Device and method for loading catalyst supports with nanoparticulate catalyst precursors from the gas phase

Abstract

The present invention relates to a device and a method for loading catalyst supports by depositing a nanoparticulate catalyst precursor from a carrier gas onto the surface of the catalyst support, wherein the device comprises a housing, a transport shaft having circulating devices arranged on the transport shaft, and a supply unit for carrier gas.

Description

[0001] Device and method for loading catalyst supports with nanoparticulate catalyst precursors from the gas phase

[0002] The present invention relates to a device and a method for loading catalyst supports by depositing a nanoparticulate catalyst precursor from a carrier gas onto the surface of the catalyst supports, wherein the device comprises a housing, a transport shaft with circulation devices arranged on the transport shaft and a supply of carrier gas.

[0003] The efficient loading of solid catalyst support surfaces with the effective solid or liquid catalyst substances is not trivial in technical implementation. This is especially true in cases where a solid support material consisting of more or less uniformly shaped, relatively small support particles is to be coated with catalyst substances from a carrier gas stream. Here, the different phases—solid catalyst support surface and gaseous carrier stream—pose particular challenges. For the economical production of the supported catalysts, both rapid and controllable loading is important. Reproducible activities of the final catalyst support are achieved through uniform and sufficient loading of catalyst substances.Under the constraints of rapid production, one can attempt to achieve this by high loading of the carrier gas stream with catalyst substances. Disadvantageously, a high loading of the carrier gas stream can lead to uneven loading of the overall support surfaces and to unwanted losses due to undeposited catalyst substances in the carrier gas stream. Both factors lead to a significant increase in the cost of the catalysts.

[0004] The patent literature also contains a wide variety of approaches to loading catalyst surfaces.

[0005] For example, EP0453674B1 describes a process for the preparation of catalysts in which a catalytically effective amount of cobalt is distributed as a layer on the peripheral outer surface of a particulate, porous inorganic oxide support to form a catalyst useful for the conversion of synthesis gas to hydrocarbons, and the support particles are contacted with a spray containing a decomposable compound of the metal or metals, the process comprising maintaining a bed of the support particles in a fluidised state at a temperature in the range of about 50°C to about 100°C by contact with a gas at a temperature in the range of about 50°C to about 100°C;spraying the bed of heated support particles with a liquid having dispersed therein a compound or compounds of cobalt at a flow rate effective to provide a ratio of liquid flow rate to fluidizing gas flow rate of less than about 0.6 g liquid / foot; 3 (0.6 g / 28.32 l) of fluidizing gas is sufficient to form a surface layer of the metal on the particles with an average thickness in the range of about 20 microns (20 pm) to about 250 microns (250 pm), the loading of the metal calculated as metallic metal per packed bulk volume of the catalyst being in the range of about 0.01 g / cm 3 up to about 0.15 g / cm 3 lies.

[0006] EP2045011B1 describes a method for producing an exhaust gas purification catalyst. The method comprises: (a) providing a colloidal solution containing a colloidal particle of rare earth hydroxide or oxide, (b) adding a zirconia-based metal oxide particle to the colloidal solution to cause the colloidal particle to be adsorbed and loaded onto the surface of the zirconia-based metal oxide particle, (c) drying and firing the zirconia-based metal oxide particle with the colloidal particle adsorbed and charged thereon to obtain a catalyst support particle, and (d) loading rhodium onto the catalyst support particle.

[0007] Such solutions known from the prior art may offer further potential for improvement. This particularly relates to the provision of a device with which catalyst support particle surfaces can be loaded very uniformly and efficiently from a gas stream within a single process step.

[0008] It is therefore the object of the present invention to at least partially overcome the disadvantages known from the prior art. In particular, the object of the present invention is to provide a device that enables the uniform and rapid loading of surfaces with nanoparticulate, catalytically active substances from a gas stream.

[0009] The object is achieved by the features of the independent claims, directed to the device according to the invention, the method according to the invention, and the use of the device according to the invention. Preferred embodiments of the invention are specified in the subclaims, in the description, or in the figures. Further features described or shown in the subclaims, in the description, or in the figures may constitute an object of the invention, individually or in any combination, unless the context clearly indicates otherwise.

