Heteroatom-doped zeolites for bifunctional catalytic applications
Provided herein are methods for hydroisomerization of a hydrocarbon feedstock comprising contacting the hydrocarbon feedstock with hydrogen and a catalyst to yield a hydrocarbon product having an increase in branched hydrocarbons relative to the hydrocarbon feedstock. The present catalysts comprise a heteroatom-doped Beta zeolite having a trivalent cation as a framework metal oxide, an extra-framework species comprised of cerium and/or cobalt, and from 0.01 to 1.5 wt. % of a group VIII or VIB metal, or a combination thereof.
1 . A method of synthesizing a heteroatom doped-Beta zeolite comprising oligomeric cerium oxide and/or oligomeric cobalt oxide as an extra-framework species, the method comprising crystalizing a reaction mixture comprising water, SiO 2 , a framework metal oxide, wherein the reaction mixture comprises:
a molar ratio of structure directing agent cation, Q, to SiO 2 in the reaction mixture of 0 to 4;
a molar ratio of SiO 2 to framework metal oxide in said reaction mixture of greater than 10;
a molar ratio of water to SiO 2 in the reaction mixture of greater than 0;
a molar ratio of alkali metal M to SiO 2 in the reaction mixture of from 0 to 1; and
a molar ratio of SiO 2 to Al source in the reaction mixture of greater than 5,
the method further comprising adding about 0.01 to about 1.5 wt % Pt to the heteroatom doped-Beta zeolite.
2 . The method of claim 1 , wherein the reaction mixture further comprises a structure directing agent.
3 . The method of claim 1 , wherein the reaction mixture further comprises a mineralizer.
4 . The method of claim 1 , further comprising the step of calcinating the heteroatom-doped Beta zeolite at a temperature from about 100° C. to about 800° C., under inert, oxidative and/or steaming conditions.
5 . A composition comprising a Beta zeolite having extra-framework species of oligomeric cerium oxide and/or oligomeric cobalt oxide, and from about 0.01 to about 1.5 wt. % of Pt.
6 . The composition of claim 5 , wherein the Beta zeolite comprises a molar ratio of SiO 2 to the extra-framework oligomeric cerium oxide and/or oligomeric cobalt oxide of greater than 10.
7 . The composition of claim 5 , wherein the Beta zeolite further comprises a molar ratio of SiO 2 to Al 2 O 3 of greater than 8.