About

Sylvia Teresse Ceyer is a Professor of Chemistry at MIT whose research group explores the atomic level dynamics of molecule-surface interactions relevant to energy production, environmental sustainability, and nanodevice templating. Her work focuses on materials that serve as catalysts, templates, or devices, with particular attention to the challenges of studying surface chemistry under ambient conditions. To address this, her group conducts experiments under ultrahigh vacuum (UHV) conditions to unambiguously probe surface mechanisms, uncovering new dissociative chemisorption processes and mechanisms responsible for the pressure gap in surface chemistry. Her research has demonstrated how to manipulate surface reactions to occur in UHV environments, enabling detailed mechanistic studies. Additionally, her group investigates the dynamics of surface chemical reactions through molecular beam-surface scattering experiments, revealing new reaction mechanisms such as atom abstraction and the role of gas-phase dissociation in surface chemistry. Professor Ceyer is also a collaborator of the MIT Energy Initiative, contributing to advancements in catalytic and surface science.

Research topics

• Computer Security
• Computer Science
• Nanotechnology
• Metallurgy
• Chemistry
• Mathematics
• Organic chemistry
• Geometry

Selected publications

• Formation of Graphene on Gold–Nickel Surface Alloys

  Journal of the American Chemical Society · 2023 · 4 citations

  Senior authorCorresponding
  • Chemistry
  • Nanotechnology
  • Metallurgy

  , as probed by high-resolution electron energy-loss spectroscopy. Dispersion measurements of the phonon modes confirm the presence of graphene. Graphene formation is observed to be maximum at 0.4 ML Au coverage. The results of these systematic molecular-level investigations open the door to graphene synthesis at the low temperatures required for integration with complementary metal-oxide-semiconductor processes.

  PublisherDOI

• Collision-Induced Surface Processes

  CRC Press eBooks · 2022

  1st authorCorresponding
  • Computer Science
  • Computer Science
  • Computer Security

  The phrase “collision-induced surface processes” refers to processes that occur as a result of the impact of the collision of a neutral atom or molecule with the surface or with an adsorbed molecule. Processes brought about by the collision of a molecule with a surface include dissociative chemisorption and ionization and are known specifically as translationally activated processes. This chapter provides a brief description of a specific example of each type of collision-induced surface process that has been identified. It discusses the significance or potential significance of the induced processes to our understanding of surface reaction mechanisms at the molecular level as well as to the technologically important fields of catalysis, chemical vapor deposition, and plasma etching. Deformation of the molecule upon impact may only be part of the mechanism for dissociation. Collision-induced absorption has been successfully employed to synthesize another high pressure species under low pressure conditions: bulk hydrogen.

  PublisherDOI

• CO Adsorption on Gold Nickel Au–Ni(111) Surface Alloys

  The Journal of Physical Chemistry C · 2019-03-06 · 11 citations

  articleSenior authorCorresponding

  The adsorption behavior of a saturated single layer of CO on a Au–Ni(111) random surface alloy at 80 K is probed by vibrational spectroscopy as a function of Au coverage. The effect of Au on the occupancy of the Ni-bridge CO site, characterized by internal stretch frequencies of 1860–1960 cm–1, is observed to extend beyond geometric site blocking, while that of the Ni-atop-bound CO site, 2060–2120 cm–1, is well described by an ideal site blocking model up to 0.51 monolayers (ML) of Au. Gold coverages beyond 0.51 ML support nonclassically bound CO, which has a frequency (2150–2160 cm–1) above that of gas phase CO. Its adsorption site is assigned to the atop site of Ni surrounded by six Au atoms, Au6Ni. These observations naturally lead to a contemporary, physical picture of the dominant electronic interactions, combining elements from the Blyholder and d-band models, including 3d/5d, 2π*, and 5σ orbital mixing as well as CO dipole–dipole coupling, that determine the progressively nonadsorptive nature of CO with Au coverage, its Ni binding sites, and stretch frequency behavior. This vibrational study illustrates that quantitative knowledge of coverages combined with a thorough analysis of spectroscopic features is key to accurately describing adsorption in this complex and nonideal system.

