Single crystal structure, vibrational spectroscopy, gas sorption and antimicrobial properties of a new inorganic acidic diphosphates material (NH4)2Mg(H2P2O7)2•2H2O

Efficient crystal structure materials as reactive sorbent for the CO2 and CH4 adsorption and storage

The efficient dirubidium cobalt bis(dihydrogendiphosphate) dihydrate compound is successfully synthesized in a solution and used as a reactive sorbent for the CO2 and CH4 gases adsorption and storage. A crystal of this Rb2Co(H2P2O7)2·2H2O compound has been isolated and characterized by single X-ray diffraction analysis and was found to crystallize in the triclinic system ( P 1 ¯ ) with the cell parameters (Å): 6.980(1), 7.370(1), 7.816(1), 81.74(1), 70.35(1), 86.34(1); V = 374.68(9) Å3, Z = 2. The crystal-packing consists of a three-dimensional framework made upon corners and edges sharing of [RbO7], [H2P2O7] and [CoO6] entities, furthermore linked by a network of H-bonds. The UV-Vis spectroscopy revealed usual transitions between the ground state 4T1g and the upper levels 4T2g, 4A2g and 4T1g (P). Moreover, the CO2 and CH4 gases sorption measurements were successfully performed at two different temperatures (25 and 45 °C) and various pressures ranging from vacuum to 50 bar. Our results show that rate of CO2 and CH4 capturing was 3.10 mmol/g and 2.35 mmol/g at temperature 25 °C and pressure 50 bar, respectively. This compound showed a clear potential for CO2/CH4 adsorption and storage thereby paving the way towards its exploration and adaptation for capturing and collecting carbon dioxide and greenhouse gases from the air, and their conversion into hydrocarbon fuels using existing mature technologies. We have also conducted density functional theory calculations to study the CO2 and CH4 adsorption properties of Rb2Co(H2P2O7)2·2H2O. The simulation results show enhanced adsorption of both types of molecules on the surface of the material.

Emerging trends in direct air capture of CO2: a review of technology options targeting net-zero emissions

The increasing concentration of carbon dioxide (CO2) in the atmosphere has compelled researchers and policymakers to seek urgent solutions to address the current global climate change challenges. In order to keep the global mean temperature at approximately 1.5 °C above the preindustrial era, the world needs increased deployment of negative emission technologies. Among all the negative emissions technologies reported, direct air capture (DAC) is positioned to deliver the needed CO2 removal in the atmosphere. DAC technology is independent of the emissions origin, and the capture machine can be located close to the storage or utilization sites or in a location where renewable energy is abundant or where the price of energy is low-cost. Notwithstanding these inherent qualities, DAC technology still has a few drawbacks that need to be addressed before the technology can be widely deployed. As a result, this review focuses on emerging trends in direct air capture (DAC) of CO2, the main drivers of DAC systems, and the required development for commercialization. The main findings point to undeniable facts that DAC's overall system energy requirement is high, and it is the main bottleneck in DAC commercialization.

Fluorescent Zn(II)-Based Metal-Organic Framework: Interaction with Organic Solvents and CO2 and Methane Capture

Adsorption of carbon dioxide (CO₂), as well as many other kinds of small molecules, is of importance for industrial and sensing applications. Metal-organic framework (MOF)-based adsorbents are spotlighted for such applications. An essential for MOF adsorbent application is a simple and easy fabrication process, preferably from a cheap, sustainable, and environmentally friendly ligand. Herein, we fabricated a novel structural, thermally stable MOF with fluorescence properties, namely Zn [5-oxo-2,3-dihydro-5H-[1,3]-thiazolo [3,2-a]pyridine-3,7-dicarboxylic acid (TPDCA)] • dimethylformamide (DMF) •0.25 H₂O (coded as QUF-001 MOF), in solvothermal conditions by using zinc nitrate as a source of metal ion and TPDCA as a ligand easy accessible from citric acid and cysteine. Single crystal X-ray diffraction analysis and microscopic examination revealed the two-dimensional character of the formed MOF. Upon treatment of QUF-001 with organic solvents (such as methanol, isopropanol, chloroform, dimethylformamide, tetrahydrofuran, hexane), interactions were observed and changes in fluorescence maxima as well as in the powder diffraction patterns were noticed, indicating the inclusion and intercalation of the solvents into the interlamellar space of the crystal structure of QUF-001. Furthermore, CO₂ and CH₄ molecule sorption properties for QUF-001 reached up to 1.6 mmol/g and 8.1 mmol/g, respectively, at 298 K and a pressure of 50 bars.

A novel organometallic magnesium complexes with aggregation induced emission properties: synthesis, characterization, and fluorescent fibres applications

In this work, a novel organomagnesium complex with outstanding aggregation induced emission (AIE) properties was synthesized using dibenzoylmethane (DBM) as the ligand. The structure of the complex was confirmed to be one magnesium ion coordinated to the diones groups of two DBM molecules, and the magnesium ion adopted a distorted octahedrally geometry. The obvious emission was found for Mg(DBM) 2 powder and not in the solution, which was the first reported organomagnesium complex with AIE property. The properties of complexes were investigated by UV-vis absorption and fluorescence emission spectroscopy, cyclic voltammetry and density functional theory calculations. Moreover, the Mg(DBM) 2 solution dispersed in fifilter paper was nearly colorless, which could be made into a convenient anti-counterfeiting and encryption tool. Mg(DBM) 2 /alginate fibres were prepared by wet-spinning process and further processed into paper, which could be used in the fields of sensor, anti-counterfeiting and encryption. Sweat contains a wealth of chemical information that could potentially indicate the body's deeper biomolecular state. The prepared fluorescent fibres were used to detect sweat due to its non-toxic, low-cost efficient and fast response to analytes.

State of the Art in Separation Processes for Alternative Working Fluids in Clean and Efficient Power Generation

Gas turbines must now comply with much stricter emission control regulations. In fact, to combat the greenhouse effect, regulatory authorities have drastically reduced allowable emission levels. For example, in less than 12 years, the United States’ Clean Air Act issued the New Source Performance Standards (NSPS), which tightened the NOx emission margin of natural gas combustion (from 75 ppm to 10 ppm). On the other hand, despite those efforts, the high demand for energy produced by fossil-fueled gas turbines in power plants has resulted in dramatic increases in anthropogenic CO2 and NOx emitted by gas combustors. Most systems responsible for these undesirable emissions are directly linked to power generation, with gas turbines playing a pivotal role. Yet, gas turbines are still widely used in power plants and will continue to meet the growing demand. Therefore, sequestration and separation techniques such as Carbon Capture and Storage (CCS) and Air Separation Units (ASU) are essential to reduce CO2 and NOx emissions while allowing large amounts of power to be generated from these systems. This paper provides an in-depth examination of the current state of the art in alternative working fluids utilized in the power generation industry (i.e., gas turbines, combustion). In addition, this paper highlights the recent contribution of integrating separation techniques, such as air separation, steam methane reforming, and water-gas shifting, to the power generation industry to facilitate a continuous and adequate supply of alternative working fluids.