Catalysts for petrochemical catalysis
Metal oxide catalysts comprising various dopants are provided. The catalysts are useful as heterogenous catalysts in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons such as ethane and ethylene. Related methods for use and manufacture of the same are also disclosed.
1. A catalytic material comprising a support or carrier and a catalyst comprising the following formula:
ABO 3 ;
wherein:
A is an element from the lanthanides or group 2, 3 or 4 of the periodic table;
B is an element from groups 4, 12 or 13 of the periodic table or Ce, Eu, Gd, Tb or Ho, and
O is oxygen,
the catalyst further comprising one or more dopant from any one of groups 2 or 3, and wherein the catalyst further comprises a methane conversion of greater than 20% and a C2 selectivity of greater than 50% when the catalyst is employed as a heterogeneous catalyst in the oxidative coupling of methane at a temperature ranging from about 550° C. to about 750° C., and provided that A and B are not the same.
2. The catalytic material of claim 1 , in the form of a formed aggregate.
3. The catalytic material of claim 1 , wherein the support or carrier comprises silicon, magnesium, yttrium, zirconium, lanthanum, hafnium, aluminum or gallium.
4. The catalytic material of claim 3 , wherein the support or carrier comprises SiO 2 , MgO, Y 2 O 3 , ZrO 2 , La 2 O 3 , HfO 2 , Al 2 O 3 or Ga 2 O 3 .
5. A method for the oxidative coupling of methane, the method comprising contacting methane with the catalytic material of claim 1 at temperatures ranging from about 550° C. to about 750° C., wherein the method comprises a methane conversion of greater than 20% and a C2 selectivity of greater than 50%.
6. The method of claim 5 , wherein the method produces a product gas comprising less than 0.5% carbon monoxide.
7. The catalytic material of claim 1 , wherein A is from groups 2, 3 or 4.
8. The catalytic material of claim 1 , wherein A is Ce, Pr, Sr, Ca, Mg, Y, Zr or Ba.
9. The catalytic material of claim 1 , wherein B is from group 4.
10. The catalytic material of claim 1 , wherein B is Zr or Hf.
11. The catalytic material of claim 1 , wherein the dopant is Sr, Mg or Ca.
12. The catalytic material of claim 1 , wherein the catalyst comprises one of the following formulas: Y/SrZrO 3 , SrHfO 3 , SrZrO 3 , Mg/SrHfO 3 , CaHfO 3 or SrTbO 3 .
13. The catalytic material of claim 1 , wherein the catalyst is a bulk catalyst.
14. The catalytic material of claim 1 , wherein the catalyst is a nanostructured catalyst.
15. The catalytic material of claim 14 , wherein the catalyst is a nanowire.