Skip to main content

Nanostructured H3+x PW12−x Nb x O40 (x = 0–3) Keggin Heteropolyacid Catalysts

Buy Article:

$113.00 plus tax (Refund Policy)

Abstract:

Nanostructured H3+x PW12−x Nb x O40 (x = 0, 1, 2, 3) Keggin heteropolyacid (HPA) catalysts were investigated by scanning tunneling microscopy (STM) and tunneling spectroscopy to probe their redox property and oxidation catalysis. STM image showed that the HPAs formed two-dimensional well-ordered monolayer arrays on graphite surface. In tunneling spectra of the HPAs deposited on graphite, they exhibited a distinctive current–voltage behavior referred to as negative differential resistance (NDR). NDR peak voltage measured atop HPA molecule was then correlated with reduction potential and absorption edge energy determined by electrochemical method and UV-visible spectroscopy, respectively. It was revealed that NDR peak voltage of the HPAs appeared at less negative voltage with increasing reduction potential and with decreasing absorption edge energy. In order to correlate NDR peak voltage of H3+x PW12−x Nb x O40 Keggin HPAs with oxidation catalysis, oxidative dehydrogenation of isobutyraldehyde to methacrolein was carried out as a model reaction. NDR peak voltage of the HPAs appeared at less negative voltage with increasing yield for methacrolein.

Keywords: HETEROPOLYACID; KEGGIN HETEROPOLYACID NANOCATALYSTS; NEGATIVE DIFFERENTIAL RESISTANCE; REDOX PROPERTY; SCANNING TUNNELING MICROSCOPY; TUNNELING SPECTROSCOPY

Document Type: Research Article

DOI: https://doi.org/10.1166/jnn.2011.4711

Publication date: 2011-09-01

More about this publication?
  • Journal for Nanoscience and Nanotechnology (JNN) is an international and multidisciplinary peer-reviewed journal with a wide-ranging coverage, consolidating research activities in all areas of nanoscience and nanotechnology into a single and unique reference source. JNN is the first cross-disciplinary journal to publish original full research articles, rapid communications of important new scientific and technological findings, timely state-of-the-art reviews with author's photo and short biography, and current research news encompassing the fundamental and applied research in all disciplines of science, engineering and medicine.
  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • Terms & Conditions
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more