Experimental Microkinetic Approach of the Photocatalytic Oxidation of Isopropyl Alcohol on TiO2. Part 1. Surface Elementary Steps Involving Gaseous and Adsorbed C3HxO Species
- Resource Type
- Authors
- Corinne Ferronato; Jean-Marc Chovelon; Daniel Bianchi; J.M. Herrmann; Arsac F
- Source
- The Journal of Physical Chemistry A. 110:4202-4212
- Subject
- Anatase
Photochemistry
Surface Properties
Ultraviolet Rays
Kinetics
Inorganic chemistry
Activation energy
Catalysis
2-Propanol
Acetone
chemistry.chemical_compound
Adsorption
Reaction rate constant
Organic chemistry
Physical and Theoretical Chemistry
Titanium
Water
Isopropyl alcohol
Carbon Dioxide
chemistry
Photocatalysis
Gases
Oxidation-Reduction
- Language
- ISSN
- 1520-5215
1089-5639
The present study concerns an experimental microkinetic approach of the photocatalytic oxidation (PCO) of isopropyl alcohol (IPA) into acetone on a pure anatase TiO2 solid according to a procedure previously developed. Mainly, the kinetic parameters of each surface elementary step of a plausible kinetic model of PCO of IPA are experimentally determined: natures and amounts of the adsorbed species and rate constants (preexponential factor and activation energy). The kinetics parameters are obtained by using experiments in the transient regime with either a FTIR or a mass spectrometer as a detector. The deep oxidation (CO2 and H2O formation) of low concentrations of organic pollutants in air is one of the interests of the PCO. For IPA, literature data strongly suggest that acetone is the single route to CO2 and H2O and this explains that the present study is dedicated to the elementary steps involving gaseous and adsorbed C3H(x)O species. The microkinetic study shows that strongly adsorbed IPA species (two species denoted nd-IPA(sads) and d-IPA(sads) due to non- and dissociative chemisorption of IPA, respectively) are involved in the PCO of IPA. A strong competitive chemisorption between IPA(sads) and a strongly adsorbed acetone species controls the high selectivity in acetone of the PCO at a high coverage of the surface by IPA(sads). The kinetic parameters of the elementary steps determined in the present study are used in part 2 to provide a modeling of macroscopic kinetic data such as the turnover frequency (TOF in s(-1)) of the PCO using IPA/O2 gas mixtures.