Preparation and characterization of Cu-Ce-La mixed oxide as water-gas shift catalyst for fuel cells application

Zhi, Keduan; Liu, Quansheng; Zhao, Ruigang; He, Rong; Zhang, Lifeng

doi:10.1016/s1002-0721(08)60133-7

Cited by 23 publications

(9 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a part of industrial steam methane reforming (SMR) processes, the water gas shift (WGS) reaction, in which CO reacts with water steam to produce hydrogen and CO 2 , has become a subject of increasing interest. − The design and development of more efficient catalysts to enhance the production process have become essential to meet the demand for hydrogen, which has risen rapidly in recent years. The majority of the current research efforts on the WGS reaction is to use supported precious metals as catalysts to produce a high purity of hydrogen at temperatures lower than the temperature range used in industrial SMR processes. , In contrast, a commercial scale WGS reaction utilizes mostly iron-based catalysts. , In general, a WGS process consists of two stages.…”

Section: Introductionmentioning

confidence: 99%

Density Functional Theory Study of Water Dissociative Chemisorption on the Fe₃O₄(111) Surface

et al. 2010

View full text Add to dashboard Cite

Water dissociative chemisorption on the Fe oct-tet1 -terminated Fe 3 O 4 (111) surface was studied using periodic density functional theory (DFT) at both low and high water coverage. The active sites and adsorption patterns were identified, and the dissociation pathways and energetics were calculated. It was found that water can undergo dissociative chemisorption to form a surface hydroxyl group and a H atom with a favorable thermochemical energy and a moderate activation barrier at low coverage. This reaction can be readily catalyzed by water molecules around the active sites. We found that direct breakup of the hydroxyl group into H and O adatoms on the surface is energetically difficult and higher water coverage has an only modest effect on catalyzing the reaction. Our results are consistent with the kinetic and isotope exchange experiments.

show abstract

Section: Introductionmentioning

confidence: 99%

Density Functional Theory Study of Water Dissociative Chemisorption on the Fe₃O₄(111) Surface

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Water gas shift (WGS) reaction (CO + H 2 O = CO 2 + H 2 ) is an important industry process for hydrogen production and CO removal and has been widely used for ammonia 1,2 and methanol syntheses, [3][4][5] and for PEM fuel cell applications. [6][7][8] For high temperature WGS reaction, Fe 3 O 4 catalyst is promoted with Cu to improve the catalytic activity. 9,10 It has been found in several recent experiments that Cu atoms are evenly dispersed in solid solutions in the freshly prepared catalyst but segregated out from the solid to form Cu clusters on the catalyst surfaces at the operating conditions of WGS reaction.…”

Section: Introductionmentioning

confidence: 99%

A first principles study of water dissociation on small copper clusters

Chen

Zhang

et al. 2010

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Water dissociation on copper is one of the rate-limiting steps in the water-gas-shift (WGS) reaction. Copper atoms dispersed evenly from freshly made catalyst segregate to form clusters under the WGS operating conditions. Using density functional theory, we have examined water adsorption and dissociation on the smallest stable 3-dimensional copper cluster, Cu(7). Water molecules are adsorbed on the cluster sequentially until full saturation at which no direct water-copper contact is sterically possible. The adsorption is driven mainly by the overlap between the p-orbital of O atom occupied by the lone pair and the 3d-orbitals of copper, from which a fractional charge is promoted to the 4s-orbital to accommodate the charge transfer from water. Water dissociation on the Cu(7) cluster was investigated at both low and high water coverage. It was found that water dissociation into OH and H is exothermic but is inherently a high temperature process at low coverage. At high coverage, the reaction becomes more exothermic with fast kinetics. In both cases, water can catalyze the reaction. It was found that direct dissociation of the OH species is endothermic with a significantly higher barrier at both low and high coverage. However, the OH species can readily react with another adjacent hydroxyl group to form an O adatom and water molecule. Our studies indicate that the basic chemical properties of water dissociative chemisorption may not change significantly with the size of small copper clusters. Similarities between water dissociation on copper clusters and on copper crystalline surfaces are discussed.

show abstract

“…It has been broadly reported that the solubility of copper in the ceria lattice heavily depend on the preparation method and calcination conditions [14,34,35]. For further clarification the lattice constants of ceria were estimated and presented in Table 2.…”

Section: Xrdmentioning

confidence: 99%

WGS and CO-PrOx reactions using gold promoted copper-ceria catalysts: “Bulk CuO CeO2 vs. CuO CeO2/Al2O3 with low mixed oxide content”

Reina

Ivanova

Laguna

et al. 2016

Applied Catalysis B: Environmental

View full text Add to dashboard Cite

A copper-ceria bulk catalyst has been compared to a series of catalysts designed according to the as called "supported approach", corresponding to the dispersion of low content mixed copper-ceria oxide on alumina matrix. The principal characteristics of both types of catalysts are contemplated and the differences in their electronic and redox properties discussed in details. As a plus, the gold metal promotion of the catalysts is also envisaged. The advantages of the systems in the CO clean up reactions, WGS and CO-PrOx are commented. While the WGS activity appears to be ruled especially by the Cu/Ce surface to volume ratio, the CO-PrOx reaction is governed by the CuO loading. Gold addition provides benefits only at the low temperature WGS regime. Very importantly, the supported systems are always superior to the bulk configuration in terms of specific activity, a key factor from the catalyst's design perspective.

show abstract

Preparation and characterization of Cu-Ce-La mixed oxide as water-gas shift catalyst for fuel cells application

Cited by 23 publications

References 17 publications

Density Functional Theory Study of Water Dissociative Chemisorption on the Fe₃O₄(111) Surface

Density Functional Theory Study of Water Dissociative Chemisorption on the Fe₃O₄(111) Surface

A first principles study of water dissociation on small copper clusters

WGS and CO-PrOx reactions using gold promoted copper-ceria catalysts: “Bulk CuO CeO2 vs. CuO CeO2/Al2O3 with low mixed oxide content”

Contact Info

Product

Resources

About

Preparation and characterization of Cu-Ce-La mixed oxide as water-gas shift catalyst for fuel cells application

Cited by 23 publications

References 17 publications

Density Functional Theory Study of Water Dissociative Chemisorption on the Fe3O4(111) Surface

Density Functional Theory Study of Water Dissociative Chemisorption on the Fe3O4(111) Surface

A first principles study of water dissociation on small copper clusters

WGS and CO-PrOx reactions using gold promoted copper-ceria catalysts: “Bulk CuO CeO2 vs. CuO CeO2/Al2O3 with low mixed oxide content”

Contact Info

Product

Resources

About

Density Functional Theory Study of Water Dissociative Chemisorption on the Fe₃O₄(111) Surface

Density Functional Theory Study of Water Dissociative Chemisorption on the Fe₃O₄(111) Surface