Some aspects on the losses of metal from the support in the hydrocarbonylation of methanol

The stability of the Rh/C catalysts during hydrocarbonylation of methanol w as studied by subjecting the catalysts to the individual reactants as well as their combinations in vapour phase (250 degrees C and 1 bar) and in liqu id phase (220 degrees C, 120 bar). Neither methanol and methyl iodide, nor hydrogen or carbon monoxide alone effectuated metal leaching, but hydrogen did induce agglomeration of metallic species. In the vapour phase reaction, 20-30% of the metal was lost at 1 bar, and 50% at 15 bar, and in liquid ph ase the losses were 20-70% at 120 bar, i.e., the losses increased with incr easing reaction pressure. Nevertheless, the activated carbon support affect ed product selectivity in the vapour phase conditions at 1 bar. (C) 1999 El sevier Science B.V. All rights reserved.