1. A method for making a catalyst composition, comprising the steps of combining dawsonite or a dawsonite derivative with a catalytic active element.
2. The method of claim 1, wherein the dawsonite derivative comprises amorphous alumina or mesoporous alumina.
3. The method of claim 2, wherein the dawsonite derivative is formed by heat-treating the dawsonite under conditions sufficient to calcine the dawsonite and convert the dawsonite to amorphous alumina.
4. The method of claim 3, wherein the heat treatment is carried out at a temperature in a range of about 300 degrees Celsius to about 600 degrees Celsius.
5. The method of claim 3, wherein the amorphous alumina is treated in an aqueous medium at a temperature above the boiling point of the aqueous medium, so as to convert the amorphous alumina to a mesoporous form.
6. The method of claim 5, wherein the aqueous treatment comprises immersing the amorphous alumina in boiling water.
7. The method of claim 5, wherein the aqueous treatment comprises steam treatment of the amorphous alumina.
8. The method of claim 1, further comprising the following steps after combining dawsonite with the catalytic active element;
(a) heat-treating the activated dawsonite material under conditions sufficient to calcinate the activated dawsonite material and convert the activated dawsonite material to an activated amorphous alumina material; and
(b) treating the activated amorphous alumina material in an aqueous medium at a temperature above the boiling point of the aqueous medium, so as to convert the amorphous alumina material to a mesoporous form.
9. The method of claim 8, wherein the heat treatment is carried out at a temperature in a range of about 300 degrees Celsius to about 600 degrees Celsius.
10. The method of claim 8, wherein the aqueous treatment comprises immersing the activated amorphous alumina in boiling water.
11. The method of claim 8, wherein the aqueous treatment comprises steam treatment of the activated amorphous alumina.
12. The method of claim 1, wherein combining dawsonite or the dawsonite derivative with the catalytic active element comprises impregnating or disposing the catalytic active element on at least one surface of the dawsonite or the dawsonite derivative.
13. The method of claim 1, wherein combining dawsonite or the dawsonite derivative with the catalytic active element comprises doping the dawsonite or the dawsonite derivative with the catalytic active element.
14. The method of claim 13, wherein doping comprises exchanging the catalytic active element with a cation of the dawsonite.
15. The method of claim 1, wherein the catalytic active element comprises gallium, indium, rhodium, palladium, ruthenium, iridium, or combinations thereof.
16. The method of claim 1, wherein the catalytic active element comprises a transition metal selected from the group consisting of silver, platinum and gold.
17. The method of claim 1, wherein the catalytic active element is present in an amount of at least about 3 weight percent, based on the total weight of the catalyst composition.
18. The method of claim 1, further comprising heat treatment of the catalyst composition under conditions sufficient to calcine the catalyst composition.
19. The method of claim 1, further comprising disposing the catalyst composition on a monolithic substrate.
20. The method of claim 1, wherein the catalyst composition has a surface area in a range of about 200 m2gm to about 500 m2gm.
21. The method of claim 20, wherein the catalyst composition has a surface area in a range of about 300 m2gm to about 450 m2gm.
22. A method for making a catalyst composition for reducing nitrogen oxides, comprising the steps of:
(a) heat-treating dawsonite under conditions sufficient to convert the dawsonite to an amorphous alumina;
(b) treating the amorphous alumina in an aqueous medium at a temperature above the boiling point of the aqueous medium, so as to convert the amorphous alumina to a mesoporous alumina; and
(c) combining a catalytic active element with the mesoporous alumina, to form the catalyst composition.
23. A method for making a catalyst composition for reducing nitrogen oxides, comprising the steps of:
(a) heat treating dawsonite under conditions sufficient to calcine the dawsonite and convert dawsonite to an amorphous alumina,
(b) combining a catalytic active element with the amorphous alumina to form a catalytic active element-activated amorphous alumina, and
(c) treating the catalytic active element-activated amorphous alumina in an aqueous medium at a temperature above the boiling point of the aqueous medium, so as to convert the catalytic active element-activated amorphous alumina to a catalytic active element-activated mesoporous alumina, to form the catalyst composition.
