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Title: Manganese Oxide Nanoarray-Based Monolithic Catalysts: Tunable Morphology and High Efficiency for CO Oxidation

In this work, a generic one-pot hydrothermal synthesis route has been successfully designed and utilized to in situ grow uniform manganese oxide nanorods and nanowires onto the cordierite honeycomb monolithic substrates, forming a series of nanoarray-based monolithic catalysts. During the synthesis process, three types of potassium salt oxidants have been used with different reduction potentials, i.e., K 2Cr 2O 7, KClO 3, and K 2S 2O 8, denoted as HM-DCM, HM-PCR, and HM-PSF, respectively. The different reduction potentials of the manganese source (Mn 2+) and oxidants induced the formation of manganese oxide nanoarrays with different morphology, surface area, and reactivity of carbon monoxide (CO) oxidation. K 2Cr 2O 7 and KClO 3 can induce sharp and long nanowires with slow growth rates due to their low reduction potentials. In comparison, the nanoarrays of HM-PSF presented shorter nanorods but displayed an efficient 90% CO oxidation conversion at 200 °C (T90) without noble-metal loading. Reducibility tests for the three monolithic catalysts by hydrogen temperature-programmed reduction revealed an activation energy order of HM-PSF > HM-DCM > HM-PCR for CO oxidation. The characterizations of oxygen temperature-programmed desorption and X-ray photoelectron spectroscopy indicated the abundant surface-adsorbed oxygen and lattice oxygen contributing to the superior reactivitymore » of HM-PSF. Finally, the straightforward synthetic process showed a scalable, low-cost, and template-free method to fabricate manganese oxide nanoarray monolithic catalysts for exhaust treatment.« less
Authors:
 [1] ;  [1] ;  [2] ;  [2] ;  [1] ;  [1] ;  [1] ;  [2] ;  [3]
  1. Univ. of Connecticut, Storrs, CT (United States). Department of Chemistry
  2. Univ. of Connecticut, Storrs, CT (United States). Department of Chemistry. Department of Materials Science and Engineering & Institute of Materials Science
  3. Univ. of Connecticut, Storrs, CT (United States). Department of Chemistry and Department of Materials Science and Engineering & Institute of Materials Science
Publication Date:
Grant/Contract Number:
EE0006854
Type:
Accepted Manuscript
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 8; Journal Issue: 12; Journal ID: ISSN 1944-8244
Publisher:
American Chemical Society (ACS)
Research Org:
Univ. of Connecticut, Storrs, CT (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; array; CO oxidation; manganese oxide; monolithic catalysts; nanorod
OSTI Identifier:
1430244