We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Catalytic Pyrolysis of Aliphatic Carboxylic Acids into Symmetric Ketones over Ceria-Based Catalysts: Kinetics, Isotope Effect and Mechanism.
- Authors
Kulik, Tetiana; Palianytsia, Borys; Larsson, Mats
- Abstract
Ketonization is a promising way for upgrading bio-derived carboxylic acids from pyrolysis bio-oils, waste oils, and fats to produce high value-added chemicals and biofuels. Therefore, an understanding of its mechanism can help to carry out the catalytic pyrolysis of biomass more efficiently. Here we show that temperature-programmed desorption mass spectrometry (TPD-MS) together with linear free energy relationships (LFERs) can be used to identify catalytic pyrolysis mechanisms. We report the kinetics of the catalytic pyrolysis of deuterated acetic acid and a reaction series of linear and branched fatty acids into symmetric ketones on the surfaces of ceria-based oxides. A structure–reactivity correlation between Taft's steric substituent constants Es* and activation energies of ketonization indicates that this reaction is the sterically controlled reaction. Surface D3-n-acetates transform into deuterated acetone isotopomers with different yield, rate, E≠, and deuterium kinetic isotope effect (DKIE). The obtained values of inverse DKIE together with the structure–reactivity correlation support a concerted mechanism over ceria-based catalysts. These results demonstrate that analysis of Taft's correlations and using simple equation for estimation of DKIE from TPD-MS data are promising approaches for the study of catalytic pyrolysis mechanisms on a semi-quantitative level.
- Subjects
PYROLYSIS; ACETONE; CARBOXYLIC acids; LINEAR free energy relationship; KETONIC acids; KINETIC isotope effects; PYROLYSIS kinetics
- Publication
Catalysts (2073-4344), 2020, Vol 10, Issue 2, p179
- ISSN
2073-4344
- Publication type
Article
- DOI
10.3390/catal10020179