine was fixed in the solid residue after the SubCW-CuO process at 300 and 350 °C. The bromine contained in the solid residue mainly existed in the form of CuBr and the Cu species had efficient capture ability for the bromine released from the molecular chain of the TBBPA-ER. It is believed that the SubCW-CuO process developed in this study is a promising alternative technology for the high-efficiency resource conversion of the TBBPA-ER waste.

ICP-MS: Key Steps to Control Contamination and Achieve Low Detection Limits

Inductively coupled plasma mass spectrometry (ICP-MS) instruments can perform low-level elemental analysis in a wide range of sample types, from high-purity chemicals to high matrix digests. But achieving consistently low detection limits requires good control of elemental contamination, as well as spectral interferences. A clean working area, careful selection of reagents, and good sample handling techniques are key to successful trace and ultratrace elemental analysis. In this article, we provide five practical tips for controlling contaminants and minimizing detection limits.

Towards sustainable production of minerals and chemicals through seawater brine treatment using Eutectic freeze crystallization and Electrodialysis with bipolar membranes

European policy encourages the adoption of sustainable systems that promote the efficient use and recovery of minerals and chemicals. In this respect, desalination brines do contain a dramatic amount of valuable minerals and can be valorized through appropriate treatments rather than releasing them into the environment. This paper proposes an innovative brine recovery system for obtaining high purity chemicals through the integration of Eutectic Freeze Crystallization (EFC) and Electrodialysis with Bipolar Membrane (EDBM) technologies. Two separate laboratory-scale experimental campaigns were carried out to validate the potential integration of the two processes. Mirabilite (Na2SO4∙10H2O) has been recovered with a purity of 99.9% using the EFC, and a feed rich in NaCl with low impurities has been further processed in an EDBM unit. EDBM tests with feed solutions simulating EFC effluents have shown that it is possible to produce acidic and basic solutions with high purity (>99%), despite the presence of impurities in the feed. Interestingly, the low EDBM specific consumptions of 0.9–1.1 kWh kg−1NaOH at 100 A m−2 and 1.3–1.6 kWh kg−1NaOH at 300 A m−2 were comparable with and without impurities. In the context of the circular economy strategy promoted by the EU-H2020 Water Mining project, the current study demonstrates that this integrated system effectively minimizes waste, promoting sustainability while providing a potential economic return.

Structural, optical and Judd-Offelt intensity parameters of samarium doped with zinc tellurite glasses

ObjectiveThe current challenges in materials science and technology is to modify the optical response of rare-earth-doped inorganic glasses for optical applications. The main objectives of the present study are to identify the effect of samarium oxide concentration on the linear optical properties of the zinc tellurite glass system and to use the Judd–Ofelt analysis to study the compositional dependence of the optical properties of the synthesized glasses. MehodologyZinc tellurite glasses [(TeO2)0.7 (ZnO) 0.3]1−x [Sm2O3NPs] x, with x = 0.01, 0.02, 0.03, 0.04 and 0.05 molar fraction are prepared by melt quenching technique. The glass samples were produced by employing high-purity analytical chemicals of TeO2 (Alfa Aesar 99.99 per cent), ZnO (Alfa Aesar 99.99 per cent) and Sm2O3 NPs (Alfa Aesar 99.99 per cent). The density of the glass samples was determined based on Archimedes principles with distilled water as an immersed liquid. The density measurement was taken at 10 different times and the average value was recorded. ResultsDensimeter, Fourier transform infrared (FTIR) and X-ray diffraction (XRD) were used to study the physical and structural properties. The density and molar volume increases from 5.10 to 5.32 g/cm3 and 27.06–27.54 cm3/mol with an increase in Sm2O3 NPs concentrations. The XRD revealed that the glasses are amorphous. FTIR spectrum reflects the TeO4 structural unit stretching mode. The UV-Vis absorption spectra have seven absorption peaks from the ground state 6H5/2 to 4F7/2, 4I9/2, 6F11/2, 6F9/2, 6F7/2,6F5/2, and 6F3/2 excited energy levels of Sm3+ NPs. The emission spectra under 404 nm wavelength comprised of four bands at 566 nm, 604 nm, 647 nm, and 710 nm represented as 4G5/2→6H5/2, 6H7/2, 6H9/2, and 6H11/2 transitions. The presence of Sm2O3 NPs was confirmed by high-resolution electron microscopy transmission (HR-TEM) with a particle size of 72.43 nm. Judd-Offelt parameters (Ω2= 4.94, Ω4=4.38 and Ω6=3.38) were obtained from the least square fitting and the results revealed that the glasses have potential for laser application.

