Preferential oxidation of carbon monoxide with Pt/Fe monolithic catalysts: interactions between external transport and the reverse water-gas-shift reaction

Roberts, George W.; Chin, Paul; Sun, Xiaolei; Spivey, James J.

doi:10.1016/j.apcatb.2003.07.002

Cited by 77 publications

(38 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Above 120 ºC the selectivity decreases with the temperature. This result is in good agreement with previous works and is associated to the presence of the H 2 oxidation and the WGS or R-WGS reactions [12,54], which are more evident at high temperatures. In a recent kinetic study performed on a Au/Ce-Fe catalyst [55], we established that the CO oxidation reaction present a lower specific activation energy (50 kJ/mol) than that of the H 2 oxidation (66.9 kJ/mol), being this fact the reason because the selectivity decreases when the temperature increases.…”

Section: Catalytic Activitysupporting

confidence: 82%

Fe-doped ceria solids synthesized by the microemulsion method for CO oxidation reactions

Laguna

Centeno

Boutonnet

et al. 2011

Applied Catalysis B: Environmental

170

126

View full text Add to dashboard Cite

A series of Ce-Fe mixed oxides as well as the pure oxides were synthesized by the microemulsions method. The solid solution formation was established for all the Fedoped systems and only a hardly noticeable segregation of α-Fe 2 O 3 was appreciated for the solid with the maximum iron content (50 Fe atomic%). The oxygen exchange is improved for all the Fe-doped systems; however the 10 Fe atomic% appears as the optimal iron content for achieving the maximum oxygen vacancies concentration and the higher reducibility efficiency. The CO oxidation (TOX, PROX) is especially achieved for the solids with the lower iron contents but with a superior oxygen vacancies proportion. These Ce-Fe systems prepared from microemulsions are very attractive to be considered as supports for depositing active phases capable of enhancing oxygen exchange ability of the whole system, allowing higher CO oxidation abilities.

show abstract

Section: Catalytic Activitysupporting

confidence: 82%

Fe-doped ceria solids synthesized by the microemulsion method for CO oxidation reactions

Laguna

Centeno

Boutonnet

et al. 2011

Applied Catalysis B: Environmental

170

126

View full text Add to dashboard Cite

show abstract

“…A similar behaviour of the selectivities increasing with the space velocity for the MR150 was observed by Roberts et al [27] in their study about Pt/Fe monolithic catalysts for the PROX reaction. They established that the CO selectivity increased with increasing the space velocity while the CO and O 2 conversions decreased and proposed that the R-WGS reaction was more important at low space velocities.…”

Section: Effect Of the Space Velocity Over The Microreactorssupporting

confidence: 59%

Microreactors technology for hydrogen purification: Effect of the catalytic layer thickness on CuO /CeO2-coated microchannel reactors for the PROX reaction

Laguna

González‐Castaño

Odriozola

2015

Chemical Engineering Journal

View full text Add to dashboard Cite

Two blocks of microreactors composed by 100 microchannels and coated, respectively, with 150 and 300 mg of a CuO x /CeO 2 catalyst, were prepared and tested in the preferential oxidation of CO in presence of H 2 (PROX). The deposition of different amount of catalyst resulted in different catalytic layer thicknesses thus modifying the catalytic performances of the microreactor. The evaluation of the main reaction variables (the space velocity, the O 2 -to-CO ratio and the presence of H 2 O and/or CO 2 in the stream) was performed over both microreactors and compared to that of the parent powder catalyst. The least loaded microreactor, with a coating thickness around 10 µm, presented the highest CO conversion and selectivity levels at temperatures below 160 ºC.This result evidences i) the improvement of the catalytic performances got by the structuration of the powder catalyst and ii) the importance of the selection of the adequate thickness of the catalytic layer on the microreactor, which have not to exceed and optimal value. An adequate coating thickness allows minimizing the mass and heat transport limitations, thus resulting in the enhancement of the catalytic performance during the PROX reaction.

show abstract

“…The exothermicity of the CO and H 2 oxidation reactions (-283 and -242 kJ·mol [ 25], in which the r-WGS reaction occurrence was analysed in an adiabatic monolith reactor during the CO-PROX. In this work it was observed that the complete conversion of O 2 generates an important increase of the temperature until 300 ºC for an inlet temperature of 170 ºC.…”

Section: Methodsmentioning

confidence: 99%

Influence of the O2/CO ratio and the presence of H2O and CO2 in the feed-stream during the preferential oxidation of CO (PROX) over a CuOx/CeO2-coated microchannel reactor

et al. 2013

View full text Add to dashboard Cite

The catalytic performance of a CuO x /CeO 2 powder catalyst and that of a microchannel reactor or microreactor (MR) coated with the same solid were determined and compared. The catalytic activity measurements were carried out with varying O 2 /CO molar ratios in the feed-stream. In addition, the influence of the presence of CO 2 and H 2 O in the reaction mixture was studied. Some discrepancies were observed between the performances of the powder catalyst and the MR depending on the O 2 /CO ratio. The MR presented a very good performance with a superior selectivity for CO conversion.This behaviour was due to a more efficient heat removal in the case of the MR that inhibited the H 2 oxidation reaction and the r-WGS. The isothermicity of the microreactor during the process was demonstrated through the monitoring of the MR inlet and outlet temperatures.Concerning the presence of CO 2 or H 2 O in the feed-stream, both compounds gave rise to a decrease of the CO conversion. The negative effect on the catalytic performance was more marked when both compounds were fed together, although the principal inhibitor effect was associated to the CO 2 . This seems to be related with the formation of stable carbonates at the catalyst surface.

show abstract

Preferential oxidation of carbon monoxide with Pt/Fe monolithic catalysts: interactions between external transport and the reverse water-gas-shift reaction

Cited by 77 publications

References 14 publications

Fe-doped ceria solids synthesized by the microemulsion method for CO oxidation reactions

Fe-doped ceria solids synthesized by the microemulsion method for CO oxidation reactions

Microreactors technology for hydrogen purification: Effect of the catalytic layer thickness on CuO /CeO2-coated microchannel reactors for the PROX reaction

Influence of the O2/CO ratio and the presence of H2O and CO2 in the feed-stream during the preferential oxidation of CO (PROX) over a CuOx/CeO2-coated microchannel reactor

Contact Info

Product

Resources

About