J. F. Knifton
Dec 1, 1985
Citations
1
Influential Citations
30
Citations
Journal
Journal of Catalysis
Abstract
Abstract Acetic acid has been generated directly from synthesis gas ( CO H 2 ) in up to 95 wt% selectivity and 97% carbon efficiency using a RuCoI Bu 4 PBr “melt” catalyst combination. The critical roles of each of the ruthenium, cobalt and iodide catalyst components in achieving maximum selectivity to HOAc have been identified. C 1 -oxygenate formation is only observed in the presence of ruthenium carbonyls; [Ru(CO) 3 I 3 ] − is here the dominant species. Controlled quantities of iodide ensure that initially formed MeOH is rapidly converted to the more reactive methyl iodide. Subsequent cobalt-catalyzed carbonylation to acetic acid may be preparatively attractive (>80% selectivity) relative to competing syntheses where the [Co(CO) 4 ] − concentration is maximized; that is, where the Co/Ru ratio is > 1, the syngas feedstock is rich in CO and the initial iodide/cobalt ratios are close to unity. Formation of cobalt-iodide species in significant concentrations appears to be an inhibiting step in this synthesis.