24. A method for making a catalyst composition for reducing nitrogen oxides, comprising the steps of:
(a) combining a catalytic active element with dawsonite to form a catalytic active element-activated dawsonite,
(b) heat-treating the catalytic active element-activated dawsonite under conditions sufficient to calcine the dawsonite and convert the catalytic active element-activated dawsonite to a catalytic active element-activated amorphous alumina; and
(c) treating the catalytic active element-activated amorphous alumina in an aqueous medium at a temperature above the boiling point of the aqueous medium, so as to convert the catalytic active element-activated amorphous alumina to a catalytic active element-activated mesoporous alumina, to form the catalyst composition.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An active waveguide on a substrate comprising:
a waveguide core comprising:
a layer of monocrystalline silicon disposed on the substrate,
a layer of a first dielectric material on the layer of monocrystalline silicon, and
a slab of monocrystalline silicon on the layer of the first dielectric material, where the slab and a silicon body of a transistor are formed from the same monocrystalline silicon on the same substrate,
a cladding comprised of a plurality of dielectric materials,
where at least one of the plurality of dielectric materials is comprised of a salicide block layer used during the fabrication of a transistor,
a plurality of doped regions in the slab of monocrystalline silicon,
where at least one of the plurality of doped regions is doped at the same time with the same dopant as a doped region in the structure of a transistor on the same substrate,
a plurality of ohmic contacts, each of which is formed in a region of the plurality of doped regions in the slab of monocrystalline silicon,
where at least one of the plurality of ohmic contacts is formed at the same time with the same material as an ohmic contact in the structure of a transistor on the same substrate, and
a plurality of conductive plugs coupling each of the plurality of ohmic contacts to at least one of a plurality of metal layers of an integrated circuit, where at least one of the plurality of conductive plugs is formed at the same time with the same material as a conductive plug coupling an ohmic contact of a transistor on the same substrate with the same one of a plurality of metal layers.
2. The active waveguide of claim 1, wherein the substrate is comprised of a layer of silicon dioxide disposed on a layer of monocrystalline silicon.
3. The active waveguide of claim 2, wherein the substrate,
the layer of monocrystalline silicon disposed on the substrate,
the layer of dielectric material disposed on the layer of monocrystalline silicon and
the slab of monocrystalline silicon disposed on the layer of dielectric material, comprises a wafer.
4. The light scattering element of claim 1, wherein the layer of dielectric is comprised of silicon dioxide and is used to electrically isolate the transistor from the slab of monocrystalline silicon.
5. The light scattering element of claim 1, wherein the cladding includes a bottom cladding comprised of the top layer of the substrate.
6. The light scattering element of claim 1, wherein the cladding includes a layer of dielectric material formed at the same time as the sidewall passivation for the silicon body of a transistor.
7. The light scattering element of claim 1, wherein the cladding includes a plurality of layers of dielectric material formed at the same time as a plurality of dielectric materials used as a gate spacer for a transistor.
8. The light scattering element of claim 1, wherein the cladding includes a layer of dielectric material formed at the same time as a contact punch-through layer for a transistor.
9. The light scattering element of claim 1, wherein the cladding includes a layer of dielectric material formed at the same time as an inter-level dielectric for a transistor.
10. The light scattering element of claims 6, 7, 8 or 9, wherein the layer of dielectric material included in the cladding is selected from the group comprising: silicon dioxide, silicon oxynitride and silicon nitride.
11. The light scattering element of claim 1, wherein at least one of the plurality of dielectric materials is selected from a group of dielectrics used at the same time to form a dielectric element of a transistor,
where the group of dielectrics comprises: a contact punch-through layer, an inter-layer dielectric film, a gate spacer, a salicide block, a dielectric spacer, a sidewall passivation film, an isolation dielectric, an oxide spacer and a field oxide.
12. The light scattering element of claim 11, wherein thermal oxidation is used to form a sidewall passivation film,
where the sidewall passivation film is used as one of a plurality of dielectric materials for the optical waveguide and is formed at the same time as the sidewall passivation film for the body of a transistor.
13. The light scattering element of claim 1, wherein at least one of the plurality of dielectric materials is selected from the group comprising: SiO2, SiCOH, SiCOF, Si3N4, SiON, BPSG and silicon-based materials including one or more of the following elements: oxygen, carbon, nitrogen, hydrogen, boron, phosphorus, fluorine and arsenic.
14. The light scattering element of claim 1, wherein the transistor is selected from the group comprising: a CMOS transistor, a BiCMOS transistor, a bipolar junction transistor (BJT) and a junction FET (JFET) transistor.
15. The light scattering element of claim 1, wherein the salicide block layer is used as a gate spacer during the fabrication of a transistor on the same substrate.
16. The active waveguide of claim 1, wherein an ohmic contact is comprised of a metal silicide.
17. The active waveguide of claim 1, wherein a conductive plug is comprised of tungsten.
18. The active waveguide of claim 1, further comprising fabrication of a local interconnection between a pair of transistors, at the same time as fabricating a local interconnection for coupling an ohmic contact on the slab of monocrystalline silicon with an ohmic contact on a transistor.
19. The active waveguide of claim 18, wherein the local interconnection is comprised of a material selected from the group comprising: tungsten and aluminum.