Catalytic conversion of methanol to larger organic molecules over crystalline forsterite: laboratory study and astrophysical implications

Li, Q.; Dai, W.; Liu, B.S.; Sarre, P.J.; Xie, M.H.; Cheung, A.S-C.

Abstract

Laboratory catalytic reactions of methanol over heated crystalline silicates (forsterite) lead to the formation of gas-phase olefinic and polycyclic aromatic hydrocarbon (PAH) molecules, and are of potential importance in astrophysical environments including hot molecular cores, protoplanetary disks and shocks. In our experiments the methanol reagent, together with intermediate and product gas-phase molecular species were detected using time-of-flight mass-spectrometry (TOF-MS). A solid deposited on the crystalline forsterite surface was examined subsequently using high-resolution transmission electron microscopy and thermal gravimetric techniques and found to comprise amorphous and graphitic carbon. The chemical players in this work – gas-phase methanol, crystalline silicates and PAHs, have been identified spectroscopically in a range of astrophysical environments including young and evolved stars, protoplanetary disks, comets, captured dust particles and meteorites. It is envisaged that reactions on bare dust grains as studied here both experimentally and theoretically through DFT calculations, can have implications for chemical transformations and conversions, in forming PAH molecules and potentially in the synthesis of prebiotic molecules.

Citation

Li, Q., Dai, W., Liu, B., Sarre, P., Xie, M., & Cheung, A.-C. (2018). Catalytic conversion of methanol to larger organic molecules over crystalline forsterite: laboratory study and astrophysical implications. Molecular astrophysics, 13, 22-29. https://doi.org/10.1016/j.molap.2018.09.002

• Journal Article Type: Article
• Acceptance Date: Sep 7, 2018
• Online Publication Date: Sep 7, 2018
• Publication Date: Nov 30, 2018
• Deposit Date: Oct 5, 2018
• Publicly Available Date: Sep 8, 2019
• Journal: Molecular Astrophysics
• Electronic ISSN: 2405-6758
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Pages: 22-29
• DOI: https://doi.org/10.1016/j.molap.2018.09.002
• Keywords: Astrochemistry; Catalysis; Crystalline silicate; Methanol; PAHs; TOF-MS; DFT
• Public URL: https://nottingham-repository.worktribe.com/output/1148262
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S2405675818300216?via%3Dihub
• Additional Information: This article is maintained by: Elsevier; Article Title: Catalytic conversion of methanol to larger organic molecules over crystalline forsterite: Laboratory study and astrophysical implications; Journal Title: Molecular Astrophysics; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.molap.2018.09.002; Content Type: article; Copyright: © 2018 Elsevier B.V. All rights reserved.
• Contract Date: Oct 5, 2018