Gupta and Spivey84 have electrochemically synthesized nanowire/tube catalysts of Cu/ZnO (Figure 10, showing nanowires only)and Mn/Cu/ZnO using a template synthesis method. Thetechnique is depicted in Figure 9. A membrane is coated andplaced in an electrolyte solution containing ions of interest, andthen an appropriate current is applied to deposit these ions in thepores of the membrane. The membrane is dissolved usingmethylene chloride. Mn/Cu/ZnO catalysts with a wire morphology seem to be promising, with a 15.7% C selectivity for higheralcohols at low reaction pressure (10 bar). Cu/ZnO catalystswith a tubular morphology showed very low selectivity towardalcohols due to very low Cu content (2 wt %). Therefore,optimization of electrochemical conditions is required to increasethe amount of copper and compositional uniformity and to takeadvantage of the higher surface area of the tube morphology。Addition of manganese to Cu/ZnO nanowires improved theselectivity toward C2C4 alcohols from 5.4% to 15.7% C whilereducing methane and methanol formation.Microemulsions can provide localized reaction environmentsfor the synthesis of fine particles. In an effort to prepare catalystswith small metal particles interacting strongly with the support,Su et al.85 used a method involving water-in-oil microemulsions.Droplets of Fe(NO3)3 or Cu(NO3)2 aqueous solution werestabilized in a continuous toluene phase by the surfactantdodecylbenzenesulfonic acid sodium. After addition of NaOH,the pH was adjusted to 2.02.8 with HNO3 to separate theorganic sol. Following collection of this layer, the solvent wasremoved and “ultrafine” particles of Fe(OH)3 or Cu(OH)2 wereobtained. The mean size of Fe(OH)3 particles was 17.1 nm,whereas that of Cu(OH)2 particles was 6.65 μm. Impregnation ofactivated Al2O3 into the organic sol of Fe(OH)3 and Cu(OH)2,followed by calcination, yielded the ultrafine catalysts. WhenCH3COOK was also dissolved into the organic sol prior toimpregnation (at a K loading of 1.6 wt %), the total alcohol yieldand C2þ content of the alcohols reached 0.25 g mL1 h1 and58.8 wt %, respectively. Without K loading, and at the same Al2O3loading (88.61 wt %), these values were 0.154 g mL1 h1 and59.8 wt %, respectively.