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Zhang L, Lai Q, Liu Y, Li X, Zhang W, Xu X, Fang X, Xu J, Wang X. Study on the monolayer dispersion behavior of SnO 2 on ZSM-5 for NO x-SCR by C 3H 6: the remarkable promotional effects of air plasma treatment. Phys Chem Chem Phys 2022; 24:4212-4225. [PMID: 35128555 DOI: 10.1039/d1cp05567d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aiming to fabricate more practical catalysts for NOx-SCR with C3H6, SnO2/ZSM-5 having different SnO2 loadings was prepared and treated with DBD air plasma. The dispersion of SnO2 on the H-ZSM-5 support and their interactions were investigated with both experimental methods and DFT calculations. SnO2 displays evident monolayer dispersion behavior, getting a threshold of 0.271 mmol 100 m-2 support. Plasma treatment improves significantly the SnO2 dispersion, hence amplifying the monolayer dispersion threshold to 0.380 mmol 100 m-2. XPS and DFT calculations have testified that plasma treatment strengthens strongly the SnO2-ZSM-5 support interaction, mainly through donating electrons from Sn4+ to Al3+ in the support, thus improving the dispersion of SnO2 at the same loadings. Consequently, the catalytic performance is remarkably improved because of the generation of more abundant surface acid sites and superoxide species devoted to the reaction. The sample having a SnO2 loading near the monolayer dispersion threshold shows the optimal activity in the corresponding catalyst series, demonstrating an evident threshold effect. Over SnO2/ZSM-5, the reaction goes through a Langmuir-Hinshelwood pathway, involving the adsorption and activation of both NO and C3H6 molecules. Surface mono-dentate/bridged-nitrate and carbonate species are the main reaction intermediates.
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Affiliation(s)
- Lihong Zhang
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.
| | - Qiang Lai
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.
| | - Yaqian Liu
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.
| | - Xian Li
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.
| | - Wenqi Zhang
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.
| | - Xianglan Xu
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.
| | - Xiuzhong Fang
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.
| | - Junwei Xu
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.
| | - Xiang Wang
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.
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Lai Q, Liu Y, Zhang L, Li X, Qiu Z, Xu X, Fang X, Xu J, Wang X. Expounding the monolayer dispersion threshold effect of SnO2/Beta catalysts on the selective catalytic reduction of NOx (NOx-SCR) by C3H6. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111464] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Wang C, Chen W, Yang L, Wei R, Ni J, Yang Y. Insights into the roles of the morphological carbon structure and ash in the sorption of aromatic compounds to wood-derived biochars. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 693:133455. [PMID: 31362225 DOI: 10.1016/j.scitotenv.2019.07.261] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/23/2019] [Accepted: 07/17/2019] [Indexed: 05/18/2023]
Abstract
Currently, it is still lack of systematic and in-depth knowledge regarding the co-effect of carbon-based fractions and ash in the sorption behavior of biochars. Therefore, pristine wood-derived biochars (PBCs) produced at different temperatures and their corresponding de-ashed versions (DBCs) were used to determine the roles of carbon's morphological structure and ash in sorption of aromatic compounds (toluene, m-toluidine, and m-nitrotoluene) to biochars. The results showed that biochars produced at 300-400 °C (mainly uncarbonized organic matter, UCOM) and 900 °C (turbostratic carbon, TC) may have stronger partition effect and pore filling effect with π-π interaction, respectively, and thus have greater sorption coefficients (Lg Kd) than biochars produced at 600 °C (pyrogenic amorphous carbon, PAC), which are probably dominated by surface hydrophobic effect. Meanwhile, TC had a greater Lg Kd than UCOM at low adsorbate concentrations (Ce), but exhibited an opposite trend at high Ce. The Lg Kd values of DBCs are always greater than those of PBCs, indicating ash has an inhibitory effect on sorption of aromatic compounds to biochars. Furthermore, the role of ash in sorption behavior of PBCs would vary with solution pH. At a neutral pH, PBCs have the maximum sorption quantity for aromatic compounds due to the formed cation-π bond between cations of ash and aromatic compounds. However, the acidic pH enhanced the dissolution of cations in ash and the basic pH enhanced the hydroxylation of cations in ash. Therefore, both acidic and basic pH weakened the cation-π bond between ash and aromatic compounds and decreased the sorption of aromatic compounds on PBCs. The results suggest that de-ashed biochars with more UCOM or TC are effective sorbents for sequestration of aromatic compounds, and provide a well-designed method for improving the sorption efficiency of biochars.
