Metal–Support Interactions between Nanosized Pt and Metal Oxides (WO3 and TiO2) Studied Using X-ray Photoelectron Spectroscopy

2011 ◽  
Vol 115 (41) ◽  
pp. 20153-20159 ◽  
Author(s):  
Adam Lewera ◽  
Laure Timperman ◽  
Agata Roguska ◽  
Nicolas Alonso-Vante
Keyword(s):  
Metal Oxides ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Metal Support ◽  
Metal Support Interactions

scholarly journals Synthesis and Characterization of Pd over Novel TiO2 Mixtures: Insights on Metal–Support Interactions

2020 ◽  
Vol 2 (1) ◽  
pp. 13
Author(s):  
Matías G. Rinaudo ◽  
Ana M. Beltrán ◽  
María A. Fernández ◽  
Luis E. Cadús ◽  
Maria R. Morales
Keyword(s):  
Photoelectron Spectroscopy ◽  
Anatase Phase ◽  
High Energy ◽  
Atomic Ratio ◽  
Oxidation Reactions ◽  
X Ray ◽  
Surface Areas ◽  
Scanning Transmission ◽  
Metal Support ◽  
Metal Support Interactions

Palladium nanoparticles were supported on unusual mixtures of anatase, TiO2 (II) and rutile titania phases by wet impregnation, obtaining catalysts with metal contents of ca. 0.25 wt % labeled Pd/Ti5, Pd/Ti45, and Pd/Ti120. Crystalline structures were confirmed by X-ray diffraction. Pd particle sizes in the range of 4–20 nm were observed by scanning-transmission electron Microscopy. External surface areas (SBET) in the range 10–17 m2 g−1 were higher enough to achieve a good distribution of palladium over titanium oxide outer surface, as evidenced by energy-dispersive X-ray spectroscopy elemental profiles. Pd0/Pdδ+ atomic ratio measured by X-ray photoelectron spectroscopy showed a decrease from Pd/Ti5 to Pd/Ti120, in line with the decrease in anatase phase present in the catalysts. This behavior suggested that palladium tended to form more TiPdxO structures in Pd/Ti5 whilst PdOx structures were more likely to be present on supports with greater amounts of TiO2 (II) and rutile, due to the distinct metal–support interactions. An increase in reducibility and oxygen mobility from Pd/Ti5 to Pd/Ti120 was observed by temperature programmed measurements and associated to the different high-energy ball milled supports. Catalysts with improved properties reported herein could exhibit an excellent performance in oxidation reactions, e.g., glycerol selective oxidation.

Carbon Supported Pt+Os Catalysts for Methanol Oxidation

2002 ◽  
Vol 57 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Gülsün Gökağaç ◽  
Brendan J. Kennedy
Keyword(s):  
Methanol Oxidation ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Carbon Support ◽  
Methanol Oxidation Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Metal Metal ◽  
Metal Support

11% Pt/C, 10% Pt + 1%Os/C, 9% Pt + 2%Os/C, 8% Pt + 3%Os/C, 7% Pt + 4%Os/C, 6% Pt + 5%Os/C and 5%Pt + 6% Os/C catalysts have been prepared for methanol oxidation reaction. Transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and cyclic voltammetry have been used to understand the nature of the species present in these catalysts. 7% Pt + 4% Os/C was the most active catalyst, while 8% Pt + 3% Os/C was the least active one. It is found that the metal particle size and distribution on the carbon support, the surface composition and the oxidation states of the metal particles, the metal-metal and metal support interactions are important parameters to define the activity of the catalyst.

Catalytic Properties of Surfaces Sites on Metal Oxides and Their Characterization by X-Ray Photoelectron Spectroscopy

1974 ◽  
Author(s):  
R. G. Squires ◽  
L. F. Albright ◽  
W. N. Delgass ◽  
R. A. Walton ◽  
N. Winograd
Keyword(s):  
Metal Oxides ◽  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
X Ray

scholarly journals Breaking Simple Scaling Relations Through Metal-Oxide Interactions: Understanding Room Temperature Activation of Methane on M-CeO2 (M= Pt, Ni or Co) Interfaces

2020 ◽  
Author(s):  
Pablo Lustemberg ◽  
Feng Zhang ◽  
Ramón A. Gutiérrez ◽  
Pedro J. Ramírez ◽  
Sanjaya D. Senanayake ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Ambient Pressure ◽  
Scaling Relations ◽  
Time Resolved ◽  
X Ray ◽  
Metal Support ◽  
Simple Scaling

The clean activation of methane at low temperatures remains an eminent challenge and a field of competitive research. In particular, on late transition metal surfaces such as Pt(111) or Ni(111), elevated temperatures are necessary to activate the hydrocarbon molecule, but a massive deposition of carbon makes the metal surface useless for catalytic activity. However, on very low-loaded M/CeO2 (M= Pt, Ni, or Co) surfaces, the dissociation of methane occurs at room temperature, which is unexpected considering simple linear scaling relationships. This intriguing phenomenon has been studied using a combination of experimental techniques (ambient-pressure X-ray photoelectron spectroscopy, time-resolved X-ray diffraction and X-ray absorption spectroscopy) and density functional theory-based calculations. The experimental and theoretical studies show that the size and morphology of the supported nanoparticles together with strong metal-support interactions are behind the deviations from the scaling relations. These findings point toward a possible strategy to circumvent scaling relations, producing active and stable catalysts which can be employed for methane activation and conversion. <br>

Strong metal–support interactions in Pd/Co3O4 catalyst in wet methane combustion: in situ X-ray absorption study

2020 ◽  
Vol 10 (13) ◽  
pp. 4229-4236
Author(s):  
William Barrett ◽  
Somaye Nasr ◽  
Jing Shen ◽  
Yongfeng Hu ◽  
Robert E. Hayes ◽  
...  
Keyword(s):  
Methane Combustion ◽  
Absorption Study ◽  
X Ray ◽  
Metal Support ◽  
Metal Support Interactions ◽  
X Ray Absorption

CoOx inhibits Pd oxidation in CH4 combustion in the wet feed.

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