共 34 条
On-line deactivation of Au/TiO2 for CO oxidation in H2-rich gas streams
被引:25
作者:
Steyn, Johann
Pattrick, Gary
Scurrell, Michael S.
Hildebrandt, Diane
Raphulu, Mpfunzeni C.
van der Lingen, Elma
机构:
[1] MINTEK, Adv Mat Div, ZA-2125 Randburg, South Africa
[2] AngloGold Ashanti Ltd, ZA-2001 Johannesburg, South Africa
[3] Univ Witwatersrand, Sch Chem, Inst Mol Sci, Johannesburg, South Africa
[4] Univ Witwatersrand, Sch Chem & Met Engn, Johannesburg, South Africa
关键词:
Au/TiO2;
deactivation;
CO oxidation;
hydrogen;
PROX;
D O I:
10.1016/j.cattod.2007.03.002
中图分类号:
O69 [应用化学];
学科分类号:
081704 ;
摘要:
Au-based catalysts, known for ambient temperature CO oxidation, have to provide stable performance of up to 5000 h in order to be commercially applicable in automotive fuel cells. In this report, the on-line deactivation characteristics of Au/TiO2 in unconventional PROX conditions are discussed. As opposed to CO removal from air, results in this report suggests that carbonates have a minor effect on deactivation of Au/TiO2 in dry HZ-rich conditions. Also, no conclusive correlation between surface hydration and deactivation was observed. Rather, deactivation appeared to have occurred as a result of an intrinsic transformation in the oxidation state of the active species in the reducing operating conditions; a process which was reversible in an oxidizing atmosphere. (C) 2007 Elsevier B.V. All rights reserved.
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页码:254 / 259
页数:6
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