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Affiliation(s)
- Caiting Wang
- Ministry of Education Key Laboratory of Humid Subtropical Eco-Geographical Process, Fujian Provincial Key Laboratory for Plant Eco-Physiology, College of Geographical Science, Fujian Normal University, Fuzhou, Fujian 350007, China
| | - Weifeng Chen
- Ministry of Education Key Laboratory of Humid Subtropical Eco-Geographical Process, Fujian Provincial Key Laboratory for Plant Eco-Physiology, College of Geographical Science, Fujian Normal University, Fuzhou, Fujian 350007, China.
| | - Liuming Yang
- Ministry of Education Key Laboratory of Humid Subtropical Eco-Geographical Process, Fujian Provincial Key Laboratory for Plant Eco-Physiology, College of Geographical Science, Fujian Normal University, Fuzhou, Fujian 350007, China
| | - Ran Wei
- Ministry of Education Key Laboratory of Humid Subtropical Eco-Geographical Process, Fujian Provincial Key Laboratory for Plant Eco-Physiology, College of Geographical Science, Fujian Normal University, Fuzhou, Fujian 350007, China
| | - Jinzhi Ni
- Ministry of Education Key Laboratory of Humid Subtropical Eco-Geographical Process, Fujian Provincial Key Laboratory for Plant Eco-Physiology, College of Geographical Science, Fujian Normal University, Fuzhou, Fujian 350007, China.
| | - Yusheng Yang
- Ministry of Education Key Laboratory of Humid Subtropical Eco-Geographical Process, Fujian Provincial Key Laboratory for Plant Eco-Physiology, College of Geographical Science, Fujian Normal University, Fuzhou, Fujian 350007, China
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Rajpurohit AS, Rajesh R, Muhamed RR, Jaccob M, Adaikala Baskar AJ, Kannappan V. DFT investigation of role of N - H⋯O and N - H⋯π interactions in the stabilization of the hydrogen bonded complexes of anisole with aromatic amines. Heliyon 2019; 5:e02155. [PMID: 31388586 PMCID: PMC6667824 DOI: 10.1016/j.heliyon.2019.e02155] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 07/17/2019] [Accepted: 07/22/2019] [Indexed: 11/18/2022] Open
Abstract
Theoretical investigations have been performed on hydrogen (H-) bonded complexes of two aromatic amines with anisole to investigate the effect of the methyl substituent on N - H⋯O and N - -H⋯π interactions. Natural bond orbital (NBO) and quantum theory of atoms in molecules (QTAIM) analyses were done to elucidate the nature of H- bonding. In 1:1 complexes, the total interaction energy of N-methylaniline complex is higher than that of aniline complex. The existence of bond critical point between N-H of amine and oxygen of anisole confirms weak hydrogen bonding. The energy decomposition analysis showed the role of CT in stabilizing complexes.
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Affiliation(s)
| | - R. Rajesh
- Department of Physics, Sri Vijay Vidyalaya College of Arts and Science, Nallampalli, Dharmapuri, 636807, India
| | - R. Raj Muhamed
- Department of Physics, Jamal Mohamed College, Tiruchirappalli, 621 004, India
| | - M. Jaccob
- Department of Chemistry, Loyola College, Chennai 600 034, India
| | | | - V. Kannappan
- Department of Chemistry, Presidency College, Chennai, 600 005, India
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Zhang DW, Wang H, Li ZT. Hydrogen Bonding Motifs: New Progresses. LECTURE NOTES IN CHEMISTRY 2015. [DOI: 10.1007/978-3-662-45756-6_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Azofra LM, Scheiner S. Complexation ofnSO2molecules (n= 1, 2, 3) with formaldehyde and thioformaldehyde. J Chem Phys 2014; 140:034302. [DOI: 10.1063/1.4861432] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Azofra LM, Scheiner S. Complexes containing CO2and SO2. Mixed dimers, trimers and tetramers. Phys Chem Chem Phys 2014; 16:5142-9. [DOI: 10.1039/c3cp55489a] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two stable minima for the 1 : 1 heterodimer of CO2 : SO2, both bound by about 2 kcal mol−1. Binding is dominated by charge transfer from O lone pairs of SO2to CO π* antibonding orbitals.
