Reactivity of carbon monoxide on vanadium-promoted rhodium catalysts as studied with transient techniques

T. Koerts, W.J.J. Welters, R.A. Santen, van

Research output: Contribution to journalArticleAcademicpeer-review

40 Citations (Scopus)
70 Downloads (Pure)

Abstract

The effect of vanadium promotion on the kinetics of CO methanation on silica-based rhodium catalysts was probed. Transient model experiments employing temperature-programmed surface reaction spectroscopy and pulse surface reaction rate analysis were used to unravel changes in rates of elementary reaction steps. CO dissociation is the rate-limiting step in the overall methanation reaction. The rate of CO dissociation is found to be enhanced by vanadium. The activation energy is lowered from 90 kJ/mol for Rh/SiO2 to 65 kJ/mol for the promoted catalyst. The activation energy for CO dissociation is not dependent on the hydrogen partial pressure, while it is a strong function of the CO surface coverage. CO adsorption at temperatures above 250°C results in very reactive surface carbonaceous intermediates. Even at -15°C methane formation was observed upon hydrogenation. This reactive surface carbon can be incorporated in higher hydrocarbons. This process is favoured by vanadium promotion.
Original languageEnglish
Pages (from-to)1-12
Number of pages12
JournalJournal of Catalysis
Volume134
Issue number1
DOIs
Publication statusPublished - 1992

Fingerprint

Dive into the research topics of 'Reactivity of carbon monoxide on vanadium-promoted rhodium catalysts as studied with transient techniques'. Together they form a unique fingerprint.

Cite this