METHOD FOR FORMING CATALYTIC NANOCOATING

Abstract

Provided is a method for forming catalytic nanocoating on a metal surface. The method comprises pretreating the metal surface by means of heat treatment at 500-800° C., forming a metaloxide support, and depositing catalytic nanosized metal and/or metaloxide particles on the metaloxide support and coating the metal surface with catalytic nanosized metal and/or metaloxide particles. Further, the invention relates to a catalyst and a use.

Claims

1. A method for forming a catalytic nanocoating on a metal surface, wherein the method comprises pretreating the metal surface by means of heat treatment at 500-800° C., forming a metaloxide support, and depositing catalytic nanosized metal and/or metaloxide particles on the metaloxide support and coating the metal surface with catalytic nanosized metal and/or metaloxide particles.

2. The method according to claim 1, wherein the metal surface is heat-treated by oxidizing.

3. The method according to claim 1, wherein the metaloxide support is formed by washcoating on the metal surface, and catalytic nanosized metal and/or metaloxide particles are deposited by means of flame spray pyrolysis (FSP) method on the metal surface which has been coated with the metaloxide support.

4. The method according to claim 3, wherein the metal surface is washcoated with a metaloxide based slurry.

5. The method according to claim 3, wherein the washcoating is carried out by spraying or dip-coating.

6. The method according to claim 3, wherein the metaloxide support formed by washcoating is calcined at 400-800° C.

7. The method according to claim 1, wherein nanoparticles of the metaloxide support are formed by means of a flame spray pyrolysis (FSP) method, catalytic nanosized metal and/or metaloxide particles are formed by means of chemical vapour synthesis (CVS) and deposited on the surface of the nanoparticles of the metaloxide support, and the metal surface is coated with catalytic nanosized metal and/or metaloxide particles.

8. The method according to claim 1, wherein the metaloxide support comprises Al.sub.2O.sub.3, MgO, TiO.sub.2, other metaloxide or their combination.

9. The method according to claim 1, wherein catalytic nanosized metal and/or metaloxide particles comprises metal selected from the group Co, Ni, Mo, Zr, Ti, Hf, noble metal, other suitable metal and their combinations.

10. The method according to claim 1, wherein a distance between the metal surface of the metal object and the flame is adjusted in connection with the flame spray pyrolysis (FSP).

11. A catalyst, wherein the catalyst comprises a catalytic nanocoating on the metal surface, and the catalytic nanocoating has been formed onto the metal surface by the method of claim 1.

12. A catalyst according to claim 11, wherein the catalyst is used in catalytic reactors, in self-cleaning surfaces, in production of biomass derived chemicals, in production of transportation fuels, in FT-synthesis, in reformers for fuel cell applications, in gas treatment units for syngas applications or in aqueous phase reformers for biorefineries.

13. A use of the method of claim 1, wherein the method is used to form a catalytic nanocoating in reactors, such as catalytic reactors reformers of fuel cell applications and aqueous phase reformers for biorefinery, and in processes, such as production of biomass derived chemicals, production of transportation fuels, FT-synthesis and gas treatment unit for syngas applications and production of self-cleaning surfaces, and their combinations.

Description

LIST OF DRAWINGS

[0029] In the following section, the invention will be described with the aid of detailed exemplary embodiments, referring to the accompanying drawings wherein

[0030] FIG. 1 presents a flowchart illustration of a method according to one embodiment of the present invention,

[0031] FIG. 2 presents a flowchart illustration of a method according to one embodiment of the present invention,

[0032] FIG. 3 presents one embodiment of the flame spray pyrolysis, and

[0033] FIG. 4 shows product concentration in outlet gas as function of residence time.

DETAILED DESCRIPTION OF THE INVENTION

[0034] FIGS. 1 and 2 present the method according to the invention for forming a catalytic nanocoating.

Example 1

[0035] In the method of FIG. 1 a catalytic nanocoating is formed on a metal surface.

[0036] The metal surface of the metal plate is pretreated (1) by means of heat treatment by oxidizing at 500-800° C. The metaloxide support, such as Al.sub.2O.sub.3 support, is formed (2) by washcoating (3) on the pretreated metal surface so that the metal surface is washcoated with metaloxide based slurry, such as Al.sub.2O.sub.3 based slurry, by spraying or dip-coating. The washcoated support is calcined (4) at about 400° C. on the metal surface. The catalytic nanosized metal and/or metaloxide particles, such as Co oxide particles, are deposited (5) by means of a flame spray pyrolysis (FSP) method on the metal surface which has been coated with the metaloxide support. The metaloxide nanoparticles are deposited above the flame on the metal oxide support.

[0037] The metal and/or metaloxide particles can be homogeneously dispersed on the metaloxide support, and at high temperature they are also well adhered on the surface.

Example 2

[0038] In the method of FIG. 2 a catalytic nanocoating is formed on a metal surface.

[0039] The metal surface of the metal plate is pretreated (1) by means of heat treatment at 500-800° C. Nanoparticles of the metaloxide support, such as nanoparticles of Al.sub.2O.sub.3 support, are formed (2,6) by means of a flame spray pyrolysis (FSP) method. Catalytic nanosized metal and/or metaloxide particles are formed (7) by means of chemical vapour synthesis (CVS) and deposited (8) on the surface of the nanoparticles of the metaloxide support. The metal surface is coated (9) with catalytic nanosized metal and/or metaloxide particles, which have been deposited on the nanoparticles of the metaloxide support. The catalytic nanosized metal and/or metaloxide particles which have been supported by the metaloxide support are deposited on the metal surface.

[0040] The devices used in examples 1 and 2 and this invention are known per se, and therefore they are not described in any more detail in this context.

Example 3

[0041] The metal surface of the metal plate was pretreated by means of heat treatment at 500-800 ° C.

[0042] The metaloxide (Al.sub.2O.sub.3) support was formed by washcoating on the pretreated metal surface so that the metal surface was washcoated with Al.sub.2O.sub.3 based slurry by spraying. The washcoated support was calcined, at about 400° C. on the metal surface. The catalytic nanosized. Co-oxide particles were deposited by means of a flame spray pyrolysis (FSP) method on the metal surface, which had been coated with the metaloxide support. The Co-oxide nanoparticles were deposited above the flame on the support. The Co-oxide particles were homogeneously dispensed on the metaloxide support, and at high temperature they were also well adhered on the surface.

[0043] The catalyst was tested for Fischer-Tropsch reaction in a laboratory scale reactor at 230° C. and atmospheric pressure. The feed gas contained 33.3 vol % CO and 66.7 vol % H.sub.2. The flow rate was varied from 0.15 to 1.00 l.sub.n/min. The measured product concentrations in outlet gas by gas chromatograph are depicted as function of residence time in FIG. 4. The catalyst produced methane and higher hydrocarbons. The activity of the catalyst increased steadily when the residence time was increased and there was no sign of the activity loss during the experiment.

[0044] The method according to the invention is suitable in different embodiments for forming different catalytic nanocoatings. The method according to the invention is suitable in different embodiments for forming different kinds of catalysts.

[0045] The invention is not limited merely to the examples referred to above; instead many variations are possible within the scope of the inventive idea defined by the claims.