초록 ▼

A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a hi

A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

대표청구항 ▼

The invention claimed is: 1. A catalyst element for a gas turbine engine comprising: a metal substrate; an outer layer of ceramic thermal barrier coating material disposed over the metal substrate, the ceramic thermal barrier coating material effective to thermally insulate the metal substrate from

The invention claimed is: 1. A catalyst element for a gas turbine engine comprising: a metal substrate; an outer layer of ceramic thermal barrier coating material disposed over the metal substrate, the ceramic thermal barrier coating material effective to thermally insulate the metal substrate from a high temperature fuel/air mixture; and the ceramic thermal barrier coating material comprising a base compound comprising a crystal structure populated with base elements and further comprising selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions wherein the ceramic thermal barrier coating material comprises a structure selected from the group consisting of: a pyrochlore structure represented by the formula A2-xMxB2O7 (0<x<1), where A is a 3+ cation, B is a 4+ cation, and where M is any 3+ rare earth element other than A or 3+ cation smaller than A; a pyrochlore structure represented by the formula A2-xMxB2O7 (0<x<1), where A is a 3+ cation, B is a 4+ cation, and where M is a 2+ cation selected the group consisting of Ca, Mg, Sr, and Ba; a pyrochlore structure represented by the formula A2B2-xMxO7 (0<x<1), where A is a 3+ cation, B is a 4+ cation, and where M is Al or Sc; a pyrochlore structure represented by the formula A2B2-xMxO7 (0<x<1), where A is a 3+ cation, B is a 4+ cation, and where M is Ta or Nb; a garnet structure represented by the formula Y3-xMxB5O15 (0<x<3), where B is a 3+ cation, and where M is a rare earth element other than A; a garnet structure represented by the formula Y3-xMxB5O15 (0<x<3), where B is a 3+ cation, and where M is Ga or Sc; a garnet structure represented by the formula Y3Al5-xMxO15 (0<x<5), where M is Ga or Sc; a garnet structure represented by Y3Al5-xFexO15 (0<x<2); a garnet structure represented by Y3Al5-xMxO15 (0<x<2), where M is Mn or Ti; and a spinel structure represented by MgAl2-xMxO15 (0<x<1), where M is Mn or Ti. 2. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material further comprises a pyrochlore structure represented by the formula Y2O3--ZrO2--TiO2. 3. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the pyrochlore structure represented by the formula A2-xMxB2O7 (0<x<1), where A is a 3+ cation, B is a 4+ cation, and where M is any 3+ rare earth element other than A or 3+ cation smaller than A. 4. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the pyrochlore structure represented by the formula A2-xMxB2O7 (0<x<1), where A is a 3+ cation, B is a 4+ cation, and where M is a 2+ cation selected from the group consisting of Ca, Mg, Sr, and Ba. 5. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the pyrochlore structure represented by the formula A2B2-xMxO7 (0<x<1), where A is a 3+ cation, B is a 4+ cation, and where M is Al or Sc. 6. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the pyrochlore structure represented by the formula A2B2-xMxO7 (0<x<1), where A is a 3+ cation, B is a 4+ cation, and where M is Ta or Nb. 7. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the garnet structure represented by the formula Y3-xMxB5O15 (0<x<3), where B is a 3+ cation, and where M is a rare earth element other than A. 8. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the garnet structure represented by the formula Y3-xMxB5O15 (0<x<3), where B is a 3+ cation, and where M is Ga or Sc. 9. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the garnet structure represented by the formula Y3Al5-xMxO15 (0<x<5), where M is Ga or Sc. 10. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the garnet structure represented by Y3Al5-xFexO15 (0<x<2). 11. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the garnet structure represented by Y3Al5-xMxO15 (0<x<2) where M is Mn or Ti. 12. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material comprises the spinel structure represented by MgAl2-xMxO15 (0<x<1) where M is Mn or Ti. 13. The catalyst element of claim 1, further comprising precious metal crystallites disposed within the crystal structure to a loading of 3-30 mg/in2 and effective to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites. 14. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material is deposited by a plasma spray process with a layered structure exhibiting an effective SSA value of greater than 30 m2/g. 15. The catalyst element of claim 1, wherein the ceramic thermal barrier coating material is deposited by a vapor deposition process to achieve a columnar grained structure exhibiting an SSA value of greater than 30 m2/g. 16. The catalyst element of claim 15, further comprising the columnar grained structure exhibiting an SSA value of between 50-150 m2/g. 17. The catalyst element of claim 15, further comprising the columnar grained structure exhibiting an SSA value of between 100-150 m2/g.