Open AccessInfluence of Calcination Conditions on Structural and Solid‐State Kinetic Properties of Iron Oxidic Species Supported on SBA‐15
Author(s) -
Genz Nina Sharmen,
Ressler Thorsten
Publication year - 2019
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201900236
Subject(s) - calcination , physisorption , chemical engineering , materials science , inorganic chemistry , chemistry , catalysis , organic chemistry , engineering
Iron oxidic species supported on silica SBA‐15 were synthesized with various iron loadings using two different Fe III precursors. The effect of varying powder layer thickness during calcination on structural and solid‐state kinetic properties of Fe x O y /SBA‐15 samples was investigated. Calcination was conducted in thin (0.3 cm) or thick (1.3 cm) powder layer. Structural characterization of resulting Fe x O y /SBA‐15 samples was performed by nitrogen physisorption, X‐ray diffraction, and DR‐UV/Vis spectroscopy. Thick powder layer during calcination induced an increased species size independent of the precursor. However, a significantly more pronounced influence of calcination mode on species size was observed for the Fe III nitrate precursor compared to the Fe III citrate precursor. Temperature‐programmed reduction (TPR) experiments revealed distinct differences in reducibility and reduction mechanism dependent on calcination mode. Thick layer calcination of the samples obtained from Fe III nitrate precursor resulted in more pronounced changes in TPR profiles compared to samples obtained from Fe III citrate precursor. TPR traces were analyzed by model‐dependent Coats‐Redfern method and model‐independent Kissinger method. Differences in solid‐state kinetic properties of Fe x O y /SBA‐15 samples dependent on powder layer thickness during calcination correlated with differences in iron oxidic species size.