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Rai PK, Sarkar S, Bandyopadhyay B, Kumar P. Oxidation of HOSO˙ by O 2 ( 3Σ g-): a key reaction deciding the fate of HOSO˙ in the atmosphere. Phys Chem Chem Phys 2022; 24:16274-16280. [PMID: 35758329 DOI: 10.1039/d2cp00001f] [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
In the present work, we have studied the oxidation of HOSO˙ by O2 (3Σg-) employing quantum chemical and kinetic calculations. The present work reveals that HOSO˙ + O2 (3Σg-) is a barrierless reaction which proceeds through a stable hydrogen-bonded complex. The estimated atmospheric lifetime of HOSO˙ in the presence of O2 (3Σg-) is found to be several orders of magnitude less compared to the other oxidation paths of HOSO˙, suggesting that the oxidation of HOSO˙ by O2 (3Σg-) might be the most dominant oxidation path of HOSO˙ in the atmosphere.
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Affiliation(s)
- Philips Kumar Rai
- Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India.
| | - Saptarshi Sarkar
- Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India.
| | - Biman Bandyopadhyay
- Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India.
| | - Pradeep Kumar
- Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India.
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Zhang T, Zhai K, Zhang Y, Geng L, Geng Z, Zhou M, Lu Y, Shao X, Lily M. Effect of water and ammonia on the HO + NH3 → NH2 + H2O reaction in troposphere: Competition between single and double hydrogen atom transfer pathways. COMPUT THEOR CHEM 2020. [DOI: 10.1016/j.comptc.2020.112747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Li W, Shang Y, Ning H, Li J, Luo SN. Reaction pathways and kinetics study on a syngas combustion system: CO + HO 2 in an H 2O environment. Phys Chem Chem Phys 2020; 22:5797-5806. [PMID: 32105282 DOI: 10.1039/c9cp06642j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The reaction between CO and HO2 plays a significant role in syngas combustion. In this work, the catalytic effect of single-molecule water on this reaction is theoretically investigated at the CCSD(T)/aug-cc-pV(D,T,Q)Z and CCSD(T)-F12a/jun-cc-pVTZ levels in combination with the M062X/aug-cc-pVTZ level. Firstly, the potential energy surface (PES) of CO + HO2 (water-free) is revisited. The major products CO2 + OH are formed via a cis- or a trans-transition state (TS) channel and the formation of HCO + O2 is minor. In the presence of water, the title reaction has three different pre-reactive complexes (i.e., RC2: COHO2 + H2O, RC3: COH2O + HO2, and RC4: HO2H2O + CO), depending on the initial hydrogen bond formation. Compared to the water-free process, the reaction barriers of the water-assisted process are reduced considerably, due to more stable cyclic TSs and complexes. The rate constants for the bimolecular reaction pathways CO + HO2, RC2, RC3, and RC4 are further calculated using conventional transition state theory (TST) with Eckart asymmetric tunneling correction. For reaction CO + HO2, our calculations are in good agreement with the literature. In addition, the effective rate constants for the water-assisted process decrease by 1-2 orders of magnitude compared to the water-free one at a temperature below 600 K. In particular, the effective rate constants for the water-assisted and water-free processes are 1.55 × 10-28 and 3.86 × 10-26 cm3 molecule-1 s-1 at 300 K, respectively. This implies that the contribution of a single molecule water-assisted process is small and cannot accelerate the title reaction.
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Affiliation(s)
- Wenrui Li
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, and Institute of Material Dynamics, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China. and School of Chemistry and Chemical Engineering & Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China.
| | - Yanlei Shang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, and Institute of Material Dynamics, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China.
| | - Hongbo Ning
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, and Institute of Material Dynamics, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China.
| | - Jun Li
- School of Chemistry and Chemical Engineering & Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China.
