AN INFRARED STUDY OF THE INTERACTIONS OF CO AND CO2 WITH CU/SIO2

被引:46
作者
CLARKE, DB [1 ]
SUZUKI, I [1 ]
BELL, AT [1 ]
机构
[1] UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720
关键词
D O I
10.1006/jcat.1993.1186
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
The adsorption of CO and CO2 on Cu/SiO2 have been investigated by infrared spectroscopy. CO adsorbs on Cu with a heat of adsorption of 8.4 kcal/mol, whereas CO2 weakly adsorbs on both Cu and SiO2 with a heat of adsorption of 6.9 kcal/mol. As much as 24% of the adsorbed CO2 is associated with Cu, and the rest with the silica support. On freshly reduced Cu/SiO2, adsorbed CO exhibits an infrared band 2103 cm-1 whereas CO2 exhibits a band at 2340 cm-1 when adsorbed on both SiO2 and Cu surfaces. A band at 2118 cm-1 is also observed during CO2 exposure. This feature is attributable CO associated with Cu+ formed via the dissociation of CO2 into COS and OS. The extent of CO2 dissociation on Cu is measured to be about 20%. During CO2 exposure the coverage of adsorbed CO increases rapidly, goes through a maximum, and then decays. This transient is attributable to the competition of CO and CO2 for Cu sites. The effects on the CO2 dissociation transient of temperature, pressure, space velocity, catalyst preoxidation, and H2 addition can be explained with the proposed mechanism. © 1993 Academic Press, Inc.
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页码:27 / 36
页数:10
相关论文
共 45 条
[1]   CHEMISORPTION OF CO ON CU(100) STUDIED WITH ANGLE RESOLVED PHOTOELECTRON-SPECTROSCOPY [J].
ALLYN, CL ;
GUSTAFSSON, T ;
PLUMMER, EW .
SOLID STATE COMMUNICATIONS, 1977, 24 (08) :531-534
[2]   VIBRATIONAL EXCITATIONS AND STRUCTURE OF CO CHEMISORBED ON CU(100) [J].
ANDERSSON, S .
SURFACE SCIENCE, 1979, 89 (1-3) :477-485
[3]   THE NATURE OF THE METAL CO INTERACTION AND BONDING [J].
BAGUS, PS ;
NELIN, CJ ;
BAUSCHLICHER, CW .
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS, 1984, 2 (02) :905-909
[4]  
CHESTERS MA, 1972, ADSORPTION DESORPTIO
[5]   PROMOTION OF METHANOL SYNTHESIS AND THE WATER-GAS SHIFT REACTIONS BY ADSORBED OXYGEN ON SUPPORTED COPPER-CATALYSTS [J].
CHINCHEN, GC ;
SPENCER, MS ;
WAUGH, KC ;
WHAN, DA .
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS I, 1987, 83 :2193-2212
[6]   THE REACTIVE CHEMISORPTION OF CARBON DIOXIDE AT MAGNESIUM AND COPPER SURFACES AT LOW TEMPERATURE [J].
Copperthwaite, R. G. ;
Davies, P. R. ;
Morris, M. A. ;
Roberts, M. W. ;
Ryder, R. A. .
CATALYSIS LETTERS, 1988, 1 (1-3) :11-19
[7]   INTERACTION OF CO WITH CU+ CATIONS - CO ADSORPTION ON CU2O(100) [J].
COX, DF ;
SCHULZ, KH .
SURFACE SCIENCE, 1991, 249 (1-3) :138-148
[8]   AN INFRARED SPECTROSCOPIC STUDY OF THE ADSORPTION OF CARBON-MONOXIDE ON SILICA-SUPPORTED COPPER PARTICLES [J].
DEJONG, KP ;
GEUS, JW ;
JOZIASSE, J .
APPLIED SURFACE SCIENCE, 1980, 6 (3-4) :273-287
[9]   ON THE DETERMINATION OF COPPER SURFACE-AREA BY REACTION WITH NITROUS-OXIDE [J].
EVANS, JW ;
WAINWRIGHT, MS ;
BRIDGEWATER, AJ ;
YOUNG, DJ .
APPLIED CATALYSIS, 1983, 7 (01) :75-83
[10]   INFRARED-SPECTRA OF ADSORBED SPECIES PRESENT DURING OXIDATION OF ETHYLENE OVER SILVER [J].
FORCE, EL ;
BELL, AT .
JOURNAL OF CATALYSIS, 1975, 38 (1-3) :440-460