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He J, Yuan M, Li B, Zhang R. Research on the Optimization for Acidification Modification Scheme Considering Coal's Wettability Based on the AHP-TOPSIS Method. ACS OMEGA 2023; 8:32667-32676. [PMID: 37720767 PMCID: PMC10500681 DOI: 10.1021/acsomega.3c03428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/09/2023] [Indexed: 09/19/2023]
Abstract
Acidification technology is an important measure for enhancing the extraction of coalbed methane from seams with low permeability and abundant minerals, and the acidification scheme is the key to the success of acidification treatment. To determine the optimal acidification modification scheme, an improved AHP-TOPSIS method is proposed to decide on the optimal conditions for wettability modification. This method constructs an evaluation index system, taking the wettability of coal as the target layer and the pro/hydrophobic functional groups in coal as the index layer. Meanwhile, it innovatively takes the adsorption energy of each functional group when absorbing a single water molecule as the basis for assigning weights to the evaluation indexes. Then, nine acidification modification schemes are evaluated and selected by the improved AHP-TOPSIS method based on the test results of different schemes to get the optimal one. The optimal scheme selected by the AHP-TOPSIS method is validated by water adsorption tests and isothermal adsorption tests. The results showed that the significance of each evaluation index is ranked as follows: aromatic structures > hydroxyl groups > aliphatic functional groups > oxygen-containing functional groups. The optimal acidification modification scheme is selected by the AHP-TOPSIS method with a HF concentration of 4% and a reaction time of 6 h. The ranking of acidification modification schemes obtained by the AHP-TOPSIS method is in high agreement with the ranking of water adsorption tests. When compared with raw coal, the coal samples treated with the optimal scheme have lower adsorption capacity for gas, which indicates that the aforementioned method could be used to evaluate and select the optimal acidification modification scheme, and the selected optimal scheme has the potential to increase the output of coalbed methane.
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Affiliation(s)
- Jimin He
- Mining
of College, Guizhou University, Guiyang 550025, Guizhou, China
| | - Mei Yuan
- Mining
of College, Guizhou University, Guiyang 550025, Guizhou, China
- Guizhou
Key Laboratory of Comprehensive Utilization of Non-metallic Mineral
Resources, Guiyang 550025, Guizhou, China
| | - Bobo Li
- Mining
of College, Guizhou University, Guiyang 550025, Guizhou, China
- Guizhou
Key Laboratory of Comprehensive Utilization of Non-metallic Mineral
Resources, Guiyang 550025, Guizhou, China
| | - Rui Zhang
- Mining
of College, Guizhou University, Guiyang 550025, Guizhou, China
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Fu S, Tan B, Cheng G, Wang H, Fang X, Li Z, Guo M, Zan X. Molecular model construction of Chifeng lignite and analysis of adsorption mechanism of O2 at low temperature. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.134613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zhao D, Liu X. Density Functional Calculation of H 2O/CO 2/CH 4 for Oxygen-Containing Functional Groups in Coal Molecules. ACS OMEGA 2022; 7:17330-17338. [PMID: 35647441 PMCID: PMC9134381 DOI: 10.1021/acsomega.2c01278] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 04/28/2022] [Indexed: 06/15/2023]
Abstract
To investigate the adsorption mechanism of H2O, CO2, and CH4 molecules on oxygen-containing functional groups (OFGs) in coal molecules, quantum chemical density functional theory (DFT) simulations were performed to study the partial density of states and Mulliken bond layout of H2O molecules bonded to different OFGs. The adsorption energy and Mulliken charge distribution of the H2O, CO2, and CH4 molecules for each OFG were determined. The results showed that H2O molecules form 2, 1, 1, and 1 hydrogen bonds with -COOH, -OH, -C=O, and -O-R groups, respectively. Double hydrogen bonds connected the H2O molecules to -COOH with the smallest adsorption distances and highest Mulliken bond layout values, resulting in the strongest bonding between the H2O molecules and -COOH. The most stable configuration for the adsorption of these molecules by the -OH group was when the O-H bond in the OFG served as a hydrogen bond donor and the O atom in the H2O molecule served as a hydrogen bond acceptor. The order of the bonding strength between the OFGs and H2O molecules was Ph-COOH > Ph-OH > Ph-C=O > Ph-O-R. The adsorption energy calculation results showed that H2O molecules have a higher adsorption stability than CO2 and CH4 molecules. Compared with the -OH, -C=O, and -O-R groups, the -COOH group had a higher adsorption capacity for H2O, CO2, and CH4 molecules. The adsorption stability of the CO2 molecules for each OFG was higher than that of the CH4 molecules. From the Mulliken charge layout, it was clear that after the adsorption of the H2O molecules onto the OFGs, the O atoms in the OFGs tend to gain electrons, while the H atoms involved in bonding with the H2O molecules tend to lose electrons. The formation of hydrogen bonds weakens the strength of the bonds in the H2O molecule and OFGs, and thus, the bond lengths were elongated.
