Pd as a reduction promoter for TiO2: Oxygen and hydrogen transport at 2D and 3D Pd interfaces with TiO2 monitored by TPR, operando 1H NMR and CO oxidation studies

Yarar, Melis
Bouzani, Asmae
Üner, Deniz
Ambient temperature reduction of TiO2 surface was observed through hydrogen spillover from Pd nanoparticles with a hydrogen consumption stoichiometry of 1.4 H2:Pd up to ≤2 wt%Pd loading. This behavior was attributed to the formation of nanoparticles exhibiting 2D behavior for ≤2 wt%Pd loading. The 2D behavior of Pd nanoparticles were further confirmed from the relative abundance of metallic Pd in 3D, deduced from hydrogen stoichiometry of β-PdHx. EPR revealed oxygen vacancy formation, operando NMR revealed facile hydrogen spillover, and CO oxidation reaction rates systematically increased for Pd ≤ 2 wt%, indicating facile exchange of hydrogen and oxygen at 2D Pd/TiO2 interfaces.
Catalysis Communications


Nanoalumina-supported rhodium(0) nanoparticles as catalyst in hydrogen generation from the methanolysis of ammonia borane
Ozhava, Derya; Özkar, Saim (2017-10-01)
Rhodium(0) nanoparticles were in situ formed from the reduction of rhodium(II) octanoate and supported on the surface of nanoalumina yielding Rh(0)/nanoAl(2)O(3) which is highly active catalyst in hydrogen generation from the methanolysis of ammonia borane at room temperature. The kinetics of nanoparticle formation can be followed just by monitoring the volume of hydrogen gas evolved from the methanolysis of ammonia borane. The evaluation of the kinetic data gives valuable insights to the slow, continuous n...
Adsorption of water and ammonia on TiO2-anatase cluster models
Önal, Işık; Senkan, Selim (2006-06-15)
Density functional theory (DFT) calculations performed at B3LYP/6-31G** level are employed to study water and ammonia adsorption and dissociation on (101) and (001) TiO2 anatase surfaces both represented by totally fixed and partially relaxed Ti2O9H10 cluster models. PM3 semiempirical calculations were also conducted both on Ti2O9H10 and Ti9O33H30 clusters in order to assess the effect of cluster size. Following dissociation, the adsorption of H2O and NH3 by H-bonding on previously H2O and NH3 dissociated s...
Vulcan-Supported Pt Electrocatalysts for PEMFCs Prepared using Supercritical Carbon Dioxide Deposition
Bayrakceken, Ayse; Smirnova, Alevtina; Kitkamthorn, Usanee; Aindow, Mark; Tuerker, Lemi; Eroğlu, İnci; ERKEY, CAN (Informa UK Limited, 2009-01-01)
In this study, supercritical carbon dioxide (scCO(2)) deposition was used to prepare vulcan-supported Pt (Pt/Vulcan) electrocatalysts for proton exchange membrane fuel cells (PEMFCs), and the effects of process variables on the properties of the electrocatalysts were investigated. The two different methods used to reduce the organometallic precursor were thermal reduction in nitrogen at atmospheric pressure and thermal reduction in scCO(2). In the former method, the maximum Pt loading achieved was 9%, and t...
TL and OSL studies on gallium sulfide (GaS) single crystals
Isik, M.; YÜKSEL, MEHMET; TOPAKSU, MUSTAFA; Hasanlı, Nızamı (Elsevier BV, 2020-09-01)
Gallium sulfide (GaS) single crystals were investigated using thermoluminescence (TL) and optically stimulated luminescence (OSL) measurements. TL experiments performed in the room temperature (RT)-450 °C range presented a glow curve consisting in six single discrete peaks. Analyses of TL glow curve by computerized glow curve deconvolution method showed that the trapping centers responsible for peaks are located at 0.98, 1.09, 1.15, 1.76, 1.87 and 1.90 eV. The order of kinetics found between 1 and 2 indicat...
DFT investigation of high temperature water gas shift reaction on chromium-iron mixed oxide catalyst
Yalcin, Ozgen; Önal, Işık (2014-11-20)
As part of high temperature water gas shift reaction mechanism, CO adsorption and H2O adsorption on Fe3O4 (111) and chromium atom substituted Fe3O4 (111) slab surfaces are investigated by means of periodic DFT approach using VASP. Fe3O4 bulk structure has been computed including the Hubbard (U) parameter. One oxygen site (Ooct1) is studied as a probable site among the six Fe3O4 (111) terminations. Cr atom substitution on this surface is also examined. Cr atoms prefer being on the surface rather than in the ...
Citation Formats
M. Yarar, A. Bouzani, and D. Üner, “Pd as a reduction promoter for TiO2: Oxygen and hydrogen transport at 2D and 3D Pd interfaces with TiO2 monitored by TPR, operando 1H NMR and CO oxidation studies,” Catalysis Communications, vol. 174, pp. 0–0, 2023, Accessed: 00, 2023. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85143864348&origin=inward.