Oxygen carrying materials with surface modification for redox-based catalysis and methods of making and uses thereof

Abstract

Redox catalysts having surface medication, methods of making redox catalysts with surface modification, and uses of the surface modified redox catalysts are provided. In some aspects, the redox catalysts include a core oxygen carrier region and an outer shell having an average thickness of about 1-100 monolayers surrounding the outer surface of the core region.

1 . An redox catalyst comprising:
 (a) a core region comprising an outer surface and an inner surface, the core region comprising an oxygen carrier,   
       wherein:
 an outer shell having an average thickness of about 1 to 100 monolayers and comprising a metal salt surrounds the outer surface of the core region, and 
 the core region contributes at least 50% of the oxygen required in an oxidative dehydrogenation reaction in which the redox catalyst is present. 
 
     
     
         2 . The redox catalyst according to  claim 1 , wherein the oxygen carrier comprises an oxide having a cubic crystal lattice structure, wherein the oxide is selected from the group consisting of Mg 6 MnO 8 , Cu 6 PbO 8  and Ni 6 MnO 8 . 
     
     
         3 . The redox catalyst according to  claim 2 , wherein the oxide is Mg 6 MnO 8 . 
     
     
         4 . The redox catalyst according to  claim 1 , further comprising an alkali metal or an alkali metal-containing compound. 
     
     
         5 . The redox catalyst according to  claim 1 , further comprising boron or a boron-containing compound. 
     
     
         6 . The redox catalyst according to  claim 2 , wherein the oxide comprises an alkaline earth metal. 
     
     
         7 . The redox catalyst according to  claim 2 , wherein the oxide comprises manganese, wherein the manganese has a valence state selected from 4 + , 3 + , 8/3 + , and 2 + . 
     
     
         8 . The redox catalyst according to  claim 1 , wherein the oxygen carrier comprises:
 an oxide comprising at least one of NaB 2 Mg 4 Mn 2 O 4 , NaB 2 Mn 2 Mg 4 O 11.5 , NaMn 2 O 4 , LiMn 2 O 4 , Mg 3 Mn 3 B 2 O 10 , Mg 3 (BO 3 ) 2 ;   a non-crystalline compound comprising oxygen; and   at least one of sodium, boron, magnesium, manganese, and lithium.   
     
     
         9 . The redox catalyst according to  claim 1 , wherein the oxygen carrier comprises:
 an oxide comprising at least one of NaB 2 Mg 4 Mn 2 O 4 , NaB 2 Mn 2 Mg 4 O 11.5 , NaMn 2 O 4 , LiMn 2 O 4 , Mg 3 Mn 3 B 2 O 10 , Mg 3 (BO 3 ) 2 ;   a non-crystalline compound comprising oxygen; and   at least one of sodium, boron, magnesium, manganese, and lithium.   
     
     
         10 . The redox catalyst according to  claim 1 , further comprising at least one of Na, Li, W and P as a promoter. 
     
     
         11 . A system for the oxidative dehydrogenation of unsaturated hydrocarbons comprising:
 a reactor defining an inner volume at least partially filled with the redox catalyst according to  claim 1 ;   an inlet stream attached to the reactor, the inlet stream configured to deliver at least one of a saturated hydrocarbon and an oxygen-containing gas to the reactor; and   an effluent stream attached to the reactor, the effluent stream configured to allow the removal of at least one of unsaturated hydrocarbons, water, and an oxygen-depleted gas from the reactor,   wherein the reactor is configured to enable the contact of the redox catalyst with at least one of the saturated hydrocarbons and the oxygen-containing gas.   
     
     
         12 . The system according to  claim 11 , further comprising a source of unsaturated hydrocarbon attached to the inlet stream. 
     
     
         13 . The system according to  claim 11 , further comprising a source of oxygen-containing gas attached to the inlet stream. 
     
     
         14 . The system according to  claim 13 , wherein the oxygen-containing gas is air. 
     
     
         15 . The system according to  claim 11 , wherein the reactor further comprises a hydrocarbon reaction section configured to circulate the redox catalyst within the inner volume of the reactor. 
     
     
         16 . A process for the production of an unsaturated hydrocarbon comprising:
 providing a saturated hydrocarbon to a reactor at least partially filled with the redox catalyst according to  claim 1 ;   contacting the saturated hydrocarbon with the redox catalyst to convert the saturated hydrocarbon into the unsaturated hydrocarbon;   removing an effluent from the reactor containing the unsaturated hydrocarbon; and   supplying oxygen to the redox catalyst such that the redox catalyst is oxidized.   
     
     
         17 . The process of  claim 16 , wherein the supplying of the oxygen is performed intermittently between periods of providing the saturated hydrocarbon. 
     
     
         18 . The process of  claim 16  further comprising separating the unsaturated hydrocarbon from the effluent. 
     
     
         19 . The process of  claim 16  wherein the saturated hydrocarbon is at least one of ethane and propane. 
     
     
         20 . The process of  claim 16  wherein the unsaturated hydrocarbon is at least one of ethylene and propylene. 
     
     
         21 . The process of  claim 16 , wherein the redox catalyst comprises a shell of at least one of Na, W and P.