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

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

doi:10.1016/0021-9517(92)90204-U

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

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

Inorganic Materials & Catalysis

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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 language	English
Pages (from-to)	1-12
Number of pages	12
Journal	Journal of Catalysis
Volume	134
Issue number	1
DOIs	https://doi.org/10.1016/0021-9517(92)90204-U
Publication status	Published - 1992

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title = "Reactivity of carbon monoxide on vanadium-promoted rhodium catalysts as studied with transient techniques",

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.",

author = "T. Koerts and W.J.J. Welters and {Santen, van}, R.A.",

year = "1992",

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T1 - Reactivity of carbon monoxide on vanadium-promoted rhodium catalysts as studied with transient techniques

AU - Koerts, T.

AU - Welters, W.J.J.

AU - Santen, van, R.A.

PY - 1992

Y1 - 1992

N2 - 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.

AB - 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.

U2 - 10.1016/0021-9517(92)90204-U

DO - 10.1016/0021-9517(92)90204-U

M3 - Article

SN - 0021-9517

VL - 134

SP - 1

EP - 12

JO - Journal of Catalysis

JF - Journal of Catalysis

IS - 1

ER -

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

Abstract

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