Non-isothermal reduction kinetics and mechanisms by hydrogen of CuAl spinel solid solution
The non-isothermal reduction kinetics by hydrogen of CuAl spinel solid solution was investigated using H2 temperature-programmed reduction at different heating rates methodology. The reduction process consists of four stages in terms of the reduction degree (α), corresponding to the reduction of non...
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Published in | Catalysis communications Vol. 173; p. 106570 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
01.01.2023
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The non-isothermal reduction kinetics by hydrogen of CuAl spinel solid solution was investigated using H2 temperature-programmed reduction at different heating rates methodology. The reduction process consists of four stages in terms of the reduction degree (α), corresponding to the reduction of non-spinel Cu2+, easily reducible spinel Cu2+, hardly reducible spinel Cu2+ (I), and hardly reducible spinel Cu2+ (II). The activation energy was between 83.2 and 122.1 kJ mol−1 when α < 0.72, but increased sharply to ∼500 kJ mol−1 at α = 0.95, leading to different reduction mechanisms for these Cu2+ species. Furthermore, the phase transformation, spinel structure evolution, as well as reduction mechanism were investigated.
•Non-isothermal reduction kinetics of Cu-Al spinel solid solution are investigated.•The reduction process contains four stages in terms of the reduction degree.•High activation energy evidences low reducibility of hardly-reducible spinel Cu2+.•Different kinetic models are suitable to the reduction of different copper species.•Dynamic changes of both active Cu metal and Cu-Al spinel structure. |
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ISSN: | 1566-7367 1873-3905 |
DOI: | 10.1016/j.catcom.2022.106570 |