Intermetallic catalysts

Claim 2

A catalyst comprising a substrate having deposited thereon a first coating containing a refractory metal oxide and having deposited upon the said oxide one or more intermetallic compounds of the general formula A x B y where A is selected from the group consisting of Ru, Rh, Pd, Ir and Pt, and B is selected from the group consisting of Al, Sc, Y, the lanthanides, Ti, Zr, Hf, V, Nb, and Ta, and where x and y are integral and may have values of 1 or more.

Claim 3

A catalyst according to claim 1 wherein the substrate is metallic.

Claim 4

A catalyst according to claim 2 wherein the metallic substrate is made from an alloy containing nickel and chromium having an aggregate nickel and chromium content greater than 20 wt.%.

Claim 5

A catalyst according to claim 2 wherein the metallic substrate is made from an iron alloy including at least one of the following elements: ______________________________________ Chromium 3-40 wt %; aluminium 1-10 wt %; -cobalt trace to 5 wt %; nickel trace - 72 wt %, and carbon trace - 0.5 wt %. ______________________________________

Claim 6

A catalyst according to claim 4 wherein the metallic substrate includes at least one of the following elements present from a trace to the following weight percentage: ______________________________________ Silicon 0.2 Manganese 0.2 zirconium 0.01 copper 0.01 niobium 0.1 tantalum 0.8 titanium 0.8 cerium 0.01 and calcium 0.01. ______________________________________

Claim 7

A catalyst according to claim 2 wherein the metallic substrate comprises 0.5 to 12 wt % aluminium, 0.1 to 3.0 wt % yttrium, 0 to 20 wt % chromium and balance iron.

Claim 8

A catalyst according to claim 2 wherein the metallic substrate comprises 0.5 to 4 wt % aluminium, 0.5 to 3.0 wt % yttrium, 20 to 95 wt % chromium and balance iron.

Claim 9

A catalyst according to claim 1 wherein the substrate is made from a ceramic material.

Claim 10

A catalyst according to claim 8 wherein the substrate is monolithic and is made from a material selected from the groups consisting of zircon-mullite, mullite, alpha-alumina, silli-manite, magnesium silicates, zircon petalite, spodumene, cordierite and alumino-silicates.

Claim 11

A catalyst according to claim 8 wherein the substrate is in the form of pellets and is made from a material selected from the group consisting of granular charcoal, alpha or gamma alumina granules or pellets, naturally occurring or synthetic alumino-silicates, magnesia, diatomaceous earth, bauxite, titania, zirconia, limestone, magnesium silicate, silicon carbide, activated and inactivated carbons.

Claim 12

A catalyst according to claim 1 wherein the first coating comprises at least one oxide of a metal selected from the group of metals consisting of B, Al, Si, Be, Mg, Ca, Sr, Ba, Sc, Y, Ti, Zr, Hf, the lanthanides and the actinides.

Claim 13

A catalyst according to claim 1 wherein the intermetallic compound A x B y is selected from the group consisting of Ti Pt 3 , ZrPt 3 , HfPt 3 , YPd 3 , LnPd, LnPd 3 and Ln 5 Pd 2 (where Ln=Sm, Gd, Dy, Ho, and Er), HfIr 3 , TaIr 3 , NbI 3 HfIr, TaPd TiRu, ZrRu, NbIr, TaRh 3 , VIr 3 and CeRu 2 .