Substrate and a method of manufacturing a substrate

1. A catalytic convertor comprising:

a substrate body including a first surface, a second surface located opposite the first surface, and a plurality of microchannels including openings on the first surface, each microchannel of the plurality extending in a same direction toward the second surface as all other microchannels of the plurality and of the substrate body, the substrate body arranged within the catalytic convertor such that a principal flow of fluid through the catalytic convertor flows along the first surface of the substrate body,

wherein:

the substrate body and at least a portion of the first surface comprises a catalytically active material;

the openings having widths falling in the range 5 μm to 200 μm;

the substrate body is in the form of a sheet; and

the sheet has a thickness and the microchannels extend at least 80% of the sheet thickness.

2. The catalytic convertor of claim 1 comprising a plurality of surface structures protruding from the outer surface of the substrate body.

3. The catalytic convertor of claim 1 wherein at least a portion of the substrate body has a textured surface.

4. The catalytic convertor of claim 1 comprising a plurality of sheets of substrate.

5. The catalytic convertor of claim 4 , further comprising a plurality of spacers for supporting the plurality of sheets in a spaced arrangement.

6. The catalytic convertor of claim 5 , wherein the spacers are formed integrally with the sheets.

7. The catalytic convertor of claim 4 , wherein the plurality of sheets are arranged to extend substantially in parallel.

8. The catalytic convertor of claim 4 , wherein the plurality of sheets are spaced by one to three times the width of the sheets.

9. The catalytic convertor of claim 1 , wherein the substrate comprises ceramic.

10. The catalytic converter of claim 1 , wherein the substrate comprises one or more of cordierite; zirconia; yttrium stabilised zirconia; titania; silicon carbide; clay; alumina; stainless steel, FeCr alloys; alloys of iron; alloys of aluminium; or sintered metals.

11. The catalytic converter of claim 1 , wherein the micro-channels have an entrance diameter of 20 μm to 70 μm.

12. The catalytic convertor of claim 1 , wherein the substrate body is formed of a material comprising the catalytically active material.

13. The catalytic convertor of claim 1 , wherein the substrate body or at least one major surface of the sheet is coated with a catalytically active coating.

14. The catalytic convertor of claim 1 wherein said sheet is curved in the form of a spiral.

15. The catalytic convertor of claim 1 , the catalytically active material including a platinum group metal.

16. The catalytic convertor of claim 1 , wherein said second surface is a solid surface.

17. The catalytic convertor of claim 1 , the plurality of micro-channels being substantially uniform channels.

18. A catalytic convertor substrate having a plurality of microchannels each extending in a same direction from a first surface toward a second surface as all other microchannels of the plurality and of the substrate body, each microchannel has an opening having widths falling in the range 5 μm to 200 μm on the first surface formed by providing a suspension containing a substrate material in particulate form and a polymer in a first solvent, the substrate material comprises a catalytically active material;

introducing the suspension into a mould or extruding the suspension;

contacting the suspension with a second solvent to remove at least some of the first solvent from the suspension and thereby form a green body having the micro-channels and said polymer;

removing at least a portion of a surface layer of said green body;

sintering the green body;

forming the green body into a sheet having a thickness; and

forming the micro-channels to extend at least 80% of the sheet thickness.

19. The method of claim 18 , wherein the sintering is conducted before the removing.

20. A catalytic convertor comprising:

a substrate body arranged within the catalytic convertor such that a principal flow of fluid through the catalytic convertor flows along a first surface of the substrate body,

wherein:

the substrate body comprises a catalytically active material, a second surface located opposite that of the first surface, and a plurality of microchannels, each microchannel being substantially uniform extending in a same direction toward the second surface from the first surface; as all other microchannels of the plurality and of the substrate body,

said first surface of the substrate body has a plurality of openings to the micro-channels, the openings having widths falling in the range 5 μm to 200 μm; and at least a portion of said surface comprises a catalytically active coating;

the substrate body is in the form of a sheet having a thickness; and

the micro-channels extend at least 80% of the sheet thickness.