印第安纳大学 Prof. Dr. Steven L. Tait 6月28日上午学术报告

Presenter: Prof. Steven L. Tait (Department of Chemistry, Indiana University)

Topic: Single-site Catalysts by Metal-ligand Complexation at Surfaces: From Model Systems in Vacuum to High-pressure Catalysis on Oxide Supports

Time: 10:00 AM, June. 28th (Friday)

Location: Conference Room B, BLDG 909-1F

Abstract

A grand challenge in heterogeneous catalysis is to achieve high levels of selectivity by controlling the chemical uniformity of metal catalyst sites at surfaces. Our group is working to develop a better understanding of fundamental aspects of self-assembly and organic film growth at surfaces [1] and to apply principles of on-surface metal-organic redox assembly to develop a new approach to this problem. Metal-organic coordination networks at surfaces hold promise for selective chemical function, but there is a limited understanding of the chemical reactivity of these systems. We tested chemical activity of vanadium single-site complexes that are stabilized by tetrazine-based ligands. We demonstrate activity toward dioxygen activation and a high degree of selectivity compared to vanadium nanoparticles. Reaction with O2 causes an increase in V oxidation state from VII to VIV, resulting in a single strongly bonded V-oxo product and spillover of O to the Au surface [2]. The metal centers are stabilized in extended, ordered metal-organic complexes that self-assemble through an on-surface redox process on the Au(100) surface and are characterized by X-ray photoelectron spectroscopy, scanning tunneling microscopy, high-resolution electron energy loss spectroscopy, and density functional theory. New results extend these chemical studies to more complex systems that include bimetallic sites [3] and redox isomer systems [4], which will also be highlighted in this presentation.

1. D. L. Wisman, S. Kim, T. W. Morris, J. Choi, C. D. Tempas, C. Q. Trainor, D. Lee, and S. L. Tait, “Surface Self-Assembly, Film Morphology, and Charge Transport Properties of Semiconducting Triazoloarenes,” Langmuir, 35, 6304-6311 (2019). DOI: 10.1021/acs.langmuir.9b00512

2. C. D. Tempas, T. W. Morris, D. L. Wisman, D. Le, N. U. Din, C. G. Williams, M. Wang, A. V. Polezhaev, T. S. Rahman, K. G. Caulton, and S. L. Tait, Redox-active Ligand Controlled Selectivity of Vanadium Oxidation on Au(100), Chemical Science, 9, 1674-1685 (2018). DOI: 10.1039/C7SC04752E

3. T. W. Morris, I. J. Huerfano, M. Wang, D. L. Wisman, A. C. Cabelof, N. U. Din, C. D. Tempas, D. Le, A. V. Polezhaev, T. S. Rahman, K. G. Caulton, S. L. Tait, “Multi-electron Reduction Capacity and Multiple Binding Pockets in Metal-organic Redox Assembly at Surfaces,” Chemistry – a European Journal, 25, 5565-5573 (2019). DOI: 10.1002/chem.201900002

4. C. D. Tempas, D. Skomski, B. J. Cook, D. Le, K. A. Smith, T. S. Rahman, K. G. Caulton, and S. L Tait, Redox Isomeric Surface Structures are Preferred over Odd‐electron Pt(1+), Chemistry - a European Journal, 24, 15852–15858 (2018). DOI: 10.1002/chem.201802943

Biography

Education and Academic Career

Indiana University, Department of Chemistry (IU)

Professor, 2019 - Present

Associate Professor, 2015 – 2019

Assistant Professor, August 2008 – 2015

Adjunct Professor of Physics, September 2012 – Present

Max Planck Institute for Solid State Research (MPI), 70569 Stuttgart, Germany

Postdoc advisor: Prof. Dr. Klaus Kern

Alexander von Humboldt Postdoctoral Fellow, July 2005 – 2007

Group Leader and Max Planck Postdoctoral Fellow, July 2007 – July 2008

University of Washington (UW), Seattle, Washington 98195

Ph.D. in Physics, Dual Degree Program in Nanotechnology, June 2005

Thesis: “Desorption Kinetics of Small n-alkanes from MgO(100), Pt(111), and

C(0001)-Pt(111) and Studies of Pd Nanoparticles: Growth and Sintering on

Al 2 O 3 (0001) and Methane Dissociation on MgO(100)”

Thesis advisors: Professor Charles T. Campbell, Department of Chemistry

Professor Samuel C. Fain, Jr. (deceased), Department of Physics

Graduate research fellowship award for research at Pacific Northwest National

Laboratory (PNNL), Advisor: Dr. Bruce D. Kay, 2002-2005

M.S. in Physics, June 2002

Brigham Young University (BYU), Provo, Utah 84602

B.S. in Honors Physics and University Honors (Honors Thesis), August 2000

Contact: Prof. Lifeng Chi