Catalyst for alkane oxidative dehydrogenation and/or alkene oxidation
The invention relates to a process for preparing a catalyst for alkane oxidative dehydrogenation and/or alkene oxidation, which catalyst is a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium, wherein the process comprises: a) preparing a catalyst precursor containing molybdenum, vanadium, niobium and optionally tellurium; b) optionally contacting the catalyst precursor obtained in step a) with oxygen and/or an inert gas at an elevated temperature; c) contacting the catalyst precursor obtained in step a) or step b) with a gas mixture comprising ammonia and water, which gas mixture further comprises oxygen and/or an inert gas, at an elevated temperature; and d) optionally contacting the catalyst precursor obtained in step c) with an inert gas at an elevated temperature. Further, the invention relates to a catalyst obtainable by said process and to a process of the oxidative dehydrogenation of an alkane containing 2 to 6 carbon atoms and/or the oxidation of an alkene containing 2 to 6 carbon atoms wherein said catalyst is used.
1. A process for preparing a catalyst for alkane oxidative dehydrogenation and/or alkene oxidation, which catalyst is a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium, wherein the process comprises:
a) preparing a catalyst precursor containing molybdenum, vanadium, niobium and optionally tellurium;
b) optionally contacting the catalyst precursor obtained in step a) with oxygen and/or an inert gas at an elevated temperature;
c) contacting the catalyst precursor obtained in step a) or step b) with a gas mixture comprising ammonia and water, which gas mixture further comprises oxygen and/or an inert gas, at an elevated temperature which is of from 120 to 900° C.; and
d) contacting the catalyst precursor obtained in step c) with an inert gas at an elevated temperature which is at least higher than 420° C.
2. The process according to claim 1 , wherein in step b) the temperature is of from 120 to 500° C.
3. The process according to claim 1 , wherein in step c) the temperature is of from 150 to 700° C.
4. The process according to claim 1 , wherein in step d) the temperature is of from higher than 420 to 900° C.
5. The process according to claim 1 , wherein the gas mixture in step c) comprises 0.01 to 10 vol. % of ammonia, based on the total volume of the gas mixture.
6. The process according to claim 1 , wherein the gas mixture in step c) comprises 1 to 50 vol. % of water, based on the total volume of the gas mixture.
7. A catalyst obtained by the process according to claim 1 .
8. A process of the oxidative dehydrogenation of an alkane containing 2 to 6 carbon atoms and/or the oxidation of an alkene containing 2 to 6 carbon atoms, said process comprising, contacting the catalyst obtained by the process according to claim 1 , with the alkane and/or the alkene.
9. The process according to claim 8 , wherein the alkane is ethane or propane and the alkene is ethylene or propylene.