Fischer Tropsch process Roelen catalysts

One of the most interesting catalytic reactions to be discovered is the so-called oxo reaction. The oxo reaction consists of the catalytic addition of carbon monoxide and hydrogen to olefins to form, primarily, aldehydes possessing one carbon atom more than the original olefin. This hy-droformylation reaction was developed during World War II by Roelen and co-workers (22) in Germany. While they utilized solid Fischer-Tropsch cobalt-thoria catalyst, it became apparent to them that the hydroformylation reaction was probably a homogeneous catalytic process with either dicobalt octaearbonyl or cobalt hydrocarbonyl as the catalyst. 

The hydroformylation of alkenes was accidentally discovered by Roelen while he was studying the Fischer-Tropsch reaction (syn-gas conversion to liquid fuels) with a heterogeneous cobalt catalyst in the late thirties. In a mechanistic experiment Roelen studied whether alkenes were intermediates in the "Aufbau" process of syn-gas (from coal, Germany 1938) to fuel. He found that alkenes were converted to aldehydes or alcohols containing one more carbon atom. It took more than a decade before the reaction was taken further, but now it was the conversion of petrochemical hydrocarbons into oxygenates that was desired. It was discovered that the reaction was not catalysed by the supported cobalt but in fact by HCo(CO)4 which was formed in the liquid state. 

During a study of the origin of oxygenates in Fischer-Tropsch synthesis in the presence of a cobalt catalyst, Roelen observed the formation of propanal and 3-penta-none when ethylene was added to the feed.1 The process now termed hydroformylation or oxo reaction is the metal-catalyzed transformation of alkenes with carbon monoxide and hydrogen to form aldehydes ... 

The hydroformylation or oxo reaction has been chosen for particular study for several reasons (a) The reaction was discovered by Roelen 2) in the course of an investigation of the mechanism of the Fischer-Tropsch reaction, and a study of the hydroformylation reaction could furnish information on the course of this heterogeneously catalyzed synthetic fuel process (6) hydroformylation involves the activation of hydrogen by a molecularly dispersed catalyst (c) there are few side reactions (d) the catalyst for the reaction, Co2(CO)s, is easily prepared, is relatively nontoxic, and is consequently readily available for study and (e) the reaction is of great industrial importance. 

Backgroxmd. Otto Roelen of Ruhrchemie, Germany, was chiefly responsible for development of the Oxo process. Some early work by Smith and his coworkers at the U.S. Bureau of Mines in 1930 had indicated that an increased yield of oxygenated compounds, as compared with conventional fischer-Tropsch practice, was obtmned when ethylene was added to water gas in the presence of cobalt catalyst at 200-225 C and atmospheric pressure. Roelen modified the operating conditions significantly and found that, at temperatures below 200°C "and pressures of 100-200 atm, all liquid products from the reaction of ethylene and water gas were oxygenated. He showed that the reaction could be applied generally to the formation of aldehydes from olefins and filed patents on the process as early as 1938. ... 

The discovery of hydroformylation by Otto Roelen was made while investigating the influence of alkenes on the Fischer-Tropsch reaction using a heterogeneous cobalt oxide catalyst supported on silica. Later it was concluded that hydroformylation is actually a homogeneous process catalyzed by ECo(CO) formed in situ. Many metals catalyze hydroformylation, but the most active catalysts contain cobalt, rhodium, palladium, and platinum as the central metal. The discussion in this chapter centers on the most utilized catalysts ECo(CO), ECo(CO)3PR3, ERh(CO)3(PR3)j, and HRhfCOljfdiphosphine). 

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