  PublisherDOI

• Oxygen Adsorption on Au–Ni(111) Surface Alloys

  The Journal of Physical Chemistry C · 2014-05-28 · 19 citations

  articleSenior author

  Molecular O2 dissociates upon interaction with a Ni(111) surface, as the spatial and energetic overlap between the Ni 3d electrons and the O2 antibonding orbitals is quite favorable. On a Au–Ni(111) surface alloy where the extent of this overlap is greatly reduced, exposure to O2 results in adsorption of molecular O2 characterized by three peroxo- or superoxo-like vibrational bands centered at 743, 856, and 957 cm–1 as observed by high resolution electron energy loss spectroscopy. These bands correspond to the stretch vibrational mode of O2 at respective adsorption sites of type pseudo-3-fold fcc/hcp, degenerate-pseudo-2-fold fcc/hcp and bridge, and pseudo-3-fold bridge. These unusual chemical environments are brought about by surface alloying, rather than the presence of Au clusters on Ni, and are further stabilized by a dramatic reconstruction of the top two surface layers, as explained with an idealized surface alloy model in conjunction with electronic structure considerations. The ability to adjust the relative populations of the different oxygen cohorts by varying the Au content suggests the utility of surface alloy motifs for engineering applications.

  PublisherDOI

• DESIGN OF A MOLECULAR BEAM SURFACE SCATTERING APPARATUS FOR VELOCITY AND ANGULAR DISTRIBUTION MEASUREMENTS - eScholarship

  2013-07-22

  article1st authorCorresponding

  LBL-1155 3 Pre print f -~ Submitted to the Journal of Vacuum Science Technology DESIGN OF A MOLECULAR BEAM SURFACE SCATTERING APPARATUS FOR VELOCITY AND ANGULAR DISTRIBUTION MEASURE:MENTS S.T. Ceyer, W.J. Siekhaus, and G.A. Somorjai November 1980 TWO-WEEK LOAN COPY This is a Library Copy which may be borrowed for two weeks. a personal Info. Division copy_, call Prepared for the U.S. Department of Energy under Contract W-7405-ENG-48

  Publisher

• An Exploration of Catalytic Chemistry on Au/Ni(111)

  2011-12-09

  reportOpen access1st authorCorresponding

  This project explored the catalytic oxidation chemistry that can be effected on a Au/Ni(111) surface alloy. A Au/Ni(111) surface alloy is a Ni(111) surface on which less than 60% of the Ni atoms are replaced at random positions by Au atoms. The alloy is produced by vapor deposition of a small amount of Au onto Ni single crystals. The Au atoms do not result in an epitaxial Au overlayer or in the condensation of the Au into droplets. Instead, Au atoms displace and then replace Ni atoms on a Ni(111) surface, even though Au is immiscible in bulk Ni. The two dimensional structure of the clean Ni surface is preserved. This alloy is found to stabilize an adsorbed peroxo-like O2 species that is shown to be the critical reactant in the low temperature catalytic oxidation of CO and that is suspected to be the critical reactant in other oxidation reactions. This investigation revealed a new, practically important catalyst for CO oxidation that has since been patented.

  PublisherOA PDFDOI

• CO₂ Hydrogenation to Formic Acid on Ni(111)

  The Journal of Physical Chemistry C · 2011-12-26 · 169 citations

  article

  Periodic, self-consistent, density functional theory (DFT) calculations are employed to study CO2 hydrogenation on Ni(111). CO2 hydrogenation with H adsorbed on the surface and with H absorbed in the subsurface is investigated systematically, and the respective microscopic reaction mechanisms are elucidated. We show that on Ni(111) CO2 hydrogenation to formate intermediate is more favorable than to carboxyl intermediate. The hydrogenation to formate goes through the unidentate structure that rapidly transforms into the bidentate structure. Further hydrogenation from formate to formic acid is energetically more difficult than formate formation. Formation of adsorbed formic acid from adsorbed CO2 and surface hydrogen is an endothermic reaction. Because subsurface H in Ni(111) is substantially less stable compared to surface H, its reaction with adsorbed CO2 to adsorbed formic acid is an exothermic one. Our results may have significant implications for the synthesis of liquid fuels from CO2 and for catalytic hydrogenation reactions in general.

