@article{972839e14de441c28f747b81d47503d5,
title = "Morphology and CO Oxidation Activity of Pd Nanoparticles on SrTiO3 Nanopolyhedra",
abstract = "Single crystal SrTiO3 nanocuboids having primarily TiO2-(001) surfaces and nanododecahedra having primarily (110) surfaces were created by two separate hydrothermal synthesis processes. Pd nanoparticles grown on the two sets of STO nanopolyhedra by atomic layer deposition show different morphologies and CO oxidation performance. Transmission electron microscopy and small-angle X-ray scattering show that 2-3 nm Pd nanoparticles with 3-5 nm interparticle distances decorate the STO surfaces. When the number of ALD cycles increases, the growth of the Pd nanoparticles is more significant in size on TiO2-(001)-STO surfaces, while that on (110)-STO surfaces is more predominant in number. High resolution electron microscopy images show that single crystal and multiply twinned Pd nanoparticles coexist on both types of the STO nanopolyhedra and exhibit different degrees of adhesion. The CO oxidation reaction, which was employed to determine the dependence of catalytic activity, showed that the Pd catalytic performance was dominated by the coverage of CO, which is more directly related to Pd nanoparticle size than to shape. CO turnover frequency analysis and diffuse reflectance infrared Fourier transform spectroscopy show that regardless of the shape or degrees of wetting, larger Pd nanoparticles (∼3 nm) have lower catalytic activity due to high CO coverage on nanoparticle facets. Smaller nanoparticles (∼2 nm) have more edge and corner sites and exhibit 2-3 times higher TOF at 80 and 100 °C.",
keywords = "CO oxidation, X-ray absorption near edge structure, X-ray small angle scattering, atomic layer deposition, diffuse reflectance infrared Fourier transform spectroscopy, heterogeneous catalysts, palladium, strontium titanate",
author = "Chen, {Bor Rong} and Crosby, {Lawrence A.} and Cassandra George and Kennedy, {Robert M.} and Schweitzer, {Neil M.} and Jianguo Wen and {Van Duyne}, {Richard P.} and Stair, {Peter C.} and Poeppelmeier, {Kenneth R.} and Marks, {Laurence D.} and Bedzyk, {Michael J.}",
note = "Funding Information: This work was supported by the Institute for Catalysis in Energy Processes (ICEP) at Northwestern University (NU) under DOE Grant DE-FG02-03ER15457. X-ray measurements were performed at the Advanced Photon Source of Argonne National Lab (ANL), at DND-CAT (Sector 5), which is supported by E.I. DuPont de Nemours & Co., NU, and The Dow Chemical Co. ANL is supported by DOE under grant number DE-AC02-06CH11357. We thank Qing Ma and Steve Weigand at DND-CAT for assisting with the XANES and SAXS measurements. Electron microscopy was performed at the EPIC facility supported by the NU-MRSEC program (NSF DMR-1720139) and at the UIC Research Resources Center supported by an MRI-R2 grant from the National Science Foundation (NSF DMR-0959470). Use of aberration-corrected TEM at the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The TOF analysis and DRIFTS were performed at the Clean Catalysis Core facility, which acknowledges funding from the Department of Energy (DE-FG02-03ER15457 and DE-AC02-06CH11357) used for the purchase of the Thermo 6700 DRIFTS system and the Altamira AMI-200. ICP-AES measurements were performed at the Northwestern University Quantitative Bio-element Imaging Center. B.R.C. was partially supported by Study Abroad Fellowship from Ministry of Education of Taiwan. L.A.C. is supported by a National Science Foundation Graduate Research Fellowship. Publisher Copyright: {\textcopyright} 2018 American Chemical Society.",
year = "2018",
month = jun,
day = "1",
doi = "10.1021/acscatal.7b04173",
language = "English (US)",
volume = "8",
pages = "4751--4760",
journal = "ACS Catalysis",
issn = "2155-5435",
publisher = "American Chemical Society",
number = "6",
}