[0010] According to the invention, there is accordingly provided a device for loading catalyst supports by depositing a nanoparticulate catalyst precursor from a carrier gas onto a surface of the catalyst supports, the device comprising at least: a) a housing, the housing extending from a housing base to a housing cover at a height H and perpendicular thereto with a width B, wherein a ratio of the height and width of the housing, calculated as the height of the housing divided by the width of the housing, is greater than or equal to 1 and less than or equal to 20; b) a rotatable transport shaft arranged inside and on a central axis of the housing with one or more circulation devices arranged on the transport shaft, the circulation devices being designed to transport the catalyst support both axially and radially within the housing;and c) a supply for the carrier gas containing the nanoparticulate catalyst precursor arranged in a lower region of the housing, wherein the lower region of the housing extends from the housing bottom to less than or equal to 30% of the height of the housing into the housing;

[0011] Surprisingly, it was discovered that a multitude of catalyst supports of different sizes and shapes can be coated very quickly and uniformly with nanoparticulate catalyst precursors using the device described above. This results in highly efficient catalysts with a uniform activity profile. The utilization of the nanoparticulate catalyst precursors contained in a carrier gas is very complete, so that the residual loading of the carrier gas with nanoparticulate catalyst precursors after absorption is extremely low or even eliminated entirely. Furthermore, the loading of the carrier gas can, in principle, also be increased compared to the prior art processes. Thus, complete and homogeneous loadings can be achieved even with small amounts of carrier gas.These advantages are achieved in particular by moving the still unloaded catalyst supports in the device and by specifically supplying the loaded carrier gas. The loading device has particular advantages over the standard depth filtration. Depth filtration is a common method for separating solid particles, liquid droplets or gaseous molecules from mobile phases, such as aqueous or gaseous stationary phases, onto an aqueous or solid phase. The principle is used, for example, in respiratory protection equipment, gas treatment plants or activated carbon filters. For this purpose, a powdered or pelletized material with a large surface area is usually flowed through in a stationary manner by the gas stream to be freed, whereby the droplets, gas molecules or particles are separated on the large surface.The disadvantage of this approach to nanoparticle separation is that only very small amounts of particles are separated, while a large number remain in the gas stream. Furthermore, the particles cannot be separated on any material or shaped body. Depth filtration is not suitable for the stationary separation of nanoparticles if they are to be used to produce catalyst precursors or catalysts. Stationary separation leads to uneven separation, with an enrichment of separated particles at the beginning of the medium and a strong concentration gradient with low loadings towards the end of the medium. However, for the production of improved catalyst precursors or catalysts, a uniform particle concentration throughout the material is desirable.

[0012] The device according to the invention is a device for loading catalyst supports. Catalyst supports are solid particles which, as such, are generally not catalytically active themselves. The catalyst supports provide the mechanically stable framework and the surface on which the catalytically active substances are deposited. In the device according to the invention, the unloaded catalyst support is equipped to form an active catalyst. This is achieved by the deposition of the catalyst substances on the surface and, if appropriate, partially in an inner region of the catalyst support. The catalyst supports can have a regular shape, for example, a round, ellipsoidal, or cylindrical shape. However, it is also possible for the catalyst supports to be irregularly shaped. The particles of the catalyst support can have a single size or a size distribution.Preferably, catalyst supports with a size or average size in the range of 1 μm to 10 cm can be used. More preferably, the size of the catalyst supports can be from 1 μm to 1 cm. Suitable catalyst supports include, for example, carbon powders with a large specific area (activated carbon in powder form or pellets), oxidic inorganic materials such as Al2O3 in its various modifications (alpha, beta, gamma Al2O3), silicon dioxide, cerium oxide, titanium dioxide, and mixed oxides such as steatite, bentonite, and montmorillonite.