Natural ore molybdenite as a high-capacity and cheap anode material for advanced lithium-ion capacitors

Hybrid lithium-ion capacitors (LICs) receive special interests because they work by combining the merits of high-capacity lithium-ion batteries and high-rate capacitors in a Li salt containing electrolyte, so as to bridge the gap between the two devices. One of main challenges for LICs is to develop inexpensive and superior anode materials at high rates. In this work, natural molybdenite was utilized as precursor to achieve the scalable production of cheap MoS2/carbon composites. This molybdenite-derived MoS2/carbon electrode can not only exhibit excellent Li+-storage performances including ultrahigh specific capacity (1427 mAh g–1 after 1000 cycles at 1 A g–1) and rate capability (554 mAh g–1 at 10 A g–1), but also possess four-times higher tap density than that of commercial graphite. By employing MoS2/carbon as the anode and activated carbon as the cathode, the as-assembled LIC device delivers both high energy//high power density and long cycle lifespan. Furthermore, the price is nearly 200 orders of magnitude lower than the traditional high-purity chemicals, which can be easily scaled up to achieve high-throughput production.

Firms invest in high-purity chemicals

Firms invest in high-purity chemicals

Sumitomo, Solvay invest in high-purity chemicals

Sumitomo, Solvay invest in high-purity chemicals

Dielectric materials for enhancement of the sensitivity of electron paramagnetic resonance spectroscopy

Impact of the starting reagents on the dielectric properties of ZnO-doped materials based on BaTi4O9 has been investigated. Value of the electrical quality (Q) of the synthesized ceramics has significantly depended on the purity of the starting reagents (TiO2) and varied in the range of 1700–5300 at 10 GHz. Ceramics with the high values of the dielectric constant ε ≈ 35 and Q ≈ 5300 has been obtained using the high-purity chemicals (purity of TiO2 – 99,998%). Dielectric resonators have been produced based on the synthesized ceramics and their application has allowed enhancing the sensitivity of EPR measurements according to the theoretical calculations. On the example of the investigations of MnCl2 salt it has been demonstrated experimentally that the application of the additional dielectric resonator has allowed enhancing the intensity of EPR signal of Mn2+ ions from 5.5 times (with Q = 1700) to 11 times (with Q = 5300).

Purification Method for Achieving Low Trace Metals in Ultra-High Purity Chemicals

The high purity requirements of materials used in semiconductor manufacturing are being pushed to unprecedented levels as demand for reliability in computer processors over increasingly longer lifetimes continues to rise. The production of these high purity chemicals requires new purification methods and technologies where the metal concentrations of low parts per billion (ppb) were effectively reduced to low parts per trillion (ppt). The new approach discussed in this paper would present a method for dividing the fluid through micro-channels that form tortuous pathways. These micro-channels allow for further dividing and converging of the fluid thereby presenting the metal species to the purifying surfaces throughout the porous matrix. The ion exchange capability was a function of the concentration and the presence of the species in the solution. Two ion exchange chemistries of strong acid and chelating were made into these structures and their purification performances were assessed and compared in terms of removal efficiencies. Furthermore, these two chemistries were evaluated in series to demonstrate the overall synergistic purification capabilities.

Graphite furnace atomic absorption spectrometric studies for the quantification of trace and ultratrace impurities in the semiconductor grade organic chemicals such as triethylborate, tetraethylorthosilicate and trimethylphosphate

The paper describes the direct determination of impurities by graphite furnace atomic absorption spectrometry (GF AAS) in high (7 N, i.e. 99.99999%) purity organic compounds used as precursors for the deposition of dielectric films by chemical vapour deposition (CVD). The impurity analysis is required to assess the suitability of the compounds that include triethyl borate (TEB), tetraethyl orthosilicate (TEOS) and trimethyl phosphate (TMPO), used as precursors for the deposition of compositionally good quality films. Such features as high sensitivity and limits of detection of GFAAS are exploited for the direct determination of twenty elements (Ag, Al, Bi, Ca, Cd, Cr, Co, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sn, Sb, Zn) in μg L−1 levels in the three compounds. The analysis was preceded by a comprehensive study on the quantitative recovery of spiked elements using clean room procedures. Specially designed sample holders made of polytetrafluoroethylene (PTFE) were used for the analysis. The routinely used polystyrene sample holders are attacked by these chemicals and are thus rendered unsuitable for analysis. GFAAS operating parameters such as drying, pyrolysis and atomisation temperatures were optimized for each analyte in each organic sample for the removal of the matrix effects on the analyte and for quantitative recovery of the analytes. A fourth drying step was introduced in the furnace program. The accuracy of the method has been established by spike recovery tests in the absence of certified reference materials for high purity chemicals. The method is free from any interference and has a precision of <10%. Studies on the effect of polypropylene (PP) and perfluoroalkhoxy (PFA) storage containers on the impurities of these chemicals were performed and the results were discussed. The method can be effectively utilized for the quality control and quality assurance of these important class of chemicals used extensively in semiconductor industry.