Water gas shift reaction: homogeneous catalysis by ruthenium and other metal carbonyls

Journal Article · Sun Feb 01 04:00:00 EST 1981 · Acc. Chem. Res.; (United States)

DOI:https://doi.org/10.1021/ar00062a001· OSTI ID:6378542

Ford, P C

A number of chemical systems are active for homogeneous, solution phase catalysis of the water gas shift reaction (WGSR). Catalysis of the shift reaction appears to be a quite general property of carbonyl complexes in alkaline solutions. The key mechanistic steps for which some kinetics information is available are the activation of coordinated CO by reaction with hydroxide and the reductive elimination of dihydrogen from a resulting metal hydride. Which of these is rate limiting in a cycle is a function of the specific metal system and the specific reaction conditions. A basic solution is not a necessary condition for WGSR catalysis. Although WGSR catalysis is not as general a phenomenon in acidic media, several such systems have been characterized with activities which compare very favorably to those seen in basic solutions. While logical mechanisms have been proposed for several of the better characterized catalysts, it is clear that a more complete mechanistic understanding of the key steps in potential cycles is greatly needed. Recognition of such needs has led to fundamental studies into the acid/base natures of metal carbonyl hydride clusters, of CO activation on cluster and mononuclear metal carbonyls by bases, and of dihydrogen elimination from and declusterification and clusterification reactions of metal carbonyl hydrides. While none of these processes is in itself catalytic, the sum of several represents possible cycles. With regard to the future of homogeneous WGSR catalysts, it is obvious that under the conditions which these have been tested, the known systems are not commercially viable. Certainly, for a reaction such as the WGSR for which effective heterogeneous catalysts are known, it will take substantial advantages for a new system to be an attractive alternative to established technology.

• Research Organization: Univ. of California, Santa Barbara
• OSTI ID: 6378542
• Journal Information: Acc. Chem. Res.; (United States), Journal Name: Acc. Chem. Res.; (United States) Vol. 14:2; ISSN ACHRE
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
080104* -- Hydrogen-- Production-- Water Gas Processes
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
HYDROGEN COMPOUNDS
HYDROGEN PRODUCTION
OXIDES
OXYGEN COMPOUNDS
PH VALUE
RUTHENIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
WATER
WATER GAS PROCESSES