Patent ID: 6448199
Filing Date: 2002-09-10
Classification: B01J

Abstract:
A hydrophobic composite Pd-membrane catalyst, useful for the non-hazardous direct oxidation of hydrogen by oxygen to hydrogen peroxide, without a gas phase mixing of hydrogen and oxygen or air, said catalyst represented by the formula:HPM (c)/SOMF (b)/MxPd1âˆ’x(a)/IPM wherein:IPM is an inorganic ceramic porous membrane, permeable to all gases and vapors; MxPd1âˆ’x is a metal alloy permeable only to hydrogen gas, deposited on one side of IPM; Pd is a palladium metal; M is a metal other than palladium or a mixture of two or more thereof, x is a mole fraction of the metal M in the metal alloy (MxPd1âˆ’x), (a) is the weight of the metal alloy per unit area of IPM; SOMF is a surface oxidized thin metal film comprising palladium which is permeable only to hydrogen deposited on the metal alloy (MxPd1âˆ’x); (b) is the thickness of SOMF; HPM is a hydrophobic polymer membrane permeable to hydrogen and oxygen gases and also vapors of water and hydrogen peroxide but not to liquid water and aqueous solution, and (c) is the weight of the BPM per unit area of SOMF.