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Affiliation(s)
- Luis Miguel Azofra
- Instituto de Química Médica
- CSIC
- Juan de la Cierva
- Madrid, Spain
- Department of Chemistry and Biochemistry
| | - Steve Scheiner
- Department of Chemistry and Biochemistry
- Utah State University
- Logan, USA
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Adhikari U, Scheiner S. Magnitude and Mechanism of Charge Enhancement of CH··O Hydrogen Bonds. J Phys Chem A 2013; 117:10551-62. [DOI: 10.1021/jp4081788] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Upendra Adhikari
- Department
of Chemistry and
Biochemistry, Utah State University, Logan, Utah 84322-0300, United States
| | - Steve Scheiner
- Department
of Chemistry and
Biochemistry, Utah State University, Logan, Utah 84322-0300, United States
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Vall-llosera G, Huels MA, Coreno M, Kivimäki A, Jakubowska K, Stankiewicz M, Rachlew E. Photofragmentation of 2-Deoxy-D-Ribose Molecules in the Gas Phase. Chemphyschem 2008; 9:1020-9. [DOI: 10.1002/cphc.200700635] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Giustetto R, Llabrés I Xamena FX, Ricchiardi G, Bordiga S, Damin A, Gobetto R, Chierotti MR. Maya blue: a computational and spectroscopic study. J Phys Chem B 2007; 109:19360-8. [PMID: 16853500 DOI: 10.1021/jp048587h] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Maya Blue pigment, used in pre-Colombian America by the ancient Mayas, is a complex between the clay palygorskite and the indigo dye. The pigment can be manufactured by mixing palygorskite and indigo and heating to T > 120 degrees C. The most quoted hypothesis states that the dye molecules enter the microchannels which permeate the clay structure, thus creating a stable complex. Maya Blue shows a remarkable chemical stability, presumably caused by interactions formed between indigo and clay surfaces. This work aims at studying the nature of these interactions by means of computational and spectroscopic techniques. The encapsulation of indigo inside the clay framework was tested by means of molecular modeling techniques. The calculation of the reaction energies confirmed that the formation of the clay-organic complex can occur only if palygorskite is heated at temperatures well above the water desorption step, when the release of water is entropically favored. H-bonds between the clay framework and the indigo were detected by means of spectroscopic methods. FTIR spectroscopy on outgassed palygorskite and freshly synthesized Maya Blue samples showed that the presence of indigo modifies the spectroscopic features of both structural and zeolitic water, although no clear bands of the dye groups could be observed, presumably due to its very low concentration. The positions and intensities of delta(H2O) and nu(H2O) modes showed that part of the structural water molecules interact via a hydrogen bond with the C=O or N-H groups of indigo. Micro-Raman spectra clearly evidenced the presence of indigo both in original and in freshly synthesized Maya Blue. The nu(C=O) symmetric mode of Maya Blue red-shifts with respect to pure indigo, as the result of the formation of H-bonds with the nearest clay structural water. Ab initio quantum methods were applied on the indigo molecule, both isolated and linked through H-bonds with water, to calculate the magnitude of the expected vibrational shifts. Calculated and experimental vibrational shifts appeared to be in good agreement. The presence of a peak at 17.8 ppm and the shift of the N-H signal in the 1H MAS NMR spectrum of Maya Blue provide evidence of hydrogen bond interactions between indigo and palygorskite in agreement with IR and ab initio methods.
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Affiliation(s)
- Roberto Giustetto
- Dipartimento di Scienze Mineralogiche e Petrologiche, University of Turin, via V. Caluso 35, 10125 Turin, Italy.
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Yamada Y, Katsumoto Y, Ebata T. Picosecond IR-UV pump–probe spectroscopic study on the vibrational energy flow in isolated molecules and clusters. Phys Chem Chem Phys 2007; 9:1170-85. [PMID: 17325763 DOI: 10.1039/b614895f] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Intramolecular vibrational energy redistribution (IVR) and vibrational predissociation (VP) from the XH stretching vibrations, where X refers to O or C atom, of aromatic molecules and their hydrogen(H)-bonded clusters are investigated by picosecond time-resolved IR-UV pump probe spectroscopy in a supersonic beam. For bare molecules, we mainly focus on IVR of the OH stretch of phenol. We describe the IVR of the OH stretch by a two-step tier model and examine the effect of the anharmonic coupling strength and the density of states on IVR rate and mechanism by using isotope substitution. In the H-bonded clusters of phenol, we show that the relaxation of the OH stretching vibration can be described by a stepwise process and then discuss which process is sensitive to the H-bonding strength. We discuss the difference/similarity of IVR/VP between the "donor" and the "acceptor" sites in phenol-ethylene cluster by exciting the CH stretch vibrations. Finally, we study the vibrational energy transfer in the isolated molecules having the alkyl chain, namely phenylalcanol (PA). In this system, we measure the rate constant of the vibrational energy transfer between the OH stretch and the vibrations of benzene ring which are connected at the both ends of the alkyl chain. This energy transfer can be called "through-bond IVR". We investigate the three factors which are thought to control the energy transfer rate; (1) "OH <--> next CH(2)" coupling, (2) chain length and (3) conformation. We discuss the energy transfer mechanism in PAs by examining these factors.
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Affiliation(s)
- Yuji Yamada
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan
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Piracha N, Ito F, Nakanaga T. Infrared depletion spectroscopy of aniline–toluene cluster: the investigation of the red shifts of the NH2 stretching vibrations of aniline–aromatic clusters. Chem Phys 2004. [DOI: 10.1016/j.chemphys.2003.10.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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