1
|
Ciborowski SM, Buszek R, Liu G, Blankenhorn M, Zhu Z, Marshall MA, Harris RM, Chiba T, Collins EL, Marquez S, Boatz JA, Chambreau SD, Vaghjiani GL, Bowen KH. Study of the Reaction of Hydroxylamine with Iridium Atomic and Cluster Anions ( n = 1-5). J Phys Chem A 2021; 125:5922-5932. [PMID: 34229436 DOI: 10.1021/acs.jpca.1c03935] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Elucidating the multifaceted processes of molecular activation and subsequent reactions gives a fundamental view into the development of iridium catalysts as they apply to fuels and propellants, for example, for spacecraft thrusters. Hydroxylamine, a component of the well-known hydroxylammonium nitrate (HAN) ionic liquid, is a safer alternative and mimics the chemistry and performance standards of hydrazine. The activation of hydroxylamine by anionic iridium clusters, Irn- (n = 1-5), depicts a part of the mechanism, where two hydrogen atoms are removed, likely as H2, and Irn(NOH)- clusters remain. The significant photoelectron spectral differences between these products and the bare clusters illustrate the substantial electronic changes imposed by the hydroxylamine fragment on the iridium clusters. In combination with DFT calculations, a preliminary reaction mechanism is proposed, identifying the possible intermediate steps leading to the formation of Ir(NOH)-.
Collapse
Affiliation(s)
- Sandra M Ciborowski
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Robert Buszek
- Jacobs Technology, Inc., Air Force Research Laboratory, AFRL/RQRP, Edwards Air Force Base, California 93524, United States
| | - Gaoxiang Liu
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Moritz Blankenhorn
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Zhaoguo Zhu
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Mary A Marshall
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | | | - Tatsuya Chiba
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Evan L Collins
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Sara Marquez
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Jerry A Boatz
- Propellants Branch, Rocket Propulsion Division, Aerospace Systems Directorate, Air Force Research Laboratory, AFRL/RQRP, Edwards Air Force Base, California 93524, United States
| | - Steven D Chambreau
- Jacobs Technology, Inc., Air Force Research Laboratory, AFRL/RQRP, Edwards Air Force Base, California 93524, United States
| | - Ghanshyam L Vaghjiani
- In-Space Propulsion Branch, Rocket Propulsion Division, Aerospace Systems Directorate, Air Force Research Laboratory, AFRL/RQRS, Edwards Air Force Base, California 93524, United States
| | - Kit H Bowen
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| |
Collapse
|
2
|
Koyasu K, Tomihara R, Nagata T, Wu JWJ, Nakano M, Ohshimo K, Misaizu F, Tsukuda T. Sequential growth of iridium cluster anions based on simple cubic packing. Phys Chem Chem Phys 2020; 22:17842-17846. [DOI: 10.1039/d0cp03122d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ion mobility measurements and DFT calculations revealed cubic growth of Irn− in contrast to fcc structures in bulk and nanoparticles.
Collapse
Affiliation(s)
- Kiichirou Koyasu
- Department of Chemistry, Graduate School of Science
- The University of Tokyo, 7-3-1 Hongo
- Tokyo 113-0033
- Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB)
| | - Ryohei Tomihara
- Department of Chemistry, Graduate School of Science
- The University of Tokyo, 7-3-1 Hongo
- Tokyo 113-0033
- Japan
| | - Toshiaki Nagata
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Jenna W. J. Wu
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Motoyoshi Nakano
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Keijiro Ohshimo
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Fuminori Misaizu
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Tatsuya Tsukuda
- Department of Chemistry, Graduate School of Science
- The University of Tokyo, 7-3-1 Hongo
- Tokyo 113-0033
- Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB)
| |
Collapse
|
5
|
Chen M, Dixon DA. Low-Lying Electronic States of Irn Clusters with n = 2–8 Predicted at the DFT, CASSCF, and CCSD(T) Levels. J Phys Chem A 2013; 117:3676-88. [DOI: 10.1021/jp4014465] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mingyang Chen
- Department of Chemistry, The University of Alabama, Shelby Hall, Box 870336, Tuscaloosa, Alabama
35487-0336, United States
| | - David A. Dixon
- Department of Chemistry, The University of Alabama, Shelby Hall, Box 870336, Tuscaloosa, Alabama
35487-0336, United States
| |
Collapse
|
6
|
Nakanaga T, Nagai H, Saito N, Fujiwara Y, Nonaka H. Stabilities and dissociation reactions of the Irm(CO)n+ ions observed in TOF-SIMS of Ir4(CO)12 thin layer. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2012.11.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
7
|
Abstract
The energetics and the electronic and magnetic properties of iridium nanoparticles in the range of 2-64 atoms were investigated using density functional theory calculations. A variety of different geometric configurations were studied, including planar, three-dimensional, nanowire, and single-walled nanotube. The binding energy per atom increases with size and dimensionality from 2.53 eV/atom for the iridium dimer to 6.09 eV/atom for the 64-atom cluster. The most stable geometry is planar until four atoms are reached and three-dimensional thereafter. The simple cubic structure is the most stable geometric building block until a strikingly large 48-atom cluster, when the most stable geometry transitions to face-centered cubic, as found in the bulk metal. The strong preference for cubic structure among small clusters demonstrates their rigidity. This result indicates that iridium nanoparticles intrinsically do not favor the coalescence process. Nanowires formed from linear atomic chains of up to 4-atom rings were studied, and the wires formed from 4-atom rings were extremely stable. Single-walled nanotubes were also studied. These nanotubes were formed by stacking 5- and 6-atom rings to form a tube. The ring stacking with each atom directly above the previous atom is more stable than if the alternate rings are rotated.
Collapse
Affiliation(s)
- Tiffany Pawluk
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
| | | | | |
Collapse
|
8
|
Abstract
To contribute to the understanding of how iridium particles act as catalysts for hydrogenation and dehydrogenation of hydrocarbons, we have determined structures and binding energies of various isomers of Ir(4) as well as HIr(4) on the basis of relativistic density functional theory. The most stable isomer of Ir(4) showed a square planar structure with eight unpaired electrons. The tetrahedral structure, experimentally suggested for supported species, was calculated 49 kJ mol(-1) less stable. Hydrogen coordinates preferentially to a single Ir center of the planar cluster with a binding energy of up to 88 kJ mol(-1) with respect to the atom in the H(2) molecule. Terminal interaction of hydrogen with an Ir(4) tetrahedron causes the cluster to open to a butterfly structure. We calculated terminal binding of hydrogen at different Ir(4) isomers to be more stable than bridge coordination, at variance with earlier studies.
Collapse
Affiliation(s)
- Chuenchit Bussai
- Department Chemie, Theoretische Chemie, Technische Universität München, 85747 Garching, Germany
| | | | | | | |
Collapse
|