Promotion Effect of CeO2 on Pd/SiO2 Catalyst for Methanol Decomposition.

Imamura, Seiichiro; Yamane, Hideyuki; Kanai, Hiroyoshi; Shibata, Takashi; Utani, Kazunori; Hamada, Kazuhiko

doi:10.1627/jpi.45.187

Cited by 7 publications

(4 citation statements)

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“…Ceria-based catalysts have been widely used in steam reforming of methanol for hydrogen production. [1][2][3][4][5][6][7][8] In these catalysts, ceria not only is used as a support to stabilize the transition metal nanoparticles but also plays some direct role in the catalytic reactions. A detailed characterization of the interactions between methanol and the well-defined singlecrystal ceria surface is an important step toward understanding the chemistry of methanol on ceria-based catalysts.…”

Section: Introductionmentioning

confidence: 99%

“…Ceria-based catalysts have been widely used in steam reforming of methanol for hydrogen production. − In these catalysts, ceria not only is used as a support to stabilize the transition metal nanoparticles but also plays some direct role in the catalytic reactions. A detailed characterization of the interactions between methanol and the well-defined single-crystal ceria surface is an important step toward understanding the chemistry of methanol on ceria-based catalysts. , The adsorption and reaction of oxygenates such as methanol on a metal oxide surface are believed to depend on the redox properties of the oxide as well as on the extent of coordinative unsaturation of the surface metal atoms. , As such, experimental investigations of methanol adsorption on supported unreduced and reduced CeO 2 (111) surfaces have been per-formed. − Recently, we reported a DFT study of methanol adsorption on the CeO 2 (111) surface .…”

Section: Introductionmentioning

confidence: 99%

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Density Functional Theory Study of Methanol Decomposition on the CeO₂(110) Surface

et al. 2008

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Methanol decomposition on the stoichiometric CeO 2 (110) surface has been investigated using density functional theory slab calculations. Three possible initial steps to decompose methanol by breaking one of three bonds (O-H, C-O, and C-H) of methanol were examined. The relative order of thermodynamic stability for the three possible bond scission steps is C-H > O-H > C-O. We further isolated transition states and determined activation energies for each of the bond-breaking modes using the nudged elastic method. The activation barrier for the most favorable dissociation mode, the O-H bond scission, is 0.3 eV on the (110) surface. An even lower activation barrier (<0.1 eV) has been obtained on the CeO 2 (111) surface for the same bondbreaking mode. We also calculated pre-exponential factors based on the harmonic approximation and obtained overall rate constants at 300 and 500 K for all three initial decomposition steps. In contrast to the order of thermodynamic stability, the calculated bond breaking barriers indicated a different favorable bond breaking order: O-H > C-O > C-H. Our results are consistent with experimental observation that methoxy is the dominant surface species after the stoichiometric CeO 2 surface was exposed to methanol. The experimentally observed methanol chemistry was determined by the kinetics of the initial dissociation steps rather than the thermodynamic stability of product states. The surface coverage of methanol was found to affect the relative stability between molecular and dissociative adsorption modes: Dissociative adsorption modes are preferred for methanol coverages up to 0.5 ML but only molecular adsorption was found to be stable at a full monolayer coverage.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Density Functional Theory Study of Methanol Decomposition on the CeO₂(110) Surface

et al. 2008

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“…Ceria has attracted considerable attention over the past few years both as a catalyst support and as a promoter in many heterogeneous catalytic processes such as NO x reduction from automotive emissions − and hydrogen production from methanol. − In particular, efficient production of hydrogen from methanol would have a great impact on the future hydrogen economy. On the other hand, the catalytic role that ceria plays in methanol conversion is still not understood, and insight into the interaction between ceria surfaces and methanol molecules will help us to better understand and elucidate the reactivity and selectivity of ceria-based catalysts.…”

Section: Introductionmentioning

confidence: 99%

Methanol Adsorption on the Clean CeO₂(111) Surface: A Density Functional Theory Study

et al. 2007

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Molecular and dissociative adsorption of methanol at various sites on the stoichiometric CeO 2 (111) surface have been studied using density functional theory periodic calculations. At 0.25 monolayer (ML) coverage, the dissociative adsorption with an adsorption energy of 0.55 eV is slightly favored. The most stable state is the dissociative adsorption of methanol via C-H bond breaking, forming a coadsorbed hydroxymethyl group and hydrogen adatom on two separate O 3C surface sites. The strongest molecular adsorption occurs through an O-Ce 7C connection with an adsorption energy of 0.48 eV. At methanol coverage of 0.5 ML, the dissociative adsorption and the molecular adsorption became competitive. The adsorption energy per methanol molecule for both adsorption modes falls into a narrow range of 0.46-0.55 eV. As methanol coverage increases beyond 0.5 ML, the molecular adsorption becomes more energetically favorable than the dissociative adsorption because of the attractive hydrogen bonding between coadsorbed methanol molecules. At full monolayer, the adsorption energy of molecular adsorption is 0.40 eV per molecule while the adsorption energy for total dissociative adsorption of methanol is only 0.17 eV. The results at different methanol coverages indicate that methanol can adsorb on a defect-free CeO 2 (111) surface, which are also consistent with experimental observations.

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“…A promoter component was ceria, which has oxygen storage action [9][10][11][12][13][14]. Owing to this function, it promotes the action of various precious metals in the reactions in which hydrogen is involved as a reactant or product [15][16][17][18][19] …”

Section: Introductionmentioning

confidence: 99%

Catalytic steam reforming of ethanol to produce hydrogen and acetone

Nishiguchi

Matsumoto

Kanai

et al. 2005

Applied Catalysis A: General

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Promotion Effect of CeO2 on Pd/SiO2 Catalyst for Methanol Decomposition.

Cited by 7 publications

References 1 publication

Density Functional Theory Study of Methanol Decomposition on the CeO₂(110) Surface

Density Functional Theory Study of Methanol Decomposition on the CeO₂(110) Surface

Methanol Adsorption on the Clean CeO₂(111) Surface: A Density Functional Theory Study

Catalytic steam reforming of ethanol to produce hydrogen and acetone

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Promotion Effect of CeO2 on Pd/SiO2 Catalyst for Methanol Decomposition.

Cited by 7 publications

References 1 publication

Density Functional Theory Study of Methanol Decomposition on the CeO2(110) Surface

Density Functional Theory Study of Methanol Decomposition on the CeO2(110) Surface

Methanol Adsorption on the Clean CeO2(111) Surface: A Density Functional Theory Study

Catalytic steam reforming of ethanol to produce hydrogen and acetone

Contact Info

Product

Resources

About

Density Functional Theory Study of Methanol Decomposition on the CeO₂(110) Surface

Density Functional Theory Study of Methanol Decomposition on the CeO₂(110) Surface

Methanol Adsorption on the Clean CeO₂(111) Surface: A Density Functional Theory Study