Compound having a pyrochlore-structure and its use as a catalyst carrier in water gas shift reaction
A compound of formula (Na 0.33 A 0.66 ) 2 B 2 O 7-δ wherein A is one or more metals chosen from the lanthanide metals; B is one or more metals chosen from Ti, Sn, Ge, Ru, Mn, Ir, Os and Pb; and δ is a number in the range 0-1 is disclosed. Water gas shift catalysts comprising precious metals such as gold dispersed on the (Na 0.33 A 0.66 ) 2 B 2 O 7-δ compound are also disclosed.
1. A catalyst comprising a metal dispersed on a support material, wherein the support material is a compound of formula
(Na 0.33 A 0.66 ) 2 B 2 O 7-δ
wherein A is one or more lanthanide metals; B is one or more metals selected from the group consisting of Ti, Sn, Ge, Ru, Mn, Ir, Os and Pb; and δ is a number in the range 0-1.
2. A catalyst according to claim 1 , wherein the metal dispersed on the support material comprises a precious metal.
3. A catalyst according to claim 2 , wherein the precious metal dispersed on the support material is selected from the list consisting of gold and an alloy of gold.
4. A water gas shift process comprising the step of passing water and carbon monoxide over a catalyst according to claim 1 .
5. A catalyst according to claim 1 , wherein A is one or more lanthanide metals selected from the group consisting of Ce, Pr and Tb.
6. A catalyst according to claim 1 , wherein A is more than one lanthanide metal, and at least 70 atomic percent of A is Ce.
7. A catalyst according to claim 1 , wherein A is Ce.
8. A catalyst according to claim 1 , wherein B is Ti.
9. A catalyst according to claim 1 , wherein B is Ti and Sn.
10. A catalyst according to claim 1 , wherein B is Ti and Ge.
11. A catalyst according to claim 1 , wherein δ is 0.
12. A catalyst according to claim 1 , wherein the formula is (Na 0.33 Ce 0.66 ) 2 Ti 2 O 7 .