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Sol–gel derived CeO 2 /α‐Al 2 O 3 bilayer thin film as an anti‐coking barrier and its catalytic coke oxidation performance
Author(s) -
Kwon Hyuk T.,
Bukhovko Maxim P.,
Mahamulkar Shilpa,
Sulmonetti Taylor,
Min Byunghyun,
Almas Qandeel,
Malek Andrzej,
Li Liwei,
Agrawal Pradeep K.,
Jones Christopher W.
Publication year - 2018
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.16383
Subject(s) - incoloy , bilayer , catalysis , chemical engineering , layer (electronics) , substrate (aquarium) , materials science , coke , alloy , chemistry , nanotechnology , metallurgy , organic chemistry , membrane , biochemistry , oceanography , geology , engineering
A CeO 2 /α‐Al 2 O 3 bilayer was coated on a high temperature alloy (Incoloy 800H) by sol–gel dip‐coating and was evaluated for its potential as an anticoking barrier and coke oxidation catalyst. The bilayer effectively functioned as a barrier to metal surface catalyzed coking. The film prevented filamentous catalytic coking via blocking surface active metallic sites on the Incoloy substrate. Furthermore, the bilayer reduced the oxidation temperature of pyrolytic coke deposited on the film surface as compared to a bare oxidized Incoloy substrate, mostly owing to the oxidation catalytic activity of the CeO 2 layer. Finally, it is demonstrated that the presence of the α‐Al 2 O 3 buffer layer is critically important to the overall performance. Without the α‐Al 2 O 3 layer, a CeO 2 layer nearly completely lost both its barrier and oxidation catalytic functions. It is presumed that metallic species migrating from the substrate during high temperature treatments are responsible for the CeO 2 deactivation, likely by blocking catalytic sites on the CeO 2 surface. © 2018 American Institute of Chemical Engineers AIChE J , 64: 4019–4026, 2018