Alumoxane precursors to designer catalysts and catalyst supports: catalystic oxidation of dichloromethane

摘要

Carboxylato-alumoxanes are aluminum-oxygen macromolecules consisting of a boehmite-like core surrounded by a sheath of carboxylate groups. The alumoxanes may be processed like organic polymers yet when fired are readily transformed into ceramic oxides. The alumoxanes can be precisely doped at room temperature in aqueous solution with a range of metal cations to prepare novel catalyst and catalyst support materials.The ease of introduction of multiple cations into the alumina lattice via the alumoxane approach provides a method fro fine-tuning catalyst support properties and the fabrication of new catalyst materials themselves. Manganese-doped alumina (Mn-Al_2O_3), formed via the doping of an alumoxane with Mn at room temperature, is presented as an example where the alumoxane route provides enhanced catalytic performance over traditional approaches for the low temperature catalytic oxidationof chlorinated hyrocarbons (CHCs). The Mn-Al_2O_3 formed from the Mn-doped alumoxane is compared with MnO_2/Al_2O_3 prepared by the incipient wetness method, and commercial Pt/Al_2O_3 for the oxidation/destruction of dichloromethane (CH_2Cl_2).