Catalysts for dry reforming and methods of producing the same
The disclosure relates to catalysts for dry reforming, methods of producing the catalysts, and methods of using the catalysts in dry reforming. The catalysts contain nickel, molybdenum and a metal oxide. The methods of producing the catalysts include adding a solvent to precipitate the catalyst, followed by removing the solvent. The solvent addition and removal steps can be repeated as desired.
1 . A method, comprising:
a) combining a nickel precursor, a molybdenum precursor and a metal oxide in a first solvent to provide a mixture;
b) adding a second solvent to the mixture to precipitate a catalyst from the mixture, wherein the precipitated catalyst forms a first layer and the first solvent and the second solvent form a second layer; and
c) removing the second layer,
wherein the catalyst comprises nickel, molybdenum and the metal oxide; and
wherein the second solvent comprises a member selected from the group consisting of acetone, toluene, ethanol, ethyl acetate, propanol, butanol, methanol, dichloromethane, and acetonitrile.
2 . The method of claim 1 , further comprising repeating b) and c) at least three times.
3 . The method of claim 1 , wherein the second solvent comprises ethanol.
4 . The method of claim 1 , further comprising, after c), isolating the catalyst from the first solvent; and drying the isolated catalyst.
5 . The method of claim 1 , wherein:
the nickel precursor comprises a member selected from the group consisting of NiCl 2 , NiCl 2 ·6H 2 O, Ni(NO 3 ) 2 , NiSO 4 , Ni(NH 4 ) 2 , Ni(SO 4 ) 2 ·6H 2 O, Ni(OCOCH 3 ) 2 ·4H 2 O, NiBr 2 , NiCO 3 , NiF 2 , NiI 2 , NiC 2 O 4 ·2H 2 O and Ni(ClO 4 ) 2 ·6H 2 O; and
the molybdenum precursor comprises a member selected from the group consisting of Mo(CO) 6 , MoO 3 , Na 2 MoO 4 , CaMoO 4 , ZnMoO 4 and (NH 4 ) 6 Mo 7 O 2 ·4H 2 O.
6 . The method of claim 5 , wherein the metal oxide comprises a member selected from the group consisting of ZrO 2 , MgO, TiO 2 , Al 2 O 3 , SiO 2 , CrO 2 , Fe 2 O 3 , Fe 3 O 4 , CuO, ZnO, CaO, Sb 2 O 4 , Co 3 O 4 , Fe 3 O 4 , Pb 3 O 4 , Mn 3 O 4 , Ag 2 O 2 , U 3 O 8 , Cu 2 O, Li 2 O, Rb 2 O, Ag 2 O, Tl 2 O, BeO, CdO, TiO, GeO 2 , HfO 2 , PbO 2 , MnO 2 , TeO 2 , SnO 2 , La 2 O 3 , Fe 2 O 3 , CeO 2 , WO 2 , UO 2 , ThO 2 , TeO2, MoO 2 , and MoO 3 .
7 . The method of claim 1 , wherein the metal oxide comprises MgO.
8 . The method of claim 1 , wherein the first solvent comprises water and ethylene glycol.
9 . The method of claim 1 , wherein a) further comprises including a reducing agent in the mixture.
10 . The method of claim 1 , wherein a) further comprises including a surfactant to the mixture.
11 . The method of claim 1 , wherein the nickel precursor comprises NiCl 2 6H 2 O, the molybdenum precursor comprises (NH 4 ) 6 Mo 7 O 2 4H 2 O, and the metal oxide comprises MgO.
12 . The method of claim 1 , wherein a weight ratio of nickel from the nickel precursor to metal oxide in the mixture is 0.01 wt. % to 40 wt. %.
13 . The method of claim 1 , wherein a weight ratio of molybdenum from the molybdenum precursor to the metal oxide in the mixture is from 0.01 wt. % to 39.9 wt. %.
14 . The method of claim 1 , further comprising, after c), using the catalyst in a dry reforming reaction.
15 . The method of claim 14 , wherein the dry reforming reaction comprises reacting carbon dioxide and a C 1 -C 4 hydrocarbon to make carbon monoxide and hydrogen.
16 . The method of claim 14 , further comprising, after using the catalyst in a dry reforming reaction, removing coke from the catalyst.