Coupling Reactions of Formaldehyde on Rutile TiO$_{\mathrm{2}}$(110)

ORAL

Abstract

We have studied reactions of formaldehyde on reduced rutile TiO$_{\mathrm{2}}$(110) surfaces using scanning tunneling microscope (STM). Images from the same area at viable temperatures (75 $-$ 170 K) show two coupling reactions channels. Formaldehyde adsorbed on bridging-bonded oxygen vacancy (V$_{\mathrm{O}})$ couples with Ti-bound CH$_{\mathrm{2}}$O form a diolate species, which stays stable at room temperature. Consequently, exposure of formaldehyde at room temperature leads to diolate as the majority species on the surface and no V$_{\mathrm{O}}$-bound formaldehyde is observed. STM images directly visualize a second coupling reaction channel, a low-temperature channel. Two V$_{\mathrm{O}}$-bound formaldehyde molecules can couple and form Ti-bound species, which desorbs above 215 K. This coupling reaction heals both the V$_{\mathrm{O}}$ sites indicating formation and desorption of ethylene. Statistical analysis shows that the total visible reaction products observed on the surfaces can only account for a half of the consumption of the initial V$_{\mathrm{O}}$ coverage, which further supports the desorption of the coupling reaction product, ethylene, after formaldehyde exposures between 215 and 300 K.

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Authors

  • Zhenrong Zhang

    Baylor University, Waco, TX 76798, Baylor University

  • Ke Zhu

    Baylor University, Waco, TX 76798

  • Yaobiao Xia

    Baylor University, Waco, TX 76798

  • Harry A. Atwater

    Institute for Advanced Physics and Mathematics, Zhejiang University of Technology, Baylor University, baylor university, Lanzhou Jiaotong University, Lanzhou University, Trinity University, University of New Hampshire, Los Alamos National Lab, Southwest Research Institute, University of Texas San Antonio, Texas A&M University, Department of Physics, Texas State University, San Marcos, TX78666, None, Southern Illinois University, Carbondale, Illinois 62901, Beijing Computational Science Research Center, Beijing 100094, P.R. China, The State Key Laboratory of Quantum Optics and Quantum Optics Devices, China, COMSATS Institute of Information Technology, Islamabad, Pakistan, Lamar University, NIST, NIST Physical Measurement Laboratory,Thermodynamic Metrology Laboratory, Rice University, University of Texas at Rio Grande Valley, University of Texas at Dallas, Texas Tech University, Department of Physics and Astronomy, Texas A\&M University, Russian Quantum Center, Physics Department, International Laser Center, M.V. Lomonosov Moscow State University, Baylor University, Texas A&M University, Princeton University, Baylor University, Texas A&M University, Florida State University, Univ of Texas, Dallas, University of Texas Rio Grande Valley, University of Houston, Physics and Astronomy, Material Science and Eng,Texas A\&M University. WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, Japan, Physics and Astronomy, Texas A\&M University, Material Science and Eng., Texas A\&M University, Texas Christian University, Utaca College, University of Texas at Arlington, Angelo State University Physics & Geosciences Department, Texas State University, Universidade Federal de Viçosa, Department of Physics, Lamar University, Texas Lutheran University, University of Oklahoma, Texas A&M University, Baylor University, Princeton University, Texas A&M University, Baylor University, Institute for Quantum Science and Engineering (IQSE) and Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843-4242, Texas A\&M University, Florida A&M University, Texas A&M University, Princeton University, Baylor University, Department of Physics and Astronomy, Texas A&M University, College Station, TX, Texas A&M University and Baylor University, Abilene Christian University, Michigan State University, Argonne National Laboratory, Southern Methodist University, University of Maryland, Baltimore County, Baltimore, MD 21250, Institute for Quantum Science and Engineering, Texas A&M University 4242 TAMU College Station, Texas 77843-4242, The Institute for Quantum Science and Engineering, Texas A&M University, Southern Nazarene University, Texas A&M University, Landau Institute for Theoretical Physics, University of Cologne, Department of Physics, The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, Texas 75080, USA, Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA, $^{1}$Department of Physics and Astronomy, Texas A\&M University, $^{1}$Department of Physics and Astronomy, Texas A\&M University, $^{2}$WPI-AIMR, Tohoku University, Japan, Department of Physics, Austin College, AMRIS/NHMFL, University of Florida, University of Texas Southwestern Medical Center, Mississippi State University, The Methodist Hospital System, Biophotonic Solutions, Inc., University of Texas, Austin, California Insititute of Technology

  • Zhi-Tao Wang

    Pacific Northwest National Laboratory, Richland, Washington 99352

  • Igor Lyubinetsky

    Pacific Northwest National Laboratory, Richland, Washington 99352

  • Gingfeng Ge

    Southern Illinois University, Carbondale, Illinois 62901

  • Zdenek Dohnalek

    Pacific Northwest National Laboratory, Richland, Washington 99352

  • Kenneth Park

    Baylor University, Waco, TX 76798