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Gan W, Geng L, Huang B, Hansen K, Luo Z. Dehydrogenation of diborane on small Nb n+ clusters. Phys Chem Chem Phys 2024; 26:9586-9592. [PMID: 38465400 DOI: 10.1039/d3cp06135c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
The reactivity of Nbn+ (1 ≤ n ≤ 21) clusters with B2H6 is studied by using a self-developed multiple-ion laminar flow tube reactor combined with a triple quadrupole mass spectrometer (MIFT-TQMS). The Nbn+ clusters were generated by a magnetron sputtering source and reacted with the B2H6 gas under fully thermalized conditions in the downstream flow tube where the reaction time was accurately controlled and adjustable. The complete and partial dehydrogenation products NbnB1-4+ and NbnB1-4H1,2,4+ were detected, indicative of the removal of H2 and likely BHx moieties. Interestingly, these NbnB1-4+ and NbnB1-4H1,2,4+ products are limited to 3 ≤ n ≤ 6, suggesting that the small Nbn+ clusters are relatively more reactive than the larger Nbn>6+ clusters under the same conditions. By varying the B2H6 gas concentrations and the reactant doses introduced into the flow tube, and by changing the reaction time, we performed a detailed analysis of the reaction dynamics in combination with the DFT-calculated thermodynamics. It is demonstrated that the lack of cooperative active sites on the Nb1+ cations accounts for the weakened dehydrogenation efficiency. Nb2+ forms partial dehydrogenation products at a faster rate. In contrast, the Nbn>6+ clusters are subject to more flexible vibrational relaxation which disperse the energy gain of B2H6-adsorption and thus are unable to overcome the energy barriers for subsequent hydrogen atom transfer and H2 release.
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Affiliation(s)
- Wen Gan
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Lijun Geng
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Benben Huang
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Klavs Hansen
- School of Chemical Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhixun Luo
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
- Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
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Gan W, Huang B, Cui C, Hansen K, Luo Z. Weak Interactions Initiate C-H and C-C Bond Dissociation of Ethane on Nb n + Clusters. Chemphyschem 2023; 24:e202200530. [PMID: 36807961 DOI: 10.1002/cphc.202200530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/23/2023]
Abstract
The conversion of ethane into value-added chemicals under ambient conditions has attracted much attention but the mechanisms remain not fully understood. Here we report a study on the reaction of ethane with thermalized Nbn + clusters based on a multiple-ion laminar flow tube reactor combined with a triple quadrupole mass spectrometer (MIFT-TQMS). It is found that ethane reacts with Nbn + clusters to form both products of dehydrogenation and methane-removal (odd-carbon products). Combined with density functional theory (DFT) calculations, we studied the reaction mechanisms of the C-C bond activation and C-H bond cleavage on the Nbn + clusters. It is unveiled that hydrogen atom transfer (HAT) initiates the reaction process, giving rise to the formation of Nb-C bonds and an elongated C-C distance in the HNbn + CH2 CH3 motif. Subsequent reactions allow for C-C bond activation and a competitive HAT process which is associated with CH4 removal or H2 release, resulting in the production of the observed carbides.
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Affiliation(s)
- Wen Gan
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of, Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Benben Huang
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of, Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chaonan Cui
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of, Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Klavs Hansen
- Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Zhixun Luo
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of, Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
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Huang B, Wu H, Yang M, Luo Z. An integrated instrument of a tandem quadrupole mass spectrometer for cluster reaction and soft-landing deposition. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113307. [PMID: 36461460 DOI: 10.1063/5.0112401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 10/11/2022] [Indexed: 06/17/2023]
Abstract
We have developed an integrated instrument system of a multiple-ion laminar flow tube (MIFT) reactor combined with a tandem quadrupole mass spectrometer (TQMS) and soft-landing deposition (SD) apparatus. A customized water-cooling magnetron sputtering (MagS) source is designed, by which we are able to attain a highly efficient preparation of metal clusters of 1-30 atoms with tunable size distributions. Following the MagS source, a laminar flow tube reactor is designed, allowing for sufficient gas-collision reactions of the as-prepared metal clusters, which is advantageous for probing magic clusters and minimizing wall effects when probing the reaction dynamics of such clusters. The customized TQMS analyzer involves a conical octupole, two linear octupoles, a quadruple ion deflector, and a 19 mm quadruple mass analyzer, allowing to decrease the pressure stepwise (from ∼5 to ∼10-9 Torr), thus ensuring high sensitivity and high resolution of the mass spectrometry analysis. In addition, we have designed a dual SD apparatus for the mass-selected deposition of clusters and their reaction products. For the whole system, abbreviated as MagS-MIFT-TQMS-SD, we have performed a detailed ions-fly simulation and quantitatively estimated the ions transfer efficiency under vacuum conditions determined by real experiments. Taking these advantages, well-resolved Pbn +, Agn +, and Nbn + clusters have been produced, allowing for meticulous studies of cluster reactions under sufficient gas-phase collisions free of electric field trapping. Also, we have tested the efficiency of the dual SD.
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Affiliation(s)
- Benben Huang
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Haiming Wu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Mengzhou Yang
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhixun Luo
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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