Sulfur-Tolerant Catalyst Systems

Abstract

Methods for improving the sulfur-tolerance of nickel-based catalyst systems, as well as the improved catalyst systems, are disclosed. The methods can include adding praseodymium alone, or in combination with ruthenium and/or cerium, to a nickel-based catalyst system, thereby inhibiting sulfur poisoning of the catalyst system. Improved catalyst systems can have an added amount of praseodymium alone, or in combination with ruthenium and/or cerium, sufficient to inhibit poisoning of the system by sulfur.

1 . A catalyst system for processing a reactant comprising at least some sulfur, the catalyst system characterized by a mixed phase of Pr 3+  and Pr 4+  and a catalyst material, wherein the mixed phase of praseodymium inhibits sulfur poisoning of the catalyst material. 
     
     
         2 . The catalyst system of  claim 1 , further comprising ruthenium. 
     
     
         3 . The catalyst system of  claim 1 , further comprising cerium, 
     
     
         4 . The catalyst system of  claim 1 , further comprising ruthenium and cerium. 
     
     
         5 . The catalyst system of  claim 1 , wherein the catalyst material comprises nickel. 
     
     
         6 . The catalyst system of  claim 1 , wherein the catalyst material comprises Ni-YSZ. 
     
     
         7 . The catalyst system of  claim 1 , wherein the reactant is a fuel for a fuel cell and the catalyst system is contained in an electrode of the fuel cell, 
     
     
         8 . The catalyst system of  claim 1 , wherein the reactant is a hydrocarbon and the catalyst system is contained in a hydrocarbon reformation device. 
     
     
         9 . The catalyst system of  claim 8 , wherein the hydrocarbon reformation device is a hydrogen generator. 
     
     
         10 . A catalyst system for processing a reactant comprising at least some sulfur, the catalyst system characterized by praseodymium and a catalyst material comprising nickel, wherein the praseodymium inhibits sulfur poisoning of the catalyst material. 
     
     
         11 . The catalyst system of  claim 10 , wherein the catalyst material comprises Ni-YSZ. 
     
     
         12 . The catalyst system of  claim 10 , further comprising ruthenium. 
     
     
         13 . The catalyst system of  claim 10 , further comprising cerium. 
     
     
         14 . The catalyst system of  claim 10 , further comprising ruthenium and cerium. 
     
     
         15 . The catalyst system of  claim 10 , wherein the reactant is a fuel for a filet cell and the catalyst system is contained in an electrode of the fuel cell. 
     
     
         16 . The catalyst system of  claim 10 , wherein the reactant is a hydrocarbon and the catalyst system is contained in a hydrocarbon reformation device. 
     
     
         17 . The catalyst system of  claim 16 , wherein the hydrocarbon reformation device is a hydrogen generator. 
     
     
         18 . The catalyst system of  claim 10 , wherein the praseodymium comprises mixed valence states of Pr 3+  and Pr 4+ . 
     
     
         19 . A hydrogenerator comprising a catalyst system processing a sulfur-containing hydrocarbon, the catalyst system characterized by a mixed phase of Pr 3+  and Pr 4+  and a catalyst material, wherein the mixed phase of praseodymium inhibits sulfur poisoning of the catalyst material. 
     
     
         20 . A hydrogen generator comprising a catalyst system processing a sulfur-containing hydrocarbon, the catalyst system characterized by praseodymium and a catalyst material comprising nickel, wherein the praseodymium inhibits sulfur poisoning of the catalyst material.