Regeneration of Pd/TiO2 catalyst deactivated in reductive CCl4 transformations by the treatment with supercritical CO2, ozone in supercritical CO2 or oxygen plasma

Overview

Title: 

Regeneration of Pd/TiO2 catalyst deactivated in reductive CCl4 transformations by the treatment with supercritical CO2, ozone in supercritical CO2 or oxygen plasma

Abstract: 

Carbonaceous deposits formation was established as the primary reason of Pd/TiO2 catalyst deactivation during reductive processing of CCl4 to form hydrodechlorination and oligomerization products. Three methods of carbonaceous deposits elimination were tested: (1) extraction by supercritical CO2, (2) oxidation by ozone in supercritical CO2, and (3) low-temperature glow-discharge oxygen plasma treatment. Synchronic thermal analysis confirms effective carbonaceous deposits removal during regeneration by ozone or low temperature glow-discharge oxygen plasma; by XPS deep oxidation of surface Pd after oxidative treatment (by ozone or oxygen plasma) was found. Thus H-2 reduction was proposed as the second step making possible full regeneration of initial catalytic activity of Pd/TiO2. (C) 2011 Elsevier B.V. All rights reserved.

Authors: 

Ekaterina S. Lokteva, Aleksey E. Lazhko, Elena V. Golubina, Vadim V. Timofeev, Alexander V. Naumkin, Tatiana V. Yagodovskaya, Sergey N. Gaidamaka, Valery V. Lunin

DOI: 

Journal: 

Journal Of Supercritical Fluids

Year: 

2011

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