Spent commercial (Italian K-W, Dutch K-H) and lab-made active C-Zn acetate catalysts, 1 g each, were refluxed (8x) 1 h with 100 cm(3) H2O, 0.1 M HCl, or 0.1 M AcOH to leach out the Zn(AcO)(2) active phase from the catalyst surface. Commercial Norit (W-R-4ex) and active C prepared from peat and sawdust (with H3PO4 and ZnCl2 as binders), sp. surface 1058-1508 m(2) were used as catalyst carriers. W-R-4ex, 2 g, was impregnated with 15 mL aqueous (methanolic) 1 M (0.4 M) Zn(AcO)(2) at 353 K (333 10 for 6h (4 h) and filtered and the resulting 0.5-1.4% Zn catalyst was dried 2 h at 378 K (24 h at 303 K and 2 h at 353 K). The leaching efficiency (Table 3) was related to the active C specific surface, impregnation mode, and solvent type. The organic by-products left in the spent catalyst should be washed out with organic solvents before the active phase is leached out. HCl and AcOH solutions were best as leachants; H2O was effective only when Zn(AcO)(2) occurred at the catalyst surface as large compact crystals. The more macroporous the active C, the higher the Zn(AcO)(2) leach-out degree.