Fluid catalytic cracking catalyst

DETAILED DESCRIPTION We claim: 1.
A composition of matter as a component in catalytic cracking compositions which consists essentially of a composite of active alumina and 0.
5 to 1 weight percent bismuth as bismuth oxide prepared by forming a cogel of active alumina and a soluble bismuth salt, drying said gel and calcining the resulting composite at a temperature in the range of 1000.
degree.
to 1200.
degree.
F.
for at least one hour.
2.
A composition according to claim 1 wherein said composite contains from 0.
1 to 10 weight percent bismuth.
3.
A composition according to claim 1 wherein said composite contains from 0.
1 to 4 weight percent bismuth.
4.
A catalytic cracking catalyst composition comprising a major portion of a cracking catalyst composed of a crystalline zeolite in a supporting matrix in intimate admixture with a minor portion of a composite of bismuth oxide and active alumina, wherein said composite contains from 0.
05 to 25 weight percent bismuth, calculated as the metal.
5.
A catalytic cracking catalyst according to claim 4 wherein said composition contains 90 weight percent of said cracking catalyst and 10 weight percent of said composite of active alumina and bismuth oxides.
6.
A catalytic cracking catalyst according to claim 5 wherein said composite of bismuth oxide and alumina contains from 0.
1 to 4 weight percent bismuth.
7.
A catalytic cracking catalyst according to claim 5 wherein said composite contains 0.
5 to 1 weight percent bismuth.
8.
A catalytic cracking catalyst according to claim 4 wherein the cracking catalyst composition comprises platinum or a platinum compound.
9.
A composition of matter as a component in catalytic cracking compositions consisting essentially of alumina and bismuth and containing 0.
05 to 25 weight percent bismuth prepared by forming a cojel of alumina and a soluble bismuth salt, drying the gel and calcining the resulting composite at a temperature in the range of 1000.
degree.
to 1200.
degree.
F.
for at least one hour.
10.
A composition of matter according to claim 9 wherein said cojel is prepared by dissolving alumina in a nitric acid solution of bismuth nitrate