TPD Study of Carbon Monoxide Interaction with Pd/Nb Bimetallic System

1994 ◽  
Vol 59 (8) ◽  
pp. 1709-1720 ◽  
Author(s):  
Tomas Jirsak ◽  
Vladimír Nikolajenko ◽  
Zlatko Knor
Keyword(s):  
Thin Films ◽  
Work Function ◽  
Room Temperature ◽  
Temperature Programmed Desorption ◽  
Foil Surface ◽  
Temperature State ◽  
Bimetallic System ◽  
Adsorption Of Co ◽  
Higher Temperature ◽  
Temperature Programmed

Chemisorption properties of thin films of Pd evaporated onto Nb recrystallized-foil surface have been studied by temperature-programmed desorption (TPD) and by measurement of the work function changes (WFC) at room temperature. TPD results indicate two states of CO adsorbed in dependence on the thickness of the palladium layer. The low temperature state (330 K) occurs at low Pd coverages (about one monolayer). Second state, occurring at slightly higher temperature (370 K), is attributed to bulk Pd. WFC data show negligible change of the work function after deposition of small amounts of Pd onto a clean Nb surface. With increasing amount of Pd, ∆ϕ rises and reaches a saturation value. Adsorption of CO onto Pd/Nb surface caused the work function increase at all coverages of Pd deposited.

Elektronische Wechselwirkung zwischen Kohlenmonoxyd und aufgedampften Ge-Filmen mit reiner oder mit Sauerstoff vorbelegter Oberfläche

1963 ◽  
Vol 18 (5) ◽  
pp. 633-638
Author(s):  
R. Suhrmann ◽  
M. Kruel ◽  
G. Wedler
Keyword(s):  
Room Temperature ◽  
High Vacuum ◽  
Electron Donors ◽  
Band Model ◽  
Electronic Interaction ◽  
Electric Resistance ◽  
Before And After ◽  
Adsorption Of Co ◽  
Higher Temperature ◽  
Ordered State

Ge-films are evaporated under high vacuum conditions at 77°K. They are investigated either in the disordered state (before annealing at a higher temperature) or in the ordered state after annealing. The electric resistance R and the photoelectric work function Φ are measured before and after the influence of known amounts of carbon monoxide. R is plotted as a function of time and coverage n, Φ as a function of n. At 77°K an electronic interaction between the CO molecules and the Ge-film follows from an observed irreversible and reversible increase in R; Φ is not altered. The discussion by means of a band model shows that the CO molecules act as electron donors. At room temperature no interaction is found. Films precovered with oxygen show two simultaneous reactions during the adsorption of CO: a stronger adsorption on the spots precovered with oxygen and a weaker one on the bare Ge surface.

scholarly journals Experimental Investigations of the Interaction of SO2 with MgO

1999 ◽  
Vol 590 ◽  
Author(s):  
Andrea Freitag ◽  
J. A. Rodriguez ◽  
J. Z. Larese
Keyword(s):  
High Resolution ◽  
Film Thickness ◽  
Room Temperature ◽  
Temperature Programmed Desorption ◽  
Experimental Investigations ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Temperature Programmed ◽  
X Ray Absorption

ABSTRACTHigh resolution adsorption isotherms, temperature programmed desorption (TPD), x-ray diffraction (XRD) and x-ray absorption near edge spectroscopy (XANES) methods were used to investigate the interaction of SO2 with high quality MgO powders. The results of these investigations indicate that when SO2 is deposited on MgO in monolayer quantities at temperatures near 100K both SO3 and SO4 species form that are not removed by simply pumping on the pre-dosed samples at room temperature. TPD and XANES studies indicate that heating of pre-dosed MgO samples to temperatures above 350 °C is required for full removal of the SO3/SO4 species. XANES measurements made as a function of film thickness indicate for coverages near monolayer completion that the SO4 species form first.

Temperature Programmed Desorption of Carbon Dioxide for Activated Carbon Supported Nickel Oxide: The Adsorption and Desorption Studies

2015 ◽  
Vol 1087 ◽  
pp. 45-49 ◽  
Author(s):  
Azizul Hakim ◽  
Wan Nor Roslam Wan Isahak ◽  
Maratun Najiha Abu Tahari ◽  
Muhammad Rahimi Yusop ◽  
Mohamed Wahab Mohamed Hisham ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Room Temperature ◽  
Low Cost ◽  
Temperature Programmed Desorption ◽  
High Adsorption ◽  
Solid Sorbents ◽  
Potential Source ◽  
Temperature And Pressure ◽  
Temperature Programmed ◽  
Preliminary Support

The priority of success in practical CO2 capture with solid sorbents is dependent on the development of a low cost sorbent and energy consumption for regeneration with high adsorption capacity. In this work, different loading of NiO were evaluated as a potential source of basic sites for CO2 capture, and activated carbon (AC) was used as a preliminary support in order to study the effect of the impregnation. The NiO loading increased the basicity of the adsorbent significantly enhance the CO2 chemisorption. Nonetheless, it drastically reduced the surface area of the AC, which is chiefly responsible for CO2 physisorption, thus decreasing the carrying capacity of ACs at room temperature and pressure.

scholarly journals Temperature-programmed desorption of H2 from molybdenum nitride thin films

1994 ◽  
Vol 78 (3) ◽  
pp. 299-307 ◽  
Author(s):  
Jeong-Gil Choi ◽  
Hyuek Joon Lee ◽  
Levi T. Thompson
Keyword(s):  
Thin Films ◽  
Temperature Programmed Desorption ◽  
Molybdenum Nitride ◽  
Temperature Programmed

scholarly journals P1.8.10 Work Function Gas Sensors at Room Temperature by means of Conductive Polypyrrole Thin-films

2012 ◽  
Author(s):  
C. R. Zamarreño ◽  
I. R. Matias ◽  
F. J. Arregui ◽  
P. Davydovskaya ◽  
R. Pohle ◽  
...  
Keyword(s):  
Thin Films ◽  
Work Function ◽  
Gas Sensors ◽  
Room Temperature ◽  
Conductive Polypyrrole

CO adsorption on (100) and (211) tungsten single-crystal surfaces: Changes in work function

1968 ◽  
Vol 46 (8) ◽  
pp. 949-958 ◽  
Author(s):  
R. A. Armstrong
Keyword(s):  
Single Crystal ◽  
Work Function ◽  
Single Crystals ◽  
Room Temperature ◽  
Co Adsorption ◽  
Major Effect ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Tungsten Single Crystal ◽  
Adsorption Of Co

The adsorption of CO on two large single crystals of tungsten exposing (100) and (211) surfaces has been studied by measuring changes in the work function [Formula: see text] at 300 °K and above, where some CO remained adsorbed. The results for the two surfaces were quite different.CO adsorbed on the clean W(100) surface at room temperature as β-CO causing [Formula: see text] to increase by 0.48 V. As β adsorption saturated, α-CO adsorption began and caused [Formula: see text] to decrease. The major effect of heating was desorption.CO adsorbed on the clean W(211) surface with a sticking probability near unity and increased [Formula: see text] by 0.68 V. Heating the crystal to temperatures below 1100 °K produced large irreversible changes in [Formula: see text]. These irreversible changes are attributed to the formation and dissociation on the surface of complexes consisting of two CO molecules.

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