Methods for producing multifunctional catalysts for upgrading pyrolysis oil
A method of making a multifunctional catalyst for upgrading pyrolysis oil includes contacting a zeolite support with a solution including at least a first metal catalyst precursor and a second metal catalyst precursor, the first metal catalyst precursor, the second metal catalyst precursor, or both, including a heteropolyacid. Contacting the zeolite support with the solution deposits or adsorbs the first metal catalyst precursor and the second catalyst precursor onto outer surfaces and pore surfaces of the zeolite support to produce a multifunctional catalyst precursor. The method further includes removing excess solution from the multifunctional catalyst precursor and calcining the multifunctional catalyst precursor to produce the multifunctional catalyst comprising at least a first metal catalyst and a second metal catalyst deposited on the outer surfaces and pore surfaces of the zeolite support.
1. A method of making a multifunctional catalyst for upgrading pyrolysis oil, the method comprising:
contacting a zeolite support with a solution comprising at least a first metal catalyst precursor and a second metal catalyst precursor, where the first metal catalyst precursor, the second metal catalyst precursor, or both, comprises a heteropolyacid having at least one heteroatom selected from the group consisting of phosphorous, silicon, germanium, arsenic, and combinations of these, where the zeolite support comprises a molar ratio of silica to alumina of from 10 to 70, and where the contacting deposits the first metal catalyst precursor and the second metal catalyst precursor onto outer surfaces and pore surfaces of the zeolite support to produce a multifunctional catalyst precursor;
removing excess solution from the multifunctional catalyst precursor; and
calcining the multifunctional catalyst precursor at a temperature of at least 500 degrees Celsius to produce the multifunctional catalyst comprising at least a first metal catalyst and a second metal catalyst deposited on the outer surfaces and pore surfaces of the zeolite support, and
where the multifunctional catalyst has an acidity of less than 10,000 micromoles of ammonia per gram (μmol(NH 3 )/g).
2. The method of claim 1 , in which the heteropolyacid comprises at least one metal selected from cobalt, molybdenum, vanadium, or combinations of these.
3. The method of claim 1 , in which the first metal catalyst precursor comprises a first heteropolyacid and the second metal catalyst precursor comprises a second heteropolyacid that is different from the first heteropolyacid.
4. The method of claim 1 , in which the heteropolyacid comprises phosphomolybdic heteropolyacid having formula H 3 PMo 12 O 40 .
5. The method of claim 1 , further comprising dehydrating the heteropolyacid prior to contacting the zeolite support with the solution.
6. The method of claim 1 , in which the multifunctional catalyst precursor is calcined at a temperature of from 500 degrees Celsius to 600 degrees Celsius and for a time of from 4 hour to 6 hours to produce the multifunctional catalyst.
7. The method of claim 1 , in which the zeolite support comprises a nano beta zeolite having an average pore size of less than or equal to 2 micrometers.
8. The method of claim 1 , where the contacting causes the first metal catalyst precursor and the second metal catalyst precursor to be adsorbed directly onto the outer surfaces and pore surfaces of the zeolite support to produce the multifunctional catalyst precursor.
9. The method of claim 1 , where the heteropolyacid has a Keggin structure having general formula XM 12 O 40 n− or a Dawson structure having the general formula XM 18 O 82 n− , in which X is the heteroatom; M is molybdenum and optionally one or more of cobalt, vanadium, or a combination of these; and n− is an integer indicative of the charge of the anion of the heteropolyacid.
10. The method of claim 1 , where the solution consists essentially of the first metal precursor, the second metal precursor, a solvent, and, optionally, a phosphorous-containing compound.
11. The method of claim 10 , where the solution comprises the phosphorous-containing compound and the phosphorous-containing compound comprises phosphoric acid or phosphorous acid.
12. The method of claim 1 , in which the heteropolyacid comprises phosphomolybdic heteropolyacid (H 3 PMo 12 O 40 ), silicomolybdic heteropolyacid (H 4 SiMo 12 O 40 ), decamolybdiccobaltate heteropolyacid (H 6 [Co 2 Mo 10 O 38 H 4 ]), H 4 [PCoMo 11 O 40 ], H 4 [PVMo 11 O 40 ], H 5 [PV 2 Mo 10 O 40 ], H 7 [PV 4 Mo 8 O 40 ], H 9 [PV 6 Mo 6 O 40 ], H 3 [AsMo 12 O 40 ], H 4 [AsCoMo 11 O 40 ], H 5 [AsCo 2 Mo 10 O 40 ], H 4 [AsVMo 11 O 40 ], H 5 [AsV 2 Mo 10 O 40 ], H 7 [AsV 4 Mo 8 O 40 ], H 9 [AsV 6 Mo 6 O 40 ], H 5 [SiCoMo 11 O 40 ], H 6 [SiCo 2 Mo 10 O 40 ], H 5 [SiVMo 11 O 40 ], H 6 [SiV 2 Mo 10 O 40 ], H 10 [SiV 6 Mo 6 O 40 ], H 6 [P 2 Mo 18 O 82 ], or combinations of these.
13. The method of claim 1 , in which the solution includes from 1 weight percent (wt. %) to 20 wt. % of the first metal catalyst precursor.
14. The method of claim 1 , in which the solution includes from 1 wt. % to 20 wt. % of the second metal catalyst precursor.
15. The method of claim 1 , in which the solution does not include an organic compound.
16. The method of claim 1 , in which the first metal of the first metal precursor consists of molybdenum.
17. The method of claim 1 , in which the second metal of the second metal precursor consists of cobalt.
18. The method of claim 1 , in which the multifunctional catalyst has an acidity of from 1000 μmol(NH 3 )/g to 5000 μmol(NH 3 )/g.
19. The method of claim 1 , in which the multifunctional catalyst does not include a binder or a matrix.
20. The method of claim 1 , where the multifunctional catalyst precursor consists of the zeolite support, the first metal catalyst precursor, the second metal catalyst precursor, and water.