Composite catalyst bed and method for making the same

A process for making a composite catalyst bed, comprising:

• placing a three dimensional, structurally rigid foam metal matrix in a containing means,
• placing a plurality of separate pellet-like catalyst particles, each comprising a support carrier material that carries a catalyst material, within said matrix so as to substantially fill the matrix, and
• applying a compressive force to said matrix and catalyst particles to cause the surfaces of the catalyst particles and the matrix to conform to each other more closely so that the catalyst particles are better retained in the matrix.

A method of decomposing hydrazine based monopropellants which comprises flowing the monopropellant through a composite catalyst bed in pulse mode, wherein a large number of pressure pulses are exerted against said catalyst bed, wherein the catalyst bed comprises:

• a. a three dimensional, structurally rigid foam metal matrix, comprising a network of interconnected ligaments which define a plurality of interconnected pores and
• b. a plurality of separate pellet-like catalyst carrying particles, each comprising a supporting carrier material that carries a catalyst material, and positioned in and filling the pores of such matrix, with relative movement of said particles being restrained by said matrix,
• whereby with said matrix retaining said catalyst particles in proper position in said catalyst bed degradation of the catalyst particles is alleviated.

A method of oxidizing exhaust combustion products from an internal combustion engine comprising blowing the exhaust combustion products through a catalyst bed comprising:

• a. a three dimensional, structurally rigid foam metal matrix, comprising a network of interconnected ligaments which define a plurality of interconnected pores, and
• b. a plurality of separate pellet-like catalyst carrying particles, each comprising a supporting carrier material that carries a catalyst material, and positioned in and filling the pores of such matrix, with relative movement of said particles being restrained by said matrix,
• whereby with pressure pulses of said engine causing corresponding pressure pulses exerted on said catalyst bed, said catalyst particles are properly retained in the catalyst bed by the foam metal matrix.

A composite catalyst bed comprising:

• a. a three dimensional matrix comprising a network of interconnected ligaments, having internal passageways forming a network of interconnected passageways, said passageways having a wick material therein and a vaporizable liquid, with said vaporizable liquid and wick material functioning as a heat pipe to conduct heat from one portion of said matrix to another, and
• b. a plurality of separate pellet-like catalyst carrying particles, each comprising a supporting carrier material that carries a catalytic material, and positioned within said matrix, with said matrix conducting heat from higher temperature areas of said composite catalyst bed to lower temperature areas thereof.