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Affiliation(s)
- Dan Zhao
- College
of Safety Science and Engineering, Liaoning
Technical University, Fuxin 123000, China
- Key
Laboratory of Mine Power Disaster and Prevention of Ministry of Education, Huludao, 125105 Liaoning, China
| | - Xiaoqing Liu
- College
of Safety Science and Engineering, Liaoning
Technical University, Fuxin 123000, China
- Key
Laboratory of Mine Power Disaster and Prevention of Ministry of Education, Huludao, 125105 Liaoning, China
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Liu X, Bai Y, Chen S, Wu C, Gates ID, Huang T, Li W, Yang W, Gao Z, Yao J, Ding X. A descriptor for the structural stability of organic-inorganic hybrid perovskites based on binding mechanism in electronic structure. J Mol Model 2022; 28:80. [PMID: 35247076 DOI: 10.1007/s00894-022-05046-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 01/31/2022] [Indexed: 10/18/2022]
Abstract
The poor stability of organic-inorganic hybrid perovskites hinders its commercial application, which motivates a need for greater theoretical insight into its binding mechanism. To date, the binding mode of organic cation and anion inside organic-inorganic hybrid perovskites is still unclear and even contradictory. Therefore, in this work based on density functional theory (DFT), the binding mechanism between organic cation and anion was systematically investigated through electronic structure analysis including an examination of the electronic localization function (ELF), electron density difference (EDD), reduced density gradient (RDG), and energy decomposition analysis (EDA). The binding strength is mainly determined by Coulomb effect and orbital polarization. Based on the above analysis, a novel 2D linear regression descriptor that Eb = - 9.75Q2/R0 + 0.00053 V∙EHL - 6.11 with coefficient of determination R2 = 0.88 was proposed to evaluate the binding strength (the units for Q, R0, V, and EHL are |e|, Å, bohr3, and eV, respectively), revealing that larger Coulomb effect (Q2/R0), smaller volume of perovskite (V), and narrower energy difference (EHL) between the lowest unoccupied molecular orbital (LUMO) of organic cation and the highest occupied molecular orbital (HOMO) of anion correspond to the stronger binding strength, which guides the design of highly stable organic-inorganic hybrid perovskites.
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Affiliation(s)
- Xiaoshuo Liu
- Department of Power Engineering, School of Energy, Power, and Mechanical Engineering, North China Electric Power University, Baoding, 071000, China.,Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Yang Bai
- Department of Power Engineering, School of Energy, Power, and Mechanical Engineering, North China Electric Power University, Baoding, 071000, China
| | - Shengyi Chen
- Department of Power Engineering, School of Energy, Power, and Mechanical Engineering, North China Electric Power University, Baoding, 071000, China
| | - Chongchong Wu
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Ian D Gates
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Tianfang Huang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Wei Li
- School of Mathematics and Physics, North China Electric Power University, Beijing, 102206, China.,Institute of Clusters and Low Dimensional Nanomaterials, School of Mathematics and Physics, North China Electric Power University, Beijing, 102206, China
| | - Weijie Yang
- Department of Power Engineering, School of Energy, Power, and Mechanical Engineering, North China Electric Power University, Baoding, 071000, China
| | - Zhengyang Gao
- Department of Power Engineering, School of Energy, Power, and Mechanical Engineering, North China Electric Power University, Baoding, 071000, China.
