Turnover rate and kinetic mechanism for the reaction of hydrodechlorination of 1,1-dichlorotetrafluoroethane (CF3-CFCl2) over a polycrystalline Pd foil

被引:55
作者
Ribeiro, FH
Gerken, CA
Somorjai, GA
Kellner, CS
Coulston, GW
Manzer, LE
Abrams, L
机构
[1] UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720
[2] UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720
[3] DUPONT CO INC,EXPT STN,CENT RES & DEV,CORPORATE CATALYSIS CTR,WILMINGTON,DE 19880
关键词
hydrodechlorination rates and mechanism; Pd model catalysts; 1,1-dichlorotetrafluoroethane; CFC114a;
D O I
10.1023/A:1019036200398
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 kinetics (turnover rate, activation energy, reaction order) of catalytic hydrodechlorination of 1,1-dichlorotetrafluoroethane or CFC 114a (CF3-CFCl2) were determined on a similar to 0.5 cm(2) palladium polycrystalline foil as a catalyst. The reaction rates were measured in the temperature range of 80-200 degrees C at a total pressure of 770 Torr. Using a reaction cell that was connected to an ultrahigh vacuum surface characterization chamber the composition of the metal surface was monitored before and after reaction. The products formed in a parallel reaction network and the turnover rates at 150 degrees C, 50 Torr CFC 114a, 100 Torr H-2, and 0.1 Torr HCl were 2.1 s(-1) for CF3-CFH2, 3.0 x 10(-1) s(-1) for CF3-CFClH, and 6.4 x 10(-2) s(-1) for CF3-CH3. For the two most abundant products, the reaction order is 1 in CF3-CFCl2, 0.5 in H-2 and -1 in the reaction product HCl. These results suggest that the rate determining step for the reaction is the associative chemisorption of CF3-CFCl2 on the palladium surface. The palladium surface was free of adsorbates after the reaction with the exception of sulfur impurity that may accumulate during reaction.
引用
收藏
页码:149 / 153
页数:5
相关论文
共 16 条
[1]  
AINBINDER Z, IN PRESS HDB HETEROG
[2]   REACTIONS OF METHYL CHLORIDE AND OF METHYLENE CHLORIDE AT METAL SURFACES .2. REACTIONS OVER EVAPORATED FILMS OF TITANIUM AND OTHER METALS [J].
ANDERSON, JR ;
MCCONKEY, BH .
JOURNAL OF CATALYSIS, 1968, 11 (01) :54-&
[3]   CATALYTIC FISSION OF CARBON-HALOGEN BOND .2. REACTIONS OF TERTIARY BUTYL CHLORIDE WITH HYDROGEN AND DEUTERIUM ON EVAPORATED PLATINUM AND PALLADIUM FILMS [J].
CAMPBELL, JS ;
KEMBALL, C .
TRANSACTIONS OF THE FARADAY SOCIETY, 1963, 59 (491) :2583-&
[4]   CATALYTIC FISSION OF CARBON-HALOGEN BOND .1. REACTIONS OF ETHYL CHLORIDE AND ETHYL BROMIDE WITH HYDROGEN ON EVAPORATED METAL FILMS [J].
CAMPBELL, JS ;
KEMBALL, C .
TRANSACTIONS OF THE FARADAY SOCIETY, 1961, 57 (05) :809-&
[5]  
CAMPBELL JS, 1964, KINET KATAL, V5, P4
[6]   CONVERSION UNDER HYDROGEN OF DICHLORODIFLUOROMETHANE OVER BIMETALLIC PALLADIUM CATALYSTS [J].
COQ, B ;
HUB, S ;
FIGUERAS, F ;
TOURNIGANT, D .
APPLIED CATALYSIS A-GENERAL, 1993, 101 (01) :41-50
[7]   CONVERSION OF CHLOROBENZENE OVER PALLADIUM AND RHODIUM CATALYSTS OF WIDELY VARYING DISPERSION [J].
COQ, B ;
FERRAT, G ;
FIGUERAS, F .
JOURNAL OF CATALYSIS, 1986, 101 (02) :434-445
[8]   HYDROGENOLYSIS OF METHYL-CHLORIDE ON METALS [J].
FUNG, SC ;
SINFELT, JH .
JOURNAL OF CATALYSIS, 1987, 103 (01) :220-223
[9]   HYDROGENOLYSIS OF DICHLOROTETRAFLUOROETHANE ISOMERIC MIXTURES FOR THE FORMATION OF 1.1.1.2 - TETRAFLUOROETHANE [J].
GERVASUTTI, C ;
MARANGONI, L ;
MARRA, W .
JOURNAL OF FLUORINE CHEMISTRY, 1981, 19 (01) :1-20
[10]   REACTION HEATS OF ORGANIC HALOGEN COMPOUNDS .6. THE CATALYTIC HYDROGENATION OF SOME ALKYL FLUORIDES [J].
LACHER, JR ;
KIANPOUR, A ;
PARK, JD .
JOURNAL OF PHYSICAL CHEMISTRY, 1956, 60 (10) :1454-1455