Preparation of Ru-Sn/Y zeolite catalysts with various precursors and theirapplication to acetic acid (methyl acetate) formation from methanol alone

New preparation methods for Ru-Sn/Y zeolites, which catalyze acetic acid (m ethyl acetate) formation from methanol alone in the gas-solid phase, were i nvestigated. When SnX2 (X = Cl, Br, I) was impregnated on a [RU(NH3)6](3+)/ Y zeolite from the methanol solution at the ratio oi [Sn]/[Ru] = 1.0, the h igher activity was obtained with X possessing the higher electronegativity (Cl > Br > I). The larger methyl acetate formation was observed by using a Ru precursor with chloride ligands, [RuCl2(NH3)(4)](+), and SnCl2. Introduc ing SnCl2 as a vapor afforded 14 and 10 times smaller amounts of Sn species on the [RU(NH3)6](3+)/Y and [RuCl2(NH3)(4)](+)/Y, respectively. Neverthele ss, the activities were almost the same for the former (3.1%-->2.9%)and som ewhat increased for the latter (6.2%-->8.4%), suggesting formation of more active species.