skip to main content

DOE PAGESDOE PAGES

Title: Influence of dioxygen on the promotional effect of Bi during Pt-catalyzed oxidation of 1,6-hexanediol

In this study, a series of carbon-supported, Bi-promoted Pt catalysts with various Bi/Pt atomic ratios was prepared by selectively depositing Bi on Pt nanoparticles. The catalysts were evaluated for 1,6-hexanediol oxidation activity in aqueous solvent under different dioxygen pressures. The rate of diol oxidation on the basis of Pt loading over a Bi-promoted catalyst was 3 times faster than that of an unpromoted Pt catalyst under 0.02 MPa of O 2, whereas the unpromoted catalyst was more active than the promoted catalyst under 1 MPa of O 2. After liquid-phase catalyst pretreatment and 1,6-hexanediol oxidation, migration of Bi on the carbon support was observed. The reaction order in O 2 was 0 over Bi-promoted Pt/C in comparison to 0.75 over unpromoted Pt/C in the range of 0.02–0.2 MPa of O 2. Under low O 2 pressure, rate measurements in D 2O instead of H 2O solvent revealed a moderate kinetic isotope effect (rate H2O/rate D2O) on 1,6-hexanediol oxidation over Pt/C (KIE = 1.4), whereas a negligible effect was observed on Bi-Pt/C (KIE = 0.9), indicating that the promotional effect of Bi could be related to the formation of surface hydroxyl groups from the reaction of dioxygen and water. No significantmore » change in product distribution or catalyst stability was observed with Bi promotion, regardless of the dioxygen pressure.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [2] ;  [1]
  1. Univ. of Virginia, Charlottesville, VA (United States)
  2. Univ. of New Mexico, Albuquerque, NM (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
ACS Catalysis
Additional Journal Information:
Journal Volume: 6; Journal Issue: 7; Journal ID: ISSN 2155-5435
Publisher:
American Chemical Society
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; alcohol oxidation; Bi; catalyst restructuring; dioxygen pressure; heterogeneous catalysts; isotope effect; promotional effect; Pt
OSTI Identifier:
1261533