Method for low temperature catalytic production of hydrogen

Abstract

The invention provides a process for the catalytic production of a hydrogen feed by exposing a hydrogen feed to a catalyst which promotes a base-catalyzed water-gas-shift reaction in a liquid phase. The hydrogen feed can be provided by any process known in the art of making hydrogen gas. It is preferably provided by a process that can produce a hydrogen feed for use in proton exchange membrane fuel cells. The step of exposing the hydrogen feed takes place preferably from about 80° C. to about 150° C.

1 . A process for catalytic production of a hydrogen feed which comprises: 
 providing a hydrogen feed; and    exposing said hydrogen feed to a catalyst which promotes a water-gas-shift reaction in a liquid phase.    
     
     
         2 . The process of  claim 1 , wherein said hydrogen feed is provided by steam reforming, oxidation of methanol, oxidation of methane, oxidation of biomass, coal gasification or gasification of organic wastes, plastics wastes farm wastes or wood chips  
     
     
         3 . The process of  claim 1  wherein said exposing step is conducted in a temperature range from about 80° C. to about 150° C.  
     
     
         4 . The process of  claim 1 , wherein formate is formed in a base-catalyzed water-gas-shift reaction.  
     
     
         5 . The process of  claim 4 , wherein said water-gas-shift reaction is conducted in the presence of a base added in an effective amount to promote formate formation.  
     
     
         6 . The process of  claim 5 , wherein said exposing step is conducted at a pH greater than 8.  
     
     
         7 . The process of  claim 5 , wherein said base is selected from hydroxides, alkoxides, carbonates, bicarbonates of lithium, sodium, potassium or cesium, amines having C 1  to C 4  or mixtures thereof.  
     
     
         8 . The process of  claim 1 , wherein said catalyst is a homogenous transition metal complex.  
     
     
         9 . The process of  claim 8 , wherein said transition metal is selected from the group consisting of Ru, Ni, Rh, Pt, Co, Cu, Pd, Ir and Fe.  
     
     
         10 . The process of  claim 8 , wherein said catalyst is a transition metal coupled to at least one N-donor ligand.  
     
     
         11 . The process of  claim 10 , wherein said N-donor ligand is selected from 2,2′-dipyridyl, sodium salt of ethylenediamine tetraacetic acid, ethylenediamine, 1,10-phenanthroline, 4,4′-dipyridyl, 1,4,8,11-tetraazacyclotetradecane, N,N-Bis(2-hydroxybenzyl)ethylenediamine H 4 , or mixtures thereof.  
     
     
         12 . The process of  claim 1 , wherein said liquid phase is water, methanol, glyme, polyglycol, other alcohols from C 2  to C 10  or ethers from C 2  to C 10 , and mixtures thereof.  
     
     
         13 . The process of  claim 1 , wherein said hydrogen feed has a CO concentration in an amount from about 50 ppm to less than about 20 ppm.  
     
     
         14 . A process for reducing CO content of a hydrogen feed for use in a proton exchange membrane fuel cell, said process comprising producing said hydrogen feed from formate in a liquid phase in the presence of a formate decomposition catalyst.  
     
     
         15 . The process of  claim 14 , wherein said process for producing hydrogen feed from formate is conducted in a temperate range from about 80° C. to about 150° C.  
     
     
         16 . The process of  claim 15 , wherein said formate is selected from formates of sodium, potassium, lithium and cesium.  
     
     
         17 . The process of  claim 14 , wherein said liquid phase is selected from water, methanol, glyme, polyglycol, other alcohols from C 2  to C 10  or ethers from C 2  to C 10 , and mixtures thereof.  
     
     
         18 . The process of  claim 14 , wherein said formate is generated from CO and hydroxide in a basic solution wherein the process is a water-gas-shift reaction.  
     
     
         19 . The process of  claim 18 , wherein said water-gas-shift reaction comprises the steps of: 
 (a) producing formate from CO and water; and    (b) decomposing formate in the presence of water to form said hydrogen feed and carbon dioxide.    
     
     
         20 . The process of  claim 14 , wherein said formate decomposition catalyst is a homogenous metal complex.  
     
     
         21 . The process of  claim 20 , wherein said homogenous metal complex is a transition metal complex having a metal selected from group VIII A.  
     
     
         22 . The process of  claim 21 , wherein said metal is selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt and Cu.  
     
     
         23 . The process of  claim 21 , wherein said transition metal complex is selected from the group consisting of RuCl 3 .xH 2 O, Ru 3 (CO) 12 , NiCl 2 .6H 2 O, RhCl 3 .3H 2 O, CoCl 2 , K 2 PtCl 4 , FeCl 2 , Ru(CO) 5 , Ni(CO) 4 , Rh 6 (CO) 16 , Co 2 (CO) 8 , [Pt(CO)(Cl 2 )] 2  and mixtures thereof.  
     
     
         24 . The process of  claim 23 , wherein said transition metal complex is in the presence of 2,2′-dipyridyl.  
     
     
         25 . The process of  claim 14 , wherein said hydrogen feed contains an amount of CO from about 50 ppm to less than about 20 ppm.  
     
     
         26 . A process for the production of a hydrogen rich gas from a gas stream including CO, H 2 O, H 2  and CH 3 OH which comprises oxidizing CO to CO 2  in the presence of a liquid-phase homogenous catalytic system.  
     
     
         27 . The process of  claim 24 , wherein said homogenous catalytic system is a metal complex coupled to at least one N-donor ligand.  
     
     
         28 . A process for catalytic production of a hydrogen feed which comprises: 
 providing a hydrogen feed; and    exposing said hydrogen feed to a homogenous catalyst which promotes a water-gas-shift reaction in a liquid phase at a temperature from about 80° C. to about 150° C.