  PublisherDOI

• CO[subscript 2] hydrogenation to formic acid on Ni(111)

  DSpace@MIT (Massachusetts Institute of Technology) · 2011-12-01

  articleOpen access

  Periodic, self-consistent, density functional theory (DFT) calculations are employed to study CO[subscript 2] hydrogenation on Ni(111). CO[subscript 2] hydrogenation with H adsorbed on the surface and with H absorbed in the subsurface is investigated systematically, and the respective microscopic reaction mechanisms are elucidated. We show that on Ni(111) CO[subscript 2] hydrogenation to formate intermediate is more favorable than to carboxyl intermediate. The hydrogenation to formate goes through the unidentate structure that rapidly transforms into the bidentate structure. Further hydrogenation from formate to formic acid is energetically more difficult than formate formation. Formation of adsorbed formic acid from adsorbed CO[subscript 2] and surface hydrogen is an endothermic reaction. Because subsurface H in Ni(111) is substantially less stable compared to surface H, its reaction with adsorbed CO[subscript 2] to adsorbed formic acid is an exothermic one. Our results may have significant implications for the synthesis of liquid fuels from CO[subscript 2] and for catalytic hydrogenation reactions in general.

  Publisher

• Mechanism and dynamics of the reaction of XeF2 with fluorinated Si(100): Possible role of gas phase dissociation of a surface reaction product in plasmaless etching

  The Journal of Chemical Physics · 2009-04-28 · 13 citations

  articleOpen accessSenior author

  Xenon difluoride is observed to react with Si-Si sigma-dimer and sigma-lattice bonds of Si(100)2 x 1 at 150 K by single and two atom abstraction at F coverages above 1 ML. As in the limit of zero F coverage, a measurable fraction of the scattered, gas phase product of single atom abstraction, XeF, is sufficiently internally excited to dissociate into F and Xe atoms before detection. Using the XeF internal energy and orientation distributions determined in the limit of zero coverage, the laws of conservation of momentum, energy, and mass are applied to the measured F velocity and angular distributions at higher coverage to simulate the Xe atom velocity and angular distributions and their intensities at higher coverage. The simulation predicts the observed Xe atom velocity and angular distributions at high coverage reasonably well, largely because the exothermicity channeled to XeF remains approximately constant as the coverage increases. This constancy is an opportune consequence of the trade-off between the attractiveness of the potential energy surface as the coverage is increased and the dynamics of the XeF product along the potential surface. The energy, momentum, and mass conservation analysis is also used to distinguish between Xe atoms that arise from XeF gas phase dissociation and Xe atoms that are produced by two atom abstraction. This distinction enables the calculation of percentages of the single and two atom abstraction pathways, as well as the percentages of the two pathways available to the Xe atom produced by two atom abstraction, inelastic scattering, and desorption. Finally, the simulation reveals that between 9% and 12% of F atoms produced by gas phase dissociation of XeF are scattered back toward the surface. These F atoms likely react readily with Si to form the higher fluorides that ultimately lead to etching. Gas phase dissociation of the scattered product of a surface reaction is a novel mechanism to explain the unique reactivity of XeF(2) to etch Si in the absence of a plasma.

  PublisherOA PDFDOI

• Atom abstraction and gas phase dissociation in the interaction of XeF2 with Si(100)

  The Journal of Chemical Physics · 2008-12-01 · 10 citations

  articleSenior author

  Xenon difluoride reacts with Si(100)2x1 by single atom abstraction whereby a dangling bond abstracts a F atom from XeF(2), scattering the complementary XeF product molecule into the gas phase, as observed in a molecular beam surface scattering experiment. Partitioning of the available reaction energy produces sufficient rovibrational excitation in XeF for dissociation of most of the XeF to occur. The resulting F and Xe atoms are shown to arise from the dissociation of gas phase XeF by demonstrating that the angle-resolved velocity distributions of F, Xe, and XeF conserve momentum, energy, and mass. Dissociation occurs within 2 A of the surface and within a vibrational period of the excited XeF molecule. Approximately an equal amount of the incident XeF(2) is observed to react by two atom abstraction, resulting in adsorption of a second F atom and scattering of a gas phase Xe atom. Two atom abstraction occurs for those XeF product molecules whose bond axes at the transition state are oriented within +/-60 degrees of the normal and with the F end pointed toward the surface.

  PublisherDOI

Recent grants

• An Investigation into the Fundamental Principles of Plasmaless Si Etching

  NSF · $586k · 2005–2009

Frequent coauthors

• Peter Wilhelm Tiedemann

  19 shared

• J. D. Beckerle

  Clemson University

  17 shared

• B. H. Mahan

  Virginia Tech

  17 shared

• A. D. Johnson

  SIL International

  15 shared

• C. Y. Ng

  University of California, Davis

  13 shared

• Gábor A. Somorjai

  University of California, Berkeley

  12 shared

• Qian Yang

  Hebei University of Technology

  12 shared

• T. H. Lin

  Xiamen University of Technology

  8 shared