| | - Sheng-Nian Luo
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, and Institute of Material Dynamics, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China. and The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610031, P. R. China
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Zhang T, Wen M, Zeng Z, Lu Y, Wang Y, Wang W, Shao X, Wang Z, Makroni L. Effect of NH 3 and HCOOH on the H 2O 2 + HO → HO 2 + H 2O reaction in the troposphere: competition between the one-step and stepwise mechanisms. RSC Adv 2020; 10:9093-9102. [PMID: 35496523 PMCID: PMC9050117 DOI: 10.1039/d0ra00024h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 02/13/2020] [Indexed: 11/21/2022] Open
Abstract
The H2O2 + HO → HO2 + H2O reaction is an important reservoir for both radicals of HO and HO2 catalyzing the destruction of O3. Here, this reaction assisted by NH3 and HCOOH catalysts was explored using the CCSD(T)-F12a/cc-pVDZ-F12//M06-2X/aug-cc-pVTZ method and canonical variational transition state theory with small curvature tunneling. Two possible sets of mechanisms, (i) one-step routes and (ii) stepwise processes, are possible. Our results show that in the presence of both NH3 and HCOOH catalysts under relevant atmospheric temperature, mechanism (i) is favored both energetically and kinetically than the corresponding mechanism (ii). At 298 K, the relative rate for mechanism (i) in the presence of NH3 (10, 2900 ppbv) and HCOOH (10 ppbv) is respectively 3–5 and 2–4 orders of magnitude lower than that of the water-catalyzed reaction. This is due to a comparatively lower concentration of NH3 and HCOOH than H2O which indicates the positive water effect under atmospheric conditions. Although NH3 and HCOOH catalysts play a negligible role in the reservoir for both radicals of HO and HO2 catalyzing the destruction of O3, the current study provides a comprehensive example of how acidic and basic catalysts assisted the gas-phase reactions. The H2O2 + HO → HO2 + H2O reaction is an important reservoir for both radicals of HO and HO2 catalyzing the destruction of O3.![]()
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Affiliation(s)
- Tianlei Zhang
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Mingjie Wen
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Zhaopeng Zeng
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Yousong Lu
- Key Laboratory for Macromolecular Science of Shaanxi Province
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- Xi'an
- P. R. China
| | - Yan Wang
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Wei Wang
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Xianzhao Shao
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Zhiyin Wang
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Lily Makroni
- Key Laboratory for Macromolecular Science of Shaanxi Province
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- Xi'an
- P. R. China
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Zhang T, Wen M, Zhang Y, Lan X, Long B, Wang R, Yu X, Zhao C, Wang W. Atmospheric chemistry of the self-reaction of HO 2 radicals: stepwise mechanism versus one-step process in the presence of (H 2O) n (n = 1-3) clusters. Phys Chem Chem Phys 2019; 21:24042-24053. [PMID: 31646308 DOI: 10.1039/c9cp03530c] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of water on radical-radical reactions are of great importance for the elucidation of the atmospheric oxidation process of free radicals. In the present work, the HO2 + HO2 reactions with (H2O)n (n = 1-3) have been investigated using quantum chemical methods and canonical variational transition state theory with small curvature tunneling. We have explored both one-step and stepwise mechanisms, in particular the stepwise mechanism initiated by ring enlargement. The calculated results have revealed that the stepwise mechanism is the dominant one in the HO2 + HO2 reaction that is catalyzed by one water molecule. This is because its pseudo-first-order rate constant (kRWM1') is 3 orders of magnitude larger than that of the corresponding one-step mechanism. Additionally, the value of kRWM1' at 298 K has been found to be 4.3 times larger than that of the rate constant of the HO2 + HO2 reaction (kR1) without catalysts, which is in good agreement with the experimental findings. The calculated results also showed that the stepwise mechanism is still dominant in the (H2O)2 catalyzed reaction due to its higher pseudo-first-order rate constant, which is 3 orders of magnitude larger than that of the corresponding one-step mechanism. On the other hand, the one-step process is much faster than the stepwise mechanism by a factor of 105-106 in the (H2O)3 catalyzed reaction. However, the pseudo-first-order rate constants for the (H2O)2 and (H2O)3-catalyzed reactions are lower than that of the H2O-catalyzed reaction by 3-4 orders of magnitude, which indicates that the water monomer is the most efficient one among all the catalysts of (H2O)n (n = 1-3). The present results have provided a definitive example that water and water clusters have important influences on atmospheric reactions.
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Affiliation(s)
- Tianlei Zhang
- Shaanxi Key Laboratory of Catalysis, School of Chemical & Environment Science, Shaanxi University of Technology, Hanzhong, Shaanxi 723001, P. R. China.
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