Stabilized alumina supports, catalysts made therefrom, and their use in partial oxidation

A method for making a thermally stable aluminum-based catalyst support comprising:

• (a) impregnating a solution of a rare earth metal onto an aluminum-containing precursor;
• (b) drying the impregnated aluminum-containing precursor;
• and
• (c) calcining at a temperature between 1,000° C. and 1,600° C. in a manner effective to convert a portion of said aluminum-containing precursor to an aluminum oxide phase comprising alpha-alumina, theta-alumina, or combinations thereof, and to convert another portion of said aluminum-containing precursor with at least a fraction of said rare earth metal to a rare earth aluminate of a hexaaluminate or hexaaluminate-like structure with a high molar ratio of aluminum to rare earth metal between 11:1 and 14:1, and further to a second rare earth aluminate of a perovskite or perovskite-like structure with a low molar ratio of aluminum to rare earth metal of less than 2:1,
• such that the catalyst support comprises said rare earth aluminate with the low molar ratio of aluminum to rare-earth metal;
• the aluminum oxide phase comprising less than 20 wt % of alpha-alumina;
• and less than 100 wt % to about 1 wt % of said rare earth aluminate with the high molar ratio of aluminum to rare earth metal.

A partial oxidation catalyst comprising:

• (a) an active ingredient comprising a rhodium alloy or a metal selected from the group consisting of rhodium, iridium, ruthenium and combinations thereof, wherein, when the active ingredient comprises rhodium, said rhodium being is in an amount of from about 0.1 wt % to about 20 wt % based on the total catalyst weight;
• and
• (b) a support onto which the active ingredient is dispersed, said support comprising
• an alumina phase selected from the group consisting of alpha-alumina, theta-alumina and combinations thereof;
• a rare earth aluminate of a hexaaluminate or hexaaluminate-like structure comprising a rare-earth metal and having a high molar ratio of aluminum to rare earth metal between 11:1 and 14:1;
• and
• a rare earth aluminate of a perovskite or perovskite-like structure comprising the rare-earth metal and having a low molar ratio of aluminum to rare earth metal of less than 2:1,
• wherein the support comprises less than 100 wt % to about 1 wt % of said rare earth aluminate with the high molar ratio of aluminum to rare earth metal based on the total weight of the support.

A method for making synthesis gas comprising:

• converting a gaseous hydrocarbon stream and an oxygen-containing stream over a partial oxidation catalyst, to make a product stream comprising CO and H2,
• wherein said partial oxidation catalyst includes
• an active ingredient comprising a rhodium alloy or a metal selected from the group consisting of rhodium, iridium, ruthenium, and combinations thereof, wherein, when the active ingredient comprises rhodium, said rhodium is in an amount of from about 0.1 wt % to about 20 wt % based on the total catalyst weight;
• and
• a support onto which the active ingredient is dispersed, said support comprising
• an alumina phase selected from the group consisting of alpha-alumina, theta-alumina and combinations thereof;
• a rare earth aluminate of a hexaaluminate or hexaaluminate-like structure comprising a rare earth metal and having a high molar ratio of aluminum to rare earth metal between 11:1 and 14:1;
• and
• a rare earth aluminate of a perovskite or perovskite-like structure comprising the rare-earth metal and having a low molar ratio of aluminum to rare earth metal of less than 2:1;
• wherein the support comprises less than 100 percent to about 1 percent by weight of said rare earth aluminate with the high molar ratio of aluminum to rare earth metal based on the total weight of the support.

A partial oxidation catalyst comprising:

• (a) an active ingredient comprising rhodium or a rhodium alloy, said rhodium alloy comprising rhodium and a metal selected from the group consisting of ruthenium, iridium, platinum, palladium, tantalum, niobium, molybdenum, rhenium, tungsten, cobalt, and zirconium, said rhodium being in an amount of from 0.1 wt % to about 20 wt % based on the total catalyst weight;
• and
• (b) a support onto which the active ingredient is dispersed, said support comprising:
• an alpha-alumina phase;
• less than 100 percent to about 1 percent by weight of a rare earth aluminate of a hexaaluminate or hexaaluminate-like structure, with a high molar ratio of aluminum to rare-earth metal between 11:1 and 14:1, and comprising at least one rare earth metal selected from the group consisting of lanthanum, neodymium, praseodymium, samarium, and combinations thereof, and
• a rare earth aluminate of a perovskite structure comprising the at least one rare earth metal with a low molar ratio of aluminum to rare-earth metal of less than 2:1.