1. A supported catalyst comprising a catalytic nickel-rhodium alloy, a support structure and at least one other metal selected from the group consisting of lanthanide elements, zirconium, manganese and magnesium, said catalyst having activity for catalyzing the partial oxidation of methane to synthesis gas under partial oxidation promoting conditions in a short contact time reactor.
2. The catalyst of claim 1 comprising about 1-50 weight percent nickel and about 0.01-10 weight percent rhodium.
3. The catalyst of claim 1 wherein said support structure comprises a substance chosen from the group consisting of spinels, perovskites, magnesium oxide, pyrochlores, brownmillerites, zirconium phosphate, magnesium stabilized zirconia, zirconia stabilized alumina, silicon carbide, yttrium stabilized zirconia, calcium stabilized zirconia, yttrium aluminum garnet, alumina, cordierite, ZrO2, MgAl2O4, SiO2 and TiO2, said rhodium and nickel being disposed on said support structure.
4. The catalyst of claim 3 wherein said support structure comprises a substance chosen from group consisting of spinels, perovskites, pyrochlores and brownmillerites.
5. The catalyst of claim 3 wherein said substance is a refractory oxide.
6. The catalyst of claim 1 wherein said support structure comprises a foam structure.
7. The catalyst of claim 6 wherein said foam structure comprises about 12-60 pores per centimeter of structure.
8. The catalyst of claim 5 wherein said support structure comprises a honeycomb monolith structure.
9. The catalyst of claim 1 comprising 1 wt % rhodium, 3 wt % manganese and 13 wt % nickel on a MgAl2O4 support structure.
10. The catalyst of claim 1 comprising 1 wt % rhodium and LaZr0.5Ni0.5O3.
11. The catalyst of claim 1 comprising Rh0.02Ni0.03Mg0.9O.
12. The catalyst of claim 1 comprising rhodium, nickel and cobalt on a support structure comprising ZrO2.
13. The catalyst of claim 1 comprising rhodium and nickel on a support structure comprising Al2O3.
14. The catalyst of claim 13 comprising 1% rhodium, 10.9% nickel and 8.6% magnesium on a support structure comprising 99% Al2O3.
15. The supported catalyst of claim 1 wherein said at least one other metal comprises a lanthanide element.
16. The supported catalyst of claim 15 wherein said lanthanide element comprises lanthanum.
17. The supported catalyst of claim 1 wherein said a least one other metal comprises zirconium.
18. The supported catalyst of claim 1 wherein said at least one other metal comprises manganese.
19. The supported catalyst of claim 1 wherein said at least one other metal comprises magnesium.
20. The supported catalyst of claim 1 wherein said support structure comprises a monolith.
21. The supported catalyst of claim 1 wherein said support structure comprises a refractory metal oxide.
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. A field-effect semiconductor device comprising a semiconductor body having a plurality of side-by-side device cells at one major surface of the body, wherein each device cell has a source region that is separated by a channel-accommodating region of a first conductivity type from an underlying drain region of an opposite, second conductivity type, a gate electrode is capacitively coupled to the channel-accommodating region to control a conduction channel between the source and drain regions, and the device has at least one drain connection that extends in a drain trench from the one major surface to the underlying drain region, characterised in that the channel-accommodating region extends laterally to the drain trench, the drain trench extends through the thickness of the channel-accommodating region to the underlying drain region, and the drain connection is separated from the channel-accommodating region by an intermediate insulating layer on side-walls of the drain trench.
2. A device as claimed in claim 1, further characterised in that the drain trench extends through a cell comprising a source region that is laterally separated from the drain trench by an intermediate part of the channel-accommodating region, which intermediate part of the channel-accommodating region is outside the control of the gate electrode.
3. A device as claimed in claim 2, further characterised in that the drain trench and the gate electrode are interdigitated in their layout.
4. A device as claimed in claim 1, further characterised in that the drain trench extends through a connection cell that is laterally surrounded by device cells without a drain trench.
5. A device as claimed in claim 4, further characterised in that the connection cell comprises a source region which is laterally separated from the drain trench by an intermediate part of the channel-accommodating region that is outside the control of the gate electrode.
6. A device as claimed in any one of claims 1 to 5, further characterised in that the gate electrode extends in a gate trench through the thickness of the channel-accommodating region, and the source region of each cell is adjacent to the gate trench at the one major surface.
7. A device as claimed in claim 6, further characterised in that the gate trench is lined with a gate dielectric layer that is thinner adjacent to the channel-accommodating region than is the intermediate insulating layer of the drain trench.
8. A device as claimed in any one of the preceding claims, further characterised in that the drain region comprises a more highly doped electrode region underlying a less highly doped drift region, and the drain connection in the drain trench extends through the thickness of both the channel-accommodating region and the drain drift region to reach the more highly doped drain electrode region.
9. A device as claimed in claim 8, further characterised in that the drain drift region has a dopant concentration of the second conductivity type that is less than the conductivity-type-determining dopant concentration of the first conductivity type of the channel-accommodating region.
10. A device as claimed in any one of claims 1 to 7, further characterised in that, adjacent to the channel-accommodating region, the drain region has a dopant concentration of the second conductivity type that is higher than the conductivity-type-determining dopant concentration of the first conductivity type of the channel-accommodating region.
11. A device as claimed in any one of the preceding claims, further characterised in that the drain region comprises a monocrystalline substrate of the second conductivity type, and the channel-accommodating region is present in an epitaxial layer on the monocystalline substrate.