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Kinetics of Valeric Acid Ketonization and Ketenization in Catalytic Pyrolysis on Nanosized SiO 2 , γ‐Al 2 O 3 , CeO 2 /SiO 2 , Al 2 O 3 /SiO 2 and TiO 2 /SiO 2
Author(s) -
Kulyk Kostiantyn,
Palianytsia Borys,
Alexander John D.,
Azizova Liana,
Borysenko Mykola,
Kartel Mykola,
Larsson Mats,
Kulik Tetiana
Publication year - 2017
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201601370
Subject(s) - valeric acid , catalysis , chemistry , fourier transform infrared spectroscopy , pyrolytic carbon , pyrolysis , oxide , activation energy , desorption , chemical engineering , inorganic chemistry , organic chemistry , acetic acid , adsorption , engineering
Valeric acid is an important renewable platform chemical that can be produced efficiently from lignocellulosic biomass. Upgrading of valeric acid by catalytic pyrolysis has the potential to produce value added biofuels and chemicals on an industrial scale. Understanding the different mechanisms involved in the thermal transformations of valeric acid on the surface of nanometer‐sized oxides is important for the development of efficient heterogeneously catalyzed pyrolytic conversion techniques. In this work, the thermal decomposition of valeric acid on the surface of nanoscale SiO 2 , γ‐Al 2 O 3 , CeO 2 /SiO 2 , Al 2 O 3 /SiO 2 and TiO 2 /SiO 2 has been investigated by temperature‐programmed desorption mass spectrometry (TPD MS). Fourier transform infrared spectroscopy (FTIR) has also been used to investigate the structure of valeric acid complexes on the oxide surfaces. Two main products of pyrolytic conversion were observed to be formed depending on the nano‐catalyst used—dibutylketone and propylketene. Mechanisms of ketene and ketone formation from chemisorbed fragments of valeric acid are proposed and the kinetic parameters of the corresponding reactions were calculated. It was found that the activation energy of ketenization decreases in the order SiO 2 >γ‐Al 2 O 3 >TiO 2 /SiO 2 >Al 2 O 3 /SiO 2 , and the activation energy of ketonization decreases in the order γ‐Al 2 O 3 >CeO 2 /SiO 2 . Nano‐oxide CeO 2 /SiO 2 was found to selectively catalyze the ketonization reaction.