OSCILLATIONS OF CO AND CO+H-2 OXIDATION IN AIR OVER SUPPORTED AND UNSUPPORTED PT CATALYSTS

被引:6
作者
DENG, YQ
NEVELL, TG
JONES, MG
机构
[1] UNIV PORTSMOUTH,DEPT CHEM,PORTSMOUTH PO1 2DT,HANTS,ENGLAND
[2] CITY TECHNOL LTD,PORTSMOUTH PO6 1SZ,HANTS,ENGLAND
关键词
OSCILLATION; CO + H-2 COOXIDATION; CHEMICAL SENSOR; PELLISTOR; PLATINUM; PLATINUM ALUMINA;
D O I
10.1007/BF00806880
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Oscillation behaviour of the oxidation of CO (0.2-2.2%) in air over Pt wire coils and over Pt/Al2O3 catalysts deposited onto the coils (pellistors) has been investigated. The waveforms differ considerably between the two catalytic systems. Over unsupported Pt at 240-260 degrees C, regular oscillations were accompanied by slowly declining activity and by deposition of carbon. Over supported Pt at 110-180 degrees C, relatively complex but sustained oscillation occurred by a different mechanism. This oscillation was greatly enhanced by H-2 (0.25-1.0%), and may involve fluctuations in the concentrations of CO and H-2 around the supported catalyst.
引用
收藏
页码:313 / 320
页数:8
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