| | - Jianxi Yao
- State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources, North China Electric Power University, Beijing, 102206, China. .,Beijing Key Laboratory of Energy Safety and Clean Utilization, North China Electric Power University, Beijing, 102206, China.
| | - Xunlei Ding
- School of Mathematics and Physics, North China Electric Power University, Beijing, 102206, China. .,Institute of Clusters and Low Dimensional Nanomaterials, School of Mathematics and Physics, North China Electric Power University, Beijing, 102206, China.
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Huo Y, Zhu H, He X, Fang S, Wang W. Quantum Chemistry Calculation Study on Chain Reaction Mechanisms and Thermodynamic Characteristics of Coal Spontaneous Combustion at Low Temperatures. ACS OMEGA 2021; 6:30841-30855. [PMID: 34805713 PMCID: PMC8600629 DOI: 10.1021/acsomega.1c05307] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 10/27/2021] [Indexed: 06/13/2023]
Abstract
The coal spontaneous combustion phenomenon seriously affects the safety production of coal mines. Aiming at the problem of complex coal molecular structure and incomplete reaction sequences at present, the mechanisms and thermodynamic parameters of coal spontaneous combustion chain reactions were explored by combining experimental detections and molecular simulations. First, the active groups on the surface of coal were obtained by Fourier transform infrared spectroscopy (FTIR), mainly including methyl (-CH3), methylene (-CH2), methyne (-CH), phenolic hydroxyl (-ArOH), alcohol hydroxyl (-ROH), carboxyl (-COOH), aldehyde (-CHO), and ether (-O-), and the coal molecular models containing functional groups and radicals were established. According to the charge density, electrostatic potential, and frontier orbital theories, the active sites and active bonds were obtained, and a series of reactions were given. The thermodynamic and structural parameters of each reaction were explored. In the chain initiation reaction stage, O2 chemisorption and the self-reaction of radicals play a leading role. In this stage, heat gradually accumulates and various radicals begin to generate, where the intramolecular hydrogen transfer reaction of a peroxide radical (-C-O-O·) can produce the key hydroxyl radical (-O·). In the chain propagation reaction stage, O2 and -O· continuously consume active sites to accelerate the reaction sequences and increase the temperature of coal, and index gases such as CO and CO2 generate, causing the chain cycle reactions to gradually form. The chain termination reaction stage is the formation of stable compounds such as ethers, esters, and quinones, which can inhibit the development of chain reactions. The results can further explain the reaction mechanism of coal spontaneous combustion and provide references for the development and utilization of chemical inhibitors.
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Chacón P, Hernández-Lima JG, Bazán-Jiménez A, García-Revilla MA. Modeling Adsorption and Optical Properties for the Design of CO 2 Photocatalytic Metal-Organic Frameworks. Molecules 2021; 26:3060. [PMID: 34065514 PMCID: PMC8161253 DOI: 10.3390/molecules26103060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/14/2021] [Accepted: 05/16/2021] [Indexed: 11/30/2022] Open
Abstract
Four Metal-Organic Frameworks (MOFs) were modeled (IRMOF-C-BF2, IRMOF-C-(2)-BF2, IRMOF-C'-BF2, and IRMOF-C-CH2BF2) based on IRMOF-1. A series of linkers, based on Frustrated Lewis Pairs and coumarin moieties, were attached to IRMOF-1 to obtain MOFs with photocatalytic properties. Four different linkers were used: (a) a BF2 attached to a coumarin moiety at position 3, (b) two BF2 attached to a coumarin moiety in positions 3 and 7, (c) a BF2 attached in the coumarin moiety at position 7, and (d) a CH2BF2 attached at position 3. An analysis of the adsorption properties of H2, CO2, H2O and possible CO2 photocatalytic capabilities was performed by means of computational modeling using Density Functional Theory (DFT), Time-Dependent Density Functional (TD-DFT) methods, and periodic quantum chemical wave function approach. The results show that the proposed linkers are good enough to improve the CO2 adsorption, to hold better bulk properties, and obtain satisfactory optical properties in comparison with IRMOF-1 by itself.
