Platinum Based Catalyst for Oxidation/Reduction Reaction and Its Use
Disclosed herein are a platinum-based catalyst for oxidation/reduction reactions and the use thereof. The platinum-based catalyst is prepared by loading a catalyst composition comprising a water-soluble salt of at least one metal selected from among cerium (Ce), zirconium (Zr) and rhenium (Re), on a support comprising at least one selected from among alumina, silica and titania. The disclosed catalyst can be prepared in a simple manner without any particular limitation as to the kind of usable water-soluble platinum salt, and when it is applied to various oxidation reactions, including water gas shift reactions of carbon monoxide, three-way catalytic reactions, and selective oxidation reactions of carbon monoxide, and to reduction reactions, such as reactions of removing nitrogen oxide (NOx), it will show excellent catalytic activity. In particular, the disclosed catalyst shows excellent performance even in a specific temperature range in which it is difficult to apply the prior high-temperature water gas shift reaction catalyst and low-temperature water gas shift reaction catalyst. Also, it can remove carbon monoxide even at high temperatures without the loss of hydrogen caused by methanation, and thus is particularly useful in a hydrogen production process of producing high-purity hydrogen for fuel cells.
1 . A platinum-based catalyst for oxidation/reduction reactions, which is prepared by impregnating a catalyst composition comprising (i) a water-soluble salt of at least one metal selected from among cerium (Ce), zirconium (Zr) and rhenium (Re), (ii) a water-soluble platinum salt, (iii) a C2-C10 alkylene oxide and (iv) water, on a support comprising at least one selected from alumina, silica and titania, and drying and calcining the impregnated catalyst composition.
2 . The platinum-based catalyst of claim 1 , wherein the water-soluble salt of the metal may be cerium nitrate.
3 . The platinum-based catalyst of claim 1 , wherein the water-soluble platinum salt is a compound which contains or does not contain a halogen atom.
4 . The platinum-based catalyst of claim 1 , wherein the water-soluble platinum salt is chloroplatinic acid (H 2 PtCl 6 ).
5 . The platinum-based catalyst of claim 1 , wherein the alkylene oxide may be propylene oxide or butylene oxide.
6 . The platinum-based catalyst of claim 1 , wherein the catalyst composition comprises the alkylene oxide in an amount corresponding to 0.5-10 times a sum of values obtained by multiplying the number of moles of each cationic species present in the catalyst composition by the oxidation number of the cationic species.
7 . The platinum-based catalyst of claim 1 , wherein the platinum-based catalyst comprises 1-20 wt % of the metal 0.1-10 wt % of platinum and 70-98 wt % of the support.
8 . The platinum-based catalyst of claim 1 , wherein the support for the catalyst is (i) powder, (ii) a sphere, (iii) a extrudate in the form of a granule, or (iv) a pelletized material.
9 . The platinum-based catalyst of claim 1 , wherein the support for the catalyst can be coated on a monolith substrate selected from a group consisting of a metal foam, a ceramic foam and a honeycomb, a metal plate or a metal fabric.
10 . The platinum-based catalyst of claim 1 , wherein the catalyst is prepared by grinding the catalyst, making a slurry using the ground catalyst, and coating the slurry on a monolith substrate selected from a group consisting of a metal foam, a ceramic foam and a honeycomb, a metal plate or a metal fabric.
11 . A method of using a platinum-based catalyst according to claim 1 in an oxidation or reduction reaction selected from the group consisting of a water gas shift reaction of carbon monoxide, a three-way catalytic reaction, a selective oxidation reaction of carbon monoxide and a reaction for removing nitric oxides.