The deactivation behavior of the TiO2 used as a photo-catalyst for benzene oxidation

In this study, the deactivation behavior of TiO2 as a photocatalyst for benzene decomposition to carbon dioxide and water was investigated. The effect of space time on the benzene and carbon dioxide conversions were monitored. Benzene conversion and carbon dioxide production rates were not correlated, indicating accumulation of a carbon containing intermediate on the surface. This intermediate was blocking the active sites at a stiochiometry of 1 C:1 site. High space times favored the production of carbon dioxide therefore reduced the rate of accumulation of the surface poisoning intermediate.


Effect of swaging on microstructure and tensile properties of W-Ni-Fe alloys
DURLU, NURİ; Caliskan, N. Kaan; Bor, Sakir (Elsevier BV, 2014-01-01)
The objective of this study was to investigate the effect of swaging on the microstructure and tensile properties of high density two phase alloys 90W-7Ni-3Fe and 93W-4.9Ni-2.1Fe. Samples were liquid phase sintered under hydrogen and argon at 1480 degrees C for 30 min and then 15% cold rotary swaged. Measurement of microstructural parameters in the sintered and swaged samples showed that swaging slightly increased tungsten grain size in the longitudinal direction and slightly decreased tungsten grain size i...
On the mechanism of photocatalytic CO2 reduction with water in the gas phase
Üner, Deniz (2012-02-12)
The mechanism of photocatalytic reduction of CO2 with H2O over Pt-TiO2 films produced by the sol-gel deposition over glass beads was investigated. The accumulation of significant amount of carbonaceous intermediate on the surface followed by deactivation indicated the rate limiting reaction is the water splitting reaction, similar to the natural photosynthetic systems. When gas phase hydrogen was allowed in the system, the carbonaceous intermediates were converted to methane at rates higher than the artific...
Analysis of effects of temperature variation on deep drawing process using different constitutive laws
Demirkol, Rasih Hakan; Darendeliler, Haluk; Department of Mechanical Engineering (2019)
In this study, the influences of temperature variation in deep drawing process are investigated by changing the temperatures of the whole blank, a part of the blank, the punch and die. Different yield criteria and hardening rules are considered to form the constitutive relations. The numerical results are obtained by using a commercial finite element software. Whereas Von-Mises and Hill48 yield criteria are available in the finite element code, a subroutine is developed for embedding the Yld2003 yield crite...
The influence of relative humidity on photocatalytic oxidation of nitric oxide (NO) over TiO2
Üner, Deniz; Tabari, Taymaz (2015-11-01)
The influence of relative humidity on NO oxidation over commercial TiO2 (47 m(2)/g catalyst) was investigated. The experimental methodology followed the protocols described in ISO-22197: 2007 (E) standard. The adsorption characteristics of oxygen and H2O were monitored by adsorption calorimetry. Oxygen adsorption was low; on the contrary water vapor exhibited the characteristics of multilayer adsorption. In the first monolayer, the heats of adsorption of water sharply decreased from 180 to 80 kj/mol till ab...
Ernam, Selin; Üner, Deniz; Department of Chemical Engineering (2022-1-12)
The objective of this thesis is to investigate the bottlenecks of photocatalytic NO oxidation reaction. This reaction is used as a standard diagnostic tool for photocatalytic activity according to the well defined protocols described by the ISO Standard (22197-1-2007). One of the problems with photocatalytic NO oxidation is the transient period of NO conversion between the beginning of illumination and the time the conversions reach a steady state. The nature of this behavior depends strongly on parameters ...
Citation Formats
D. Üner, “The deactivation behavior of the TiO2 used as a photo-catalyst for benzene oxidation,” CATALYST DEACTIVATION 1999, pp. 411–414, 1999, Accessed: 00, 2020. [Online]. Available: