Method of making layered catalysts
AssigneeGeneral Motors Corporation
InventorMichael J. D'Aniello, Jr.
Life of this patent
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Abstract
In a preferred embodiment a solution of a suitable noble metal compound in acetone or other C.sub.1 to C.sub.3 dialkyl ketone is used to selectively place a noble metal catalyst in a very thin layer on an alumina or base metal modified alumina carrier particle.
Claims4
A method of selectively placing noble metal catalyst material on a thin layer of a porous, high surface area alumina or base metal-containing alumina carrier particle where the layer may either be at the apparent outer surface of the particle or, if desired, submerged below the outer surface, comprising
- saturating the pores of said particle with liquid C.sub.1 to C.sub.3 dialkyl ketone,
- if necessary, blocking absorbent pore surface sites in said particle outwardly of the desired position of said layer by applying thereto an acid blocking agent,
- contacting said particle with a solution of a noble metal catalyst material in a substantially water-free C.sub.1 to C.sub.3 dialkyl ketone whereby the catalyst material is strongly absorbed on said particle on a layer beginning with the outermost unblocked sites and extending inwardly into said particle a depth determined by the amount of noble metal material in said solution, and
- calcining said particle to remove said blocking agent, if present, and to fix said noble metal catalyst.
A method of selectively placing noble metal catalyst material on a thin layer of a porous, high surface area alumina or base metal-containing alumina carrier particle where the layer may either be at the apparent outer surface of the particle or, if desired, submerged below the outer surface, comprising
- saturating the pores of said particle with acetone,
- if necessary, blocking absorbent pore surface sites in said particle outwardly of the desired position of said layer by applying thereto an acid blocking agent,
- contacting said particle with a solution of a noble metal catalyst material in substantially water-free acetone whereby the catalyst material is strongly absorbed on said particle on a layer beginning with the outermost unblocked sites and extending inwardly into said particle a depth determined by the amount of noble metal material in said solution, and
- calcining said particle to remove said blocking agent, if present, and to fix said noble metal catalyst.
A method of placing noble metal catalyst material on a microporous, high surface area alumina or base metal-containing alumina particle dispersed in a sharp, dense band beginning at the apparent outer surface of the particle and extending inwardly therefrom a desired band width, comprising
- saturating the pores of said particle with acetone,
- contacting said particle with a solution of a noble metal catalyst material in acetone whereby the catalyst material is strongly absorbed on said particle on absorbent pore surface sites beginning at the apparent outer surface of of the particle and extending inwardly into said particle a band width determined by the amount of said material in said solution, and
- calcining said particle to fix said noble metal catalyst.
A method of placing noble metal catalyst material on a microporous, high surface area alumina or base metal-containing alumina particle such that the catalyst is dispersed thereon in two or more sharp, dense bands, the first band beginning at the outer apparent surface of the particle and extending inwardly a first band width and the second band beginning inward of said first band and extending further inward a second band width, comprising
- saturating the pores of said particle with acetone,
- blocking absorbent pore surface sites in said particle outwardly of the desired position of the second band with an acid blocking agent,
- contacting said particle with a solution of noble metal catalyst material in acetone whereby the catalyst material is strongly absorbed on said particle as said second band,
- calcining said particle to remove said blocking agent and to fix the second catalyst band,
- contacting said particle with a solution of noble metal catalyst material in acetone whereby the catalyst material is strongly absorbed on said particle as said first band, and
- calcining said particle to fix the first catalyst band.
Dependencies are inferred from the claim text.