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Affiliation(s)
| | | | | | - Marco A. García-Revilla
- Chemistry Department, Natural and Exact Sciences Division, University of Guanajuato, Noria Alta S/N, Guanajuato 36050, Mexico; (P.C.); (J.G.H.-L.); (A.B.-J.)
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Schukraft GEM, Woodward RT, Kumar S, Sachs M, Eslava S, Petit C. Hypercrosslinked Polymers as a Photocatalytic Platform for Visible-Light-Driven CO 2 Photoreduction Using H 2 O. CHEMSUSCHEM 2021; 14:1720-1727. [PMID: 33428301 PMCID: PMC8048809 DOI: 10.1002/cssc.202002824] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 12/17/2020] [Indexed: 06/02/2023]
Abstract
The design of robust, high-performance photocatalysts is key for the success of solar fuel production by CO2 conversion. In this study, hypercrosslinked polymer (HCP) photocatalysts have been developed for the selective reduction of CO2 to CO, combining excellent CO2 sorption capacities, good general stabilities, and low production costs. HCPs are active photocatalysts in the visible light range, significantly outperforming the benchmark material, TiO2 P25, using only sacrificial H2 O. It is hypothesized that superior H2 O adsorption capacities facilitate access to photoactive sites, improving photocatalytic conversion rates when compared to sacrificial H2 . These polymers are an intriguing set of organic photocatalysts, displaying no long-range order or extended π-conjugation. The as-synthesized networks are the sole photocatalytic component, requiring no added cocatalyst doping or photosensitizer, representing a highly versatile and exciting platform for solar-energy conversion.
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Affiliation(s)
- Giulia E. M. Schukraft
- Barrer CentreDepartment of Chemical EngineeringSouth Kensington CampusImperial College LondonLondonSW7 2AZUK
| | - Robert T. Woodward
- Barrer CentreDepartment of Chemical EngineeringSouth Kensington CampusImperial College LondonLondonSW7 2AZUK
- Current address: Institute of Materials Chemistry and Research, Faculty of ChemistryUniversity of ViennaWähringer Straße 421090ViennaAustria
| | - Santosh Kumar
- Department of Chemical EngineeringImperial College LondonLondonSW7 2AZUK
| | - Michael Sachs
- Department of ChemistryWhite City CampusImperial College LondonLondonW12 0BZUK
| | - Salvador Eslava
- Department of Chemical EngineeringImperial College LondonLondonSW7 2AZUK
| | - Camille Petit
- Barrer CentreDepartment of Chemical EngineeringSouth Kensington CampusImperial College LondonLondonSW7 2AZUK
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Meconi GM, Zangi R. Adsorption-induced clustering of CO 2 on graphene. Phys Chem Chem Phys 2020; 22:21031-21041. [PMID: 32926038 DOI: 10.1039/d0cp03482g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Utilization of graphene-based materials for selective carbon dioxide capture has been demonstrated recently as a promising technological approach. In this study we report results from density functional theory calculations and molecular dynamics simulations on the adsorption of CO2, N2, and CH4 gases on a graphene sheet. We calculate adsorption isotherms of ternary and binary mixtures of these gases and reproduce the larger selectivity of CO2 to graphene relative to the other two gases. Furthermore it is shown that the confinement to two-dimensions, associated with adsorbing the CO2 gas molecules on the plane of graphene, increases their propensity to form clusters on the surface. Above a critical surface coverage (or partial pressure) of the gas, these CO2-CO2 interactions augment the effective adsorption energy to graphene, and, in part, contribute to the high selectivity of carbon dioxide with respect to nitrogen and methane. The origin of the attractive interaction between the CO2 molecules adsorbed on the surface is of electric quadrupole-quadrupole nature, in which the positively-charged carbon of one molecule interacts with the negatively-charged oxygen of another molecule. The energy of attraction of forming a CO2 dimer is predicted to be around 5-6 kJ mol-1, much higher than the corresponding values calculated for N2 and CH4. We also evaluated the adsorption energies of these gases to a graphene sheet and found that the attractions obtained using the classical force-fields might be over-exaggerated. Nevertheless, even when the magnitudes of these (classical force-field) graphene-gas interactions are scaled-down sufficiently, the tendency of CO2 molecules to cluster on the surface is still observed.
