skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Adsorbate-mediated strong metal–support interactions in oxide-supported Rh catalysts

Abstract

The optimization of supported metal catalysts predominantly focuses on engineering the metal site, for which physical insights based on extensive theoretical and experimental contributions have enabled the rational design of active sites. Although it is well known that supports can influence the catalytic properties of metals, insights into how metal–support interactions can be exploited to optimize metal active-site properties are lacking. Here in this paper, we utilize in situ spectroscopy and microscopy to identify and characterize a support effect in oxide-supported heterogeneous Rh catalysts. This effect is characterized by strongly bound adsorbates (HCO x) on reducible oxide supports (TiO 2 and Nb 2O 5) that induce oxygen-vacancy formation in the support and cause HCO x-functionalized encapsulation of Rh nanoparticles by the support. The encapsulation layer is permeable to reactants, stable under the reaction conditions and strongly influences the catalytic properties of Rh, which enables rational and dynamic tuning of CO 2-reduction selectivity.

Authors:
 [1];  [2];  [1];  [3];  [4];  [2];  [5];  [6]
  1. University of California, Riverside, CA (United States). Department of Chemical and Environmental Engineering
  2. University of California, Irvine, CA (United States). Department of Chemical Engineering and Materials Science; Univ. of Michigan, Ann Arbor, MI (United States). Department of Materials Science and Engineering
  3. Columbia Univ., New York, NY (United States). Department of Chemical Engineering,
  4. Columbia Univ., New York, NY (United States). Department of Chemical Engineering; Brookhaven National Lab. (BNL), Upton, NY (United States). Chemistry Department
  5. University of California, Irvine, CA (United States). Department of Chemical Engineering and Materials Science and Department of Physics and Astronomy
  6. University of California, Riverside, CA (United States). Department of Chemical and Environmental Engineering, Program in Materials Science, and UCR Center for Catalysis
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
OSTI Identifier:
1358016
Report Number(s):
BNL-113828-2017-JA
Journal ID: ISSN 1755-4330; R&D Project: CO035; KC0302010
Grant/Contract Number:
SC0012704; SC0012335; CHE-1301019; CBET-1159240; DMR-0723032
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Nature Chemistry
Additional Journal Information:
Journal Volume: 9; Journal Issue: 2; Journal ID: ISSN 1755-4330
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Catalytic mechanisms; Heterogeneous catalysis

Citation Formats

Matsubu, John C., Zhang, Shuyi, DeRita, Leo, Marinkovic, Nebojsa S., Chen, Jingguang G., Graham, George W., Pan, Xiaoqing, and Christopher, Phillip. Adsorbate-mediated strong metal–support interactions in oxide-supported Rh catalysts. United States: N. p., 2016. Web. doi:10.1038/NCHEM.2607.
Matsubu, John C., Zhang, Shuyi, DeRita, Leo, Marinkovic, Nebojsa S., Chen, Jingguang G., Graham, George W., Pan, Xiaoqing, & Christopher, Phillip. Adsorbate-mediated strong metal–support interactions in oxide-supported Rh catalysts. United States. doi:10.1038/NCHEM.2607.
Matsubu, John C., Zhang, Shuyi, DeRita, Leo, Marinkovic, Nebojsa S., Chen, Jingguang G., Graham, George W., Pan, Xiaoqing, and Christopher, Phillip. 2016. "Adsorbate-mediated strong metal–support interactions in oxide-supported Rh catalysts". United States. doi:10.1038/NCHEM.2607. https://www.osti.gov/servlets/purl/1358016.
@article{osti_1358016,
title = {Adsorbate-mediated strong metal–support interactions in oxide-supported Rh catalysts},
author = {Matsubu, John C. and Zhang, Shuyi and DeRita, Leo and Marinkovic, Nebojsa S. and Chen, Jingguang G. and Graham, George W. and Pan, Xiaoqing and Christopher, Phillip},
abstractNote = {The optimization of supported metal catalysts predominantly focuses on engineering the metal site, for which physical insights based on extensive theoretical and experimental contributions have enabled the rational design of active sites. Although it is well known that supports can influence the catalytic properties of metals, insights into how metal–support interactions can be exploited to optimize metal active-site properties are lacking. Here in this paper, we utilize in situ spectroscopy and microscopy to identify and characterize a support effect in oxide-supported heterogeneous Rh catalysts. This effect is characterized by strongly bound adsorbates (HCOx) on reducible oxide supports (TiO2 and Nb2O5) that induce oxygen-vacancy formation in the support and cause HCOx-functionalized encapsulation of Rh nanoparticles by the support. The encapsulation layer is permeable to reactants, stable under the reaction conditions and strongly influences the catalytic properties of Rh, which enables rational and dynamic tuning of CO2-reduction selectivity.},
doi = {10.1038/NCHEM.2607},
journal = {Nature Chemistry},
number = 2,
volume = 9,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 7works
Citation information provided by
Web of Science

