Analysis of reaction mechanisms and kinetics of preferential CO oxidation over Au/γ-Al2O3

Davran-Candan, Tuğba; Demir, M. Utku; Yıldırım, Ramazan

doi:10.1007/s11144-011-0370-8

Cited by 10 publications

(6 citation statements)

References 32 publications

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“…As concerns the kinetics, several models have been proposed for the PROX reaction over CuO xCeO 2 [25][26][27][28][29][30][31][32]. The formulation of adequate kinetic models is a key step on designing and scaling up of PROX units [33], thus being fundamental for the practical applications of this H 2 cleaning technology.…”

Section:  mentioning

confidence: 99%

Gold supported on CuOx/CeO2 catalyst for the purification of hydrogen by the CO preferential oxidation reaction (PROX)

Laguna

Hernández

Arzamendi

et al. 2014

Fuel

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Hydrogen produced from the conversion of hydrocarbons or alcohols contains variable amounts of CO that should be removed for some applications such as feeding lowtemperature polymer electrolyte membrane fuel cells (PEMFCs). The CO preferential oxidation reaction (PROX) is particularly well-suited for hydrogen purification for portable and on-board applications. In this work, the synthesis and characterization by XRF, BET, XRD, Raman spectroscopy and H 2 -TPR of a gold catalyst supported on a copper-cerium mixed oxide (AuCeCu) for the PROX reaction are presented. The comparison of this catalyst with the copper-cerium mixed oxide (CeCu) revealed that the experimental procedure used for the deposition of gold gave rise to the loss of reducible material by copper lixiviation. However, the AuCeCu solid was more active for CO oxidation at low temperature. A kinetic study has been carried over the AuCeCu catalyst for the PROX reaction and compared with that of the CeCu catalyst. The main difference between the models affected the contribution of the CO adsorption term. This fact may be related to the surface electronic activity produced by the interaction of the cationic species in the AuCeCu solid, able to create more active sites for the CO adsorption and activation in the presence of gold.

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Section:  mentioning

confidence: 99%

Gold supported on CuOx/CeO2 catalyst for the purification of hydrogen by the CO preferential oxidation reaction (PROX)

Laguna

Hernández

Arzamendi

et al. 2014

Fuel

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“…Concerning the kinetics of the Cu/CuO-CeO 2 [33][34][35][36][37] and Aucatalyzed [38][39][40][41][42][43][44] CO-PROX reactions, it has been shown that copper-catalyzed reactions exhibited high values of apparent activation energies (Ea), from 50 to 100 kJ/mol, whereas goldcatalyzed reactions exhibited much lower Ea with values of 20-40 kJ/mol. Besides, for supported Au catalysts, the partial reaction orders of both CO (a) and O 2 (b) for supported Au are positive.…”

Section: Introductionmentioning

confidence: 99%

Promoting effect of AuCu alloying on Au-Cu/CeO2-catalyzed CO oxidation: A combined kinetic and in situ DRIFTS study

Liao

Liu

Chu

et al. 2020

Journal of Catalysis

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Reduced Au-Cu/CeO 2 catalysts (Cu/Au = 1, 3) are more efficient towards the preferential oxidation of CO (PROX) than their calcined counterparts. They exhibit lower activation energies and CO partial reaction orders (a CO), and even more interestingly, significantly higher O 2 partial reaction orders (b O2). For the stoichiometric composition in particular (Au 1 Cu 1 /CeO 2-R), the partial pressure of oxygen has a higher impact on the reaction rate than the partial pressure of CO (b O2 > a CO), which is unprecedented in low temperature catalysis involving gold and a reducible oxide support. DRIFTS studies further show (1) that Au 1 Cu 1 /CeO 2-R contains electron-deficient, alloyed Cu atoms (Au-Cu +) and (2) that the formation of CO 2 is enhanced by the preadsorption of O 2 rather than the preadsorption of CO. This suggests that CO oxidation proceeds via a Langmuir-Hinshelwood-type, bifunctional mechanism, involving CO adsorbed on Au 0 sites and oxygen adsorbed on electron-deficient, gold-alloyed copper sites. This alloy-mediated oxygen activation could be the key to the superior PROX activity of Au 1 Cu 1 /CeO 2-R.

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“…[29] The presence of H 2 in the feed usually enhanced the CO conversion, even though it sometimes negatively affected the selectivity (which is not a serious problem for this system as explained in the Introduction). [30] Although the presence and absence of H 2 made some difference in the catalytic activity, the change in H 2 concentration did not significantly affect CO conversion because H 2 was almost always in excess when present.…”

Section: Review Of Publications From 2000 To 2012mentioning

confidence: 94%

Knowledge Extraction from Catalysis of the Past: A Case of Selective CO Oxidation over Noble Metal Catalysts between 2000 and 2012

Günay

Yıldırım

2013

ChemCatChem

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The objective of this work is to demonstrate that some valuable knowledge can be extracted from past publications by using various data mining tools so that the continuously growing experience accumulated in the literature over the years can be used in a more effective manner. Selective CO oxidation over noble metal catalysts is chosen as a case to test the validity of this approach because a considerable number of papers were published on this subject in the last decade. Thus, 249 papers published in the last 12 years have been inspected, 80 of which were used to form a database containing 5610 data points. First, the database was analyzed by using decision tree classification to determine the conditions that lead to high CO conversion. Then, the relative importance of various catalyst preparation and operational variables for CO conversion were determined by using artificial neural networks. Finally, the database was separated into smaller clusters by using a genetic algorithm‐based clustering technique, and the data in each cluster was modeled by artificial neural networks to predict the effects of individual catalyst preparation and operational conditions on the catalytic activity. All these analyses were effective in the extraction of knowledge from the literature and the deduction of some useful trends, rules, and correlations, which are otherwise not easily comprehensible.

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Analysis of reaction mechanisms and kinetics of preferential CO oxidation over Au/γ-Al2O3

Cited by 10 publications

References 32 publications

Gold supported on CuOx/CeO2 catalyst for the purification of hydrogen by the CO preferential oxidation reaction (PROX)

Gold supported on CuOx/CeO2 catalyst for the purification of hydrogen by the CO preferential oxidation reaction (PROX)

Promoting effect of AuCu alloying on Au-Cu/CeO2-catalyzed CO oxidation: A combined kinetic and in situ DRIFTS study

Knowledge Extraction from Catalysis of the Past: A Case of Selective CO Oxidation over Noble Metal Catalysts between 2000 and 2012

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