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Affiliation(s)
- Giulia Magi Meconi
- POLYMAT & Department of Applied Chemistry, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, 20018, San Sebastian, Spain
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Saranya V, Radhika R, Shankar R, Vijayakumar S. In silico studies of the inhibition mechanism of dengue with papain. J Biomol Struct Dyn 2020; 39:1912-1927. [PMID: 32249700 DOI: 10.1080/07391102.2020.1742205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Dengue virus is becoming a major global disease; the envelope protein is the major target for vaccine development against Dengue. Nowadays, the attention has focused on developing inhibitors based on Papain is a promising target for treating Dengue. In the present work, the theoretical studies of E-protein(Cys74-Glu79;Lys110)…Papain(Cys25, Asn175 and His159) complexes are analysed by Density Functional Theory (M06-2X/cc-pVDZ) method. Among the E-protein(Cys74-Glu79;Lys110)…Papain(Cys25, Asn175 and Hys159) complexes, E-protein(Glu76)…Papain(Cys25) complex has the highest interaction value of -352.22 kcal/mol. Moreover, the natural bond orbital analysis also supports the above results. The 100 ns Molecular Dynamics simulation reveals that, E-protein(Ala54-Ile129)…Papain(Cys25) complex had the lowest root mean square deviation value of 1 Å compared to the E-protein(Ala54-Ile129)… Papain(Asn175 & His159) complexes. The salt bridge formation between the Asp103 and Lys110 residues are the important stabilizing factor in E-protein(Ala54-Ile129)…Papain(Cys25) complex. This result can extend our knowledge of the functional behaviour of Papain and provides structural insight to target Envelope protein as forthcoming drug targets in Dengue.
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Huang B, Zhao R, Xu H, Deng J, Li W, Wang J, Yang H, Zhang L. Adsorption of Methylene Blue on Bituminous Coal: Adsorption Mechanism and Molecular Simulation. ACS OMEGA 2019; 4:14032-14039. [PMID: 31497721 PMCID: PMC6714604 DOI: 10.1021/acsomega.9b01812] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 08/02/2019] [Indexed: 05/31/2023]
Abstract
Coal with its complex porous medium and abundant oxygen functional groups could be used as an adsorbent to adsorb organic compounds. Adsorption experiments and molecular dynamics simulations were carried out to study the behavior of methylene blue (MB) on the surface of Wiser bituminous coal. The influence of adsorption through factors, such as pulverized coal dosage, adsorption reaction time, initial concentration, and temperature effect, was investigated. The removal efficiency of MB reached 96.5% under optimum reactive conditions. The adsorption equilibrium was accorded with a Langmuir isotherm adsorption equation. The adsorption of MB onto coal was a spontaneous process because the adsorption free energy ΔG 0 was negative. It was consistent with the conclusion of a negative interaction energy between bituminous coal and MB obtained by molecular dynamics simulation. Moreover, the density distribution along z-axis of each component molecule showed that MB molecules were adsorbed on the coal surface because of the polar interactions between the methyl groups of MB and the hydrophilic sites at the coal surface. Also, the diffusion degree of water molecule in liquid phase showed that as MB molecules formed hydrogen bonds with the water molecules, the activity of water molecules was restricted.
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