Oxidative coupling of methane over NbO (p-type) and Nb2O5 (n-type) semiconductor materials

Erarslanoglu Y., Onal I., Dogu T., Senkan S.

CATALYSIS LETTERS, vol.38, pp.215-218, 1996 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 38
  • Publication Date: 1996
  • Doi Number: 10.1007/bf00806571
  • Journal Name: CATALYSIS LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.215-218
  • Middle East Technical University Affiliated: Yes

Abstract

Oxidative coupling of methane to higher hydrocarbons was investigated using two types of semiconductor catalysts, NbO (p-type) and Nb2O5 (n-type) at 1 atm pressure. The ratio of methane partial pressure to oxygen partial pressure was changed from 2 to 112 and the temperature was kept at 1023 K in the experiments conducted in a cofeed mode. The results indicated a strong correlation between C-2+ selectivity performance and the electronic properties of the catalyst in terms of p- vs. n-type conductivity. The p-type semiconductor catalyst, NbO, had a larger selectivity (e.g. 95.92%) over the n-type Nb2O5 catalyst (23.08%) both at the same methane conversion of 0.64%. Catalyst characterization via X-ray diffraction, TGA and reaction studies indicated that NbO was transformed to Nb2O5 during the course of the reaction which limits catalyst life.