Save / Share:
  • A combination of techniques, including AES, SIMS, FTIR, and hydrogen chemisorption, has been used to investigate the activation of nickel ions supported on hydrous titanium oxide (HTO) ion-exchange materials. HTO supports allow metal ions to be loaded via ion exchange such that atomic dispersion is attained in the as-prepared material, even for high metal loadings. The results presented here support earlier work indicating that nickel forms large, 10-20-nm particles during hydrogen reduction of Ni/HTO at temperatures of 300[degree]C of greater. During reduction, these particles become covered by an amorphous film which inhibits catalytic activity. Evidence is presented which supports themore » theory that this film is composed of carbonaceous residue which originates from the organometallic precursors and organic solvents used to synthesize the HTO support. Reduction/oxidation cycles result in oscillations in the nickel surface concentration which are attributed to decoration of the particles by partially reduced TiO[sub x] species, in a manner similar to a strong metal-support interaction (SMSI). This SMSI occurs at temperatures as low as 300[degree]C, well below the temperatures typically required to induce SMSI on crystalline titania supports. 42 refs., 9 figs., 1 tab.« less
  • On the basis of the rate constant per active site determined by pulse surface reaction rate analysis (PSRA), the effect of the strong metal-support interaction (SMSI) on the hydrogenation of adsorbed CO was studied for titania-supported noble metal catalysts. Reduction at 773 K resulted in a drastic decrease in the amount of CO adsorbed on all noble metals examined. The observed suppression of CO chemisorption resulted mainly from SMSI, because the chemisorption ability was restored considerably by heating these catalysts in an O{sub 2} atmosphere and then reducing at 523 K. It was found that the effect of SMSI onmore » the hydrogenation of adsorbed CO was different from one noble metal to another, although its effect on CO chemisorption was common to all titania-supported noble metals. Pt and Pd exhibited a much higher hydrogenation activity in their SMSI state than in their normal state, whereas Rh, Ru, and Ir exhibited almost the same activity in both states. By heating titania-supported Pt and Pd in O{sub 2} and then reducing at 523 K, concomitant with destruction of the SMSI state, the high hydrogenation activity disappeared to near each original value. Subsequent reduction at 773 K again brought these catalysts to the SMSI state, accompanied by an increase in their activity. From these results, a possible cause is discussed for the high activity on Pt and Pd in the SMSI state and for its absence on Rh, Ru, and Ir in the SMSI state.« less
  • Water-gas shift was studied at 663 K and 0.1 MPa over a series of silica-supported magnetite (Fe/sub 3/O/sub 4/) catalysts having magnetite particles from ca. 10 to 160 nm in size. The surface sites on these catalysts were titrated using NO adsorption at 273 K and adsorption from a CO/sub 2//CO gas mixture (CO/sub 2/:CO = 85:15) at 663 K. For these silica-supported catalysts, the water-gas shift turnover frequency, based on NO adsorption for site titration, decreased with decreasing particle size. In contrast, unsupported magnetite did not show this particle size dependence. For the smallest silica-supported magnetite particles, the turnovermore » frequency was three orders of magnitude lower than over unsupported magnetite. The extent of CO and CO/sub 2/ adsorption, per surface site as titrated by NO, was also observed to decrease with decreasing particle size; and, the water-gas shift turnover frequency, based on CO/sub 2//CO adsorption for site titration, is independent of particle size. Thus, while NO adsorption can be used to measure the magnetite surface area of silica-supported samples, the CO/sub 2//CO adsorption uptake is proportional to the number of active sites on the magnetite surface. Compared to unsupported magnetite, the origin of the low catalytic activity of silica-supported magnetite (based on NO adsorption for site titration) is interpreted as being due to the effects of Si/sup 4 +/ substitution into the surface of magnetite, which causes the iron cations at the surface to become electron deficient and coordinatively more saturated with oxygen anions. 2 figures, 1 table.« less
  • Water-gas shift activity measurements at ca. 650 K, nitric oxide chemisorption at 273 K for surface area determination, and Mossbauer spectroscopy were used to study the surface properties of magnetite (Fe/sub 3/O/sub 4/) support on silica. A strong interaction between these two oxides takes place, due to the substitution of Si/sup 4 +/ for tetrahedral Fe/sup 3 +/. This substitution can be described by a core and shell model in which a core of unperturbed Fe/sub 3/O/sub 4/ is surrounded by a Si/sup 4 +/ substituted shell that is ca. 0.5 nm thick. This shell is formed irreversibly during treatmentmore » of silica-supported magnetite in H/sub 2/O-containing environments at ca. 650 K and near atmospheric pressures. While the formation of this thin shell does not significantly diminish the capacity of silica-supported magnetite to chemisorb NO, the apparent turnover frequency for water-gas shift (based on rate measurements and the NO chemisorption uptake) can be reduced by approximately one order of magnitude.« less
  • Ethane hydrogenolysis and carbon monoxide hydrogenation were studied over two niobia (Nb/sub 2/O/sub 5/)-supported nickel catalysts, containing 2 and 10 wt% nickel, which had been reduced in hydrogen at 573 or 773 K for 1 h. Compared to silica-supported nickel catalysts, these samples had lower ethane hydrogenolysis activity but higher CO hydrogenation activity. For some samples a different experimental rate law for ethane hydrogenolysis was observed. In CO hydrogenation, all samples showed a shift in product distribution to hydrocarbons higher than methane, and olefinic products were detected. These observations were attributed to strong metal-support interaction (SMSI). The use of thesemore » chemical probes identified different manifestation of SMSI that depend on crystallite size and reduction treatment. On the basis of these manifestations, a hierarchy consisting of five stages was developed to rank the extent of interaction in Ni/Nb/sub 2/O/sub 5/ catalysts. A mechanism of SMSI was proposed for a physical explanation of this hierarchy.« less