Facilitating role of Pd for hydrogen, oxygen and water adsorption/desorption processes from bulk CeO2 and CeO2/γ- Al2O3

被引：19

作者：

Kaya, Deniz ^{[1
]}

Singh, Dheerendra ^{[1
]}

Kincal, Serkan ^{[1
]}

Uner, Deniz ^{[1
]}

机构：

[1] Middle East Tech Univ, Dept Chem Engn, Fac Engn, TR-06800 Ankara, Turkey

来源：

CATALYSIS TODAY | 2019年 / 323卷

关键词：

CeO2; Pd; Spillover; Reverse spillover; Differential heat of adsorption; CERIA; TEMPERATURE; SUPPORT; CO2; COMBUSTION; CHEMISTRY; CATALYSIS; VACANCIES; PD/CERIA; ENERGY;

D O I：

10.1016/j.cattod.2018.04.063

中图分类号：

O69 [应用化学];

学科分类号：

081704 ;

摘要：

The enhanced rates of reduction and re-oxidation of ceria in the presence of Pd, was investigated on both bulk ceria as well as ceria deposited over gamma-Al2O3. Pd addition and surface area enhancement by gamma-Al2O3 decreased the reduction temperature of CeO2 as monitored by temperature programmed reduction (TPR) in H-2. Temperature programmed oxidation (TPO) and temperature programmed thermal decomposition (TPtD) measurements revealed similar results of more favorable temperatures of oxidation and thermal decomposition. Pd assisted oxygen removal from CeO2 through a reverse spillover process as monitored by the temperature programmed thermal decomposition experiments was evident from the decomposition temperature of PdO to Pd. The adsorption microcalorimetry measurements at 323 K revealed that hydrogen adsorption initiated over Pd extends to CeO2 by migration (or spillover). Oxygen adsorption, however, was restricted to Pd surface at 323 K. Also at the same temperature, initial H2O adsorption was accompanied by very high heats at low coverages indicating surface oxidation. At higher pressures, H2O adsorption extended to coverages representative of the monolayer over.-Al2O3, the heats of adsorption measured at these high coverages corresponded to water condensation.

引用

页码：141 / 147

页数：7

共 36 条

[1] Thermochemical hydrogen production from a two-step solar-driven water-splitting cycle based on cerium oxides [J].

Abanades, Stephane ;

Flamant, Gilles .

SOLAR ENERGY, 2006, 80 (12) :1611-1623

[2]

[Anonymous], 1984, Kinetics of Heterogeneous Catalytic Reactions

[3] Electronic structure and oxygen vacancies in PdO and ZnO: validation of DFT models [J].

Bruska, Marta Kinga ;

Czekaj, Izabela ;

Delley, Bernard ;

Mantzaras, John ;

Wokaun, Alexander .

PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2011, 13 (35) :15947-15954

[4] Chemistry - Oxygen vacancies and catalysis on ceria surfaces [J].

Campbell, CT ;

Peden, CHF .

SCIENCE, 2005, 309 (5735) :713-714

[5]

Cargnello M, 2012, SCIENCE, V337, P713, DOI [10.1126/science.1222887, 10.1126/science.1223488]

[6] High-Flux Solar-Driven Thermochemical Dissociation of CO2 and H2O Using Nonstoichiometric Ceria [J].

Chueh, William C. ;

Falter, Christoph ;

Abbott, Mandy ;

Scipio, Danien ;

Furler, Philipp ;

Haile, Sossina M. ;

Steinfeld, Aldo .

SCIENCE, 2010, 330 (6012) :1797-1801

[7] A thermochemical study of ceria: exploiting an old material for new modes of energy conversion and CO2 mitigation [J].

Chueh, William C. ;

Haile, Sossina M. .

PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 2010, 368 (1923) :3269-3294

[8] Effect of ceria structure on oxygen migration for Rh/ceria catalysts [J].

Cordatos, H ;

Bunluesin, T ;

Stubenrauch, J ;

Vohs, JM ;

Gorte, RJ .

JOURNAL OF PHYSICAL CHEMISTRY, 1996, 100 (02) :785-789

[9]

deB Darwent B., 1970, Bond Dissociation Energies In Simple Molecules

[10] Electron localization determines defect formation on ceria substrates [J].

Esch, F ;

Fabris, S ;

Zhou, L ;

Montini, T ;

Africh, C ;

Fornasiero, P ;

Comelli, G ;

Rosei, R .

SCIENCE, 2005, 309 (5735) :752-755

← 1 2 3 4 →