[0013] The catalyst is obtained by depositing a nanoparticulate catalyst precursor from a carrier gas. The finished catalyst is obtained from the catalyst support by deposition of catalytically active substances from a gas phase. The catalytically active substances are added to the catalyst support in nanoparticulate form, suspended or dispersed in a gas phase. In this context, nanoparticulate means that the individual particles of the catalyst precursor, whether solid or liquid, have an average size of less than or equal to 1 pm. For example, these can be liquid droplets or solid particles, which have an average size of 50 nm in the gas stream. The size of the catalyst precursor in the carrier gas can be determined, for example, by light scattering.The catalyst precursor usually exhibits a specific catalytic effect, which is tailored to its subsequent function within a chemical reaction. Due to the possibility of use in a wide variety of reactions, very different substances can be used as catalyst precursors. Possible nanoparticulate catalyst precursors include metals such as nickel, platinum, copper, iridium, palladium, iron, cerium, and many more, or semiconducting materials such as silicon, germanium, indium tin oxide (ITO), and many more. The nanoparticles can be produced by spark discharge ablation and are characterized by the absence of ligands. The catalyst precursors can also be dispersed in a liquid phase. Possible examples include soluble complex compounds of the above-mentioned metals, such as hexachloroplatinic acid or its salts, nickel nitrate and its hydrates, and chlorine-, sulfate-, and nitrate-containing compounds of the metals.The ratio between nanoparticulate catalyst precursor and carrier gas can be variably determined. For example, one liter of carrier gas can be loaded with 5 mg of nanoparticulate catalyst precursor under standard conditions. Loadings in the range of greater than or equal to 0.001 mg and less than or equal to 1000 mg are possible. High loadings of carrier gas can preferably be processed using the devices according to the invention. Inert gases such as nitrogen, noble gases, or even carbon dioxide can be used as carrier gases, for example.

[0014] The nanoparticulate catalyst precursor is deposited onto the surface of the catalyst support. The solid or liquid catalyst precursor is passed through the bed of catalyst supports and comes into contact with them. Contact occurs on the surface of the catalyst support, with some or all of the catalyst precursor remaining on the surface. It is also possible for the catalyst precursor to partially or completely diffuse into the catalyst support. This can be particularly the case when a liquid catalyst precursor is used, which is applied to a porous catalyst support.

[0015] The device according to the invention comprises a) a housing, the housing extending from a housing base to a housing cover at a height H and perpendicular thereto with a width B, wherein a ratio of the height and width of the housing, calculated as the height of the housing divided by the width of the housing, is greater than or equal to 1 and less than or equal to 20. The housing of the device delimits the actual loading location of the catalyst support from the environment. The height H is the internal height of the container, i.e. the part which could also be filled with catalyst support. Likewise, the width is the distance between the internal walls of the container. According to the invention, the height is in a specific ratio to the width, wherein the ratio indicates that the container is higher than it is wider.The ratio can more preferably be greater than or equal to 2 and less than or equal to 17, and more preferably greater than or equal to 5 and less than or equal to 15. Within these limits, the loading efficiency can be increased compared to shorter interior spaces. In particular, the axial direction of movement of the catalyst supports appears to be more important for coating uniformity.

[0016] The device according to the invention comprises b) a rotatable transport shaft arranged inside and on a central axis of the housing, with one or more circulation devices arranged on the transport shaft, wherein the circulation devices are designed to transport the catalyst support both axially and radially within the housing. In the case of symmetrically designed interior spaces, the central axis of the housing results as the axis of symmetry of the housing. In the case of a cylindrically designed interior space, the central axis runs through the axis of symmetry of the cylinder, i.e. through the center of the circle's base area. A transport shaft runs on or along this central axis. The transport shaft is not rigid, but can rotate in one or two directions. For example, the basic shape of the shaft can be round. This would result in a rod-shaped transport shaft.The circulation devices are mounted at different heights on the shaft. One, two, three, or more circulation devices can be mounted on the shaft. The circulation devices have a geometry capable of moving a bulk material moved by these devices both radially in a plane and axially along the transport shaft. The transport of the catalyst support during loading includes both a translational and a rotational movement component. For this purpose, the circulation devices can be designed to be flat, for example, blade-shaped. Examples of possible circulation device designs are shown in the figures. One or more circulation devices can be mounted at a specific height on the shaft.

[0017] The device according to the invention comprises c) a supply line for the carrier gas containing the nanoparticulate catalyst precursor, arranged in a lower region of the housing, wherein the lower region of the housing extends from the housing base into the housing to less than or equal to 30% of the height of the housing. The loaded carrier gas is supplied in the region of the housing base and not in the region of the housing cover. The supply line can consist of lines or tubes that penetrate the container wall and form separate internals from the housing. It is also possible for the loaded carrier gas to enter the interior of the container via the shaft. Alternatively, the supply line can also be provided via additional structures such as baffles. The decisive factor is that the supply line takes place in the lower region of the housing. The carrier gas can be introduced into the housing, for example, by blowing it into the housing at increased pressure.The carrier gas can enter the housing and thus the bed of catalyst supports at one or more locations. Preferably, the feed can take place in a lower region of the housing, which extends from the housing base to less than or equal to 25%, more preferably to less than or equal to 15%, of the height H of the housing into the housing.

[0018] In a preferred embodiment of the device, the rotatable transport shaft can be configured with one or more circulation devices arranged on the transport shaft in the form of a conveyor screw, wherein the diameter of the circulation devices of the conveyor screw, relative to the inner diameter of the housing at the respective height position, calculated based on the maximum height-related diameter of the circulation device divided by the height-related inner diameter of the housing, is greater than or equal to 0.60 and less than or equal to 0.98. To achieve particularly efficient loading of the catalyst supports, it has proven advantageous for the circulation devices to be adapted relative to the inner diameter present in their mounting position.Since the vessel can have different inner diameters at different heights, this ratio depends on the relative height of the relevant circulation device within the vessel. If the circulation device has a variable diameter, the largest diameter of the circulation device is used for the calculation. Within these dimensions, both the carrier gas and the catalyst support can move within the vessel with the correct proportions of radial and axial movement components. The passage of the carrier gas also appears to be homogeneous within this ratio. Smaller ratios can be disadvantageous because in this case, mixing of the edge regions is no longer sufficiently ensured. Higher ratios can be disadvantageous because in these cases the axial movement direction of the catalyst support becomes too small.Further preferably, the ratio can be greater than or equal to 0.75 and less than or equal to 0.93, and more preferably greater than or equal to 0.82 and less than or equal to 0.90. To prevent deposits on the vessel wall, the shaft can preferably be shaped such that it performs an eccentric movement. The latter can reliably prevent any deposits from building up on the housing wall.

[0019] In a preferred embodiment of the device, one or more baffles can be arranged between an inner wall of the housing and the transport shaft. The installation of baffles has proven particularly suitable for improved mixing of the catalyst supports and better contact between the catalyst supports and the carrier gas. The baffles can, for example, be in the form of metal sheets or projections on and along the inner wall of the housing. However, it is also possible for the baffles not to be attached to the inner wall. In this case, the baffles can be attached to the housing cover, for example, and the baffles can protrude into the interior of the housing. The baffles can be in the shape of a cylinder or a sleeve arranged concentrically around the shaft.In the height ranges not occupied by circulation devices, the baffles can modify and direct the convection of the bed forced by the circulation devices. Overall, a more uniform deposition of the catalyst precursor on the surface of the supports can be achieved. Preferably, more than two, further preferably more than three spaced-apart baffles can be present in the vessel. Preferably, the width of the baffles perpendicular to the horizontal direction of rotation of the shaft can be at least twice an average particle diameter of the third quartile of the particle diameter distribution. Preferably, the baffles extend vertically to 50 to 80% of the internal height of the vessel.If flow breakers are installed in the form of a sleeve, this can be formed, for example, from sheet metal, which has a distance from the shaft equal to an average particle diameter of the second quartile of the particle size distribution. The distance of the sleeve from the outer wall can, for example, be at least three times the length of a particle diameter of the 90th percentile of the particle size distribution. These configurations are particularly suitable for loading round or spherical catalyst supports, which exhibit a low tendency to agglomerate.

[0020] In a preferred embodiment of the device, the carrier gas containing the nanoparticulate catalyst precursor can be supplied via one or more nozzles, with a maximum nozzle opening of greater than or equal to 10% and less than or equal to 85% based on the average particle size of the support material. For uniform loading of the catalyst supports and to prevent blockages in the carrier gas supply, the above-specified range of possible nozzle openings as a function of the average particle size to be coated has proven particularly suitable. Otherwise, particularly with moving beds, blockages in the nozzle or an uneven carrier gas supply may occur during operation, resulting in a non-reproducible, uneven coating of the bed and / or individual particle surfaces.Smaller nozzle diameters can be disadvantageous because they result in excessive flow resistance for the carrier gas. Larger diameters can contribute to the proportion of particles entering the nozzle opening becoming too large. The maximum nozzle opening of the nozzle can preferably be greater than or equal to 20% and less than or equal to 80%, more preferably greater than or equal to 30% and less than or equal to 70%, based on the average particle size of the carrier material. The nozzle opening is the part of the nozzle which opens directly into the container as an outlet. The nozzle can preferably be an annular slot nozzle. In a preferred embodiment of the device, the nozzles can be arranged on the inner wall of the housing, with an angular orientation of a nozzle outlet being greater than or equal to 10° and less than or equal to 60° based on a vector running axially towards the housing base at this point within the inner wall.In addition to the maximum size of the nozzle opening, the correct orientation of the nozzle outlet can also contribute to an improvement in the loading result. To ensure even loading, a downward orientation of the nozzle outlet, i.e. towards the vessel bottom, has proven particularly suitable. The nozzle outlets are therefore inclined by the specified angular range from the vessel wall towards the vessel center or towards the shaft. Smaller angle ranges can lead to improperly mixed dead spaces, whereas larger angles can contribute to the carrier gas passing through the bed too quickly. The angular range can preferably be greater than or equal to 20° and less than or equal to 50°, further preferably greater than or equal to 25° and less than or equal to 45°.

[0021] In a further preferred embodiment of the device, the carrier gas containing the nanoparticulate catalyst precursor can be supplied via the rotatable transport shaft. For a uniform supply of the carrier gas into the catalyst support bed, supply via the shaft has proven particularly suitable. Due to the radial symmetry of the supply, a homogeneous distribution of the carrier gas in the container results. The nozzles can be designed, for example, in the form of holes or nozzle outlets, wherein the maximum nozzle diameters and the outlet direction can correspond to the ranges specified above. In this embodiment, more than 2, more than 5, and more preferably more than 10 nozzle outlets can be present on the shaft.

[0022] In a further preferred embodiment of the device, the housing can be conical in design, at least in sections. For uniform movement of the catalyst carrier in the housing, it has proven advantageous if not the entire interior space has a uniform inner diameter. At least part of the interior space therefore has a non-constant inner diameter, whereby this part can preferably be present at the housing bottom. This region of the interior space can, for example, be designed in the shape of a truncated cone. This region can preferably extend over at least 5%, preferably 10% of the total height of the interior space H. This region can preferably not have any circulation devices. The gradient of this region can preferably be greater than or equal to 40° and less than or equal to 45°.Within these areas, for example, dead spaces at the bottom of the tank can be avoided or a zone with a modified flow or movement profile can be created.

[0023] In a preferred embodiment of the device, the device can also comprise an outlet arranged in an upper region of the housing for the catalyst support, at least partially superficially loaded with a nanoparticulate catalyst precursor, and the carrier gas depleted of the nanoparticulate catalyst precursor, wherein the upper region of the housing extends from the lower edge of the housing cover into the housing to less than or equal to 30% of the height of the housing. Particularly for continuous production, it has proven suitable for the upper part of the housing to have an outlet through which the loaded particles are guided out of the housing. The depleted carrier gas can also escape or be removed in a directed manner through the outlet. This embodiment can be carried out with or without a continuous supply of carrier particles.If this is done with a continuous supply of catalyst supports, an overall continuous process can be established.

[0024] In a preferred characteristic of the device, a compaction unit can be arranged before the discharge of the catalyst-loaded catalyst support, wherein the compaction unit is designed to compact the catalyst-loaded catalyst support into agglomerates. In addition to simply discharging the loaded particles, they can also be conditioned within the housing. In addition to drying, this can be achieved, as described above, by producing different particle sizes. Mechanical compaction can improve the handling of the catalysts and, for example, prevent dust formation in the finished catalysts. Compaction can be achieved by mechanical pressing using mechanical press rams or by a compaction screw, both of which increase the density of the loaded catalysts.

[0025] Furthermore, the invention relates to a process for producing supported catalysts, wherein a catalyst support is contacted with a nanoparticulate catalyst precursor in a carrier gas in a device according to the invention. The device according to the invention is particularly suitable for use in processes in which supported catalysts are to be produced. This results in the process advantages already discussed in the field of the device according to the invention. In summary, the process allows for the rapid, simple, and reproducible production of loaded catalyst supports.

[0026] In a preferred embodiment of the process, the loading of the nanoparticulate catalyst precursor in the carrier gas can be greater than or equal to 10 mg / L and less than or equal to 500 mg / L. Within this range, large amounts of catalyst support can be loaded quickly and reproducibly. This loading of the carrier gas is not achievable with conventional methods, since in these cases only an inhomogeneous loading of the particles occurs.

[0027] In a preferred embodiment of the process, the process can be carried out with a volume-related loading of the device with catalyst support of greater than or equal to 50% and less than or equal to 95%. Within this range, large quantities of catalyst support can be loaded quickly and reproducibly. This loading level is not achievable with conventional processes, since in these cases only an inhomogeneous loading of the particles is achievable.

[0028] Furthermore, the invention provides for the use of a device according to the invention for loading catalyst supports with an average particle size determined by laser light scattering of greater than or equal to 0.1 pm and less than or equal to 250 pm. The device according to the invention is particularly suitable for use in processes in which supported catalysts are to be produced. The advantages of use are those already discussed in the section on process advantages and device advantages. In summary, loaded catalyst supports can be produced quickly, easily, and reproducibly using the device according to the invention.

[0029] Within a further preferred aspect of the use, the catalyst supports can have an average particle size, determined by laser light scattering, of greater than or equal to 250 pm and less than or equal to 1 cm. This size class of catalyst supports, in particular, can be coated very homogeneously and reproducibly using the method according to the invention with the device according to the invention.

[0030] Further advantages and advantageous embodiments of the inventive objects are illustrated by the figures and explained in the following examples. It should be noted that the figures are for descriptive purposes only and are not intended to limit the invention in any way.

[0031] The

[0032] Fig. 1 is a schematic representation of a device according to the invention in section;

[0033] Fig. 2 is a schematic representation of a rotatable transport shaft with circulation devices arranged thereon, in section; Fig. 3 is a further schematic representation of a device according to the invention, in plan view;

[0034] Fig. 4 shows a further schematic representation of a device according to the invention in section with integrated flow breaker;

[0035] Fig. 5 is a schematic representation of a baffle in plan view;

[0036] Fig. 6 shows a further schematic representation of a device according to the invention with flow breaker and annular slot nozzle;

[0037] Fig. 7 is a schematic representation of an annular slot nozzle for a device according to the invention.

[0038] Figure 1 shows a schematic cross-sectional view of a device according to the invention. The device consists of a housing 1, which defines the loading space through its inner walls. The housing 1 extends from the housing base 2 to the housing cover 3. The housing cover 3 seals the interior of the housing 1 from the environment. In this case, the housing 1 has approximately the shape of a hollow cylinder. The entire distance from the housing base 2 to the housing cover 3 forms the height H. The widest inner diameter of the housing 1 forms the width B. The housing 1 is advantageously higher than it is wider. A transport shaft 4 is arranged inside the housing 1 on the central axis of symmetry of the cylinder. The transport shaft 4 can, for example, be driven from outside the housing 1. In the illustrated case, the transport shaft 4 is driven from above. The transport shaft 4 contacts the housing base 2 at its lower end.A plurality of circulation devices 5 are arranged on the rotatable transport shaft 4, wherein the circulation devices 5 are designed to continuously or intermittently circulate a bed of catalyst supports located inside the housing 1. The circulation takes place both in the axial and radial directions with respect to the housing 1. This ensures uniform loading of the surface of the individual catalyst supports. The bed inside the housing 1 is loaded by the introduction of a nanoparticulate catalyst precursor, which can be liquid or solid under the loading conditions. The nanoparticulate catalyst precursors enter the housing 1 via the feed 6. The feed 6 is angled and directed downwards so that the carrier gas flows through the lower regions of the housing 1 and so that the feed 6 is not blocked over time by loaded or unloaded catalyst supports.The carrier gas flows through the stirred bed, and the nanoparticulate catalyst precursors are absorbed on the surface of the catalyst supports. The carrier gas flows through the entire stirred bed and exits the housing 1 through outlet 7 as a gas stream depleted of catalyst precursors. In batch operation, the catalyst support remains in the housing 1 until fully loaded. In continuous operation, the catalyst support can enter the interior of the housing through another, independent feed (not shown) and exit the housing via outlet 7 or an independent outlet (not shown).

[0039] Figure 2 shows a schematic cross-sectional view of a rotatable transport shaft 4 with circulating devices 5 arranged thereon. The transport shaft 4 with circulating devices 5 arranged thereon is designed in the form of an upright conveyor screw 11. The transport shaft 4 can be seated on the container base 2. The diameter of the circulating devices 5 is matched to the inner diameter of the housing 1, resulting in a defined gap to the inner wall of the housing 1 as a function of the average particle size to be coated. The rotatable transport shaft 4 can be rotatable in one or two directions. Furthermore, the shaft can be moved continuously or discontinuously.

[0040] Figure 3 shows a further schematic representation of a device according to the invention in plