AVS 66th International Symposium & Exhibition
    2D Materials Thursday Sessions
       Session 2D+AS+BI+HC+MN+NS+PS+SS+TL-ThA

Paper 2D+AS+BI+HC+MN+NS+PS+SS+TL-ThA11
Mechanistic Understanding of the CO Hydrogenation Reaction on Defect Engineered 2D-TaS2 and 2D-MoS2 Catalysts

Thursday, October 24, 2019, 5:40 pm, Room A216

Session: Surface Chemistry, Functionalization, Bio, Energy and Sensor Applications
Presenter: Mihai Vaida, University of Central Florida
Correspondent: Click to Email
Due to global energy demands, investigation of catalytic reaction mechanisms on novel catalytic materials that can lead to efficient production of storable fuels from sustainable inputs is of central importance. In this contribution the adsorption of CO and H2 molecules, as well as the CO hydrogenation reaction are investigated on defect engineered two dimensional (2D) TaS2 and MoS2. Crystalline 2D-TaS2 and 2D-MoS2 with surface area of 1 cm2 are synthesized via a multistep process based physical vapor deposition on Cu(111). The surface composition, morphology, and electronic structure are investigated via Auger electron spectroscopy, low energy electron diffraction, scanning tunneling microscopy, scanning tunneling spectroscopy, and photoemission spectroscopy. The interaction of the molecules with the surface and the catalytic reaction mechanisms are investigated via temperature programmed desorption/reaction. No catalytic reactions have been observed on crystalline 2D materials. However, an enhanced catalytic activity is observed after the generation of sulfur vacancies via Ar sputtering. The CO hydrogenation on TaS2 occurs on low coordinated Ta atoms through the formation of formyl radical (HCO) and formaldehyde (HCOH). On 2D-MoS2, the CO hydrogenation also occurs on low coordinated Mo atoms. However, in this case the formyl radical splits to form methyldyne radical (CH), which subsequently react with other CH radical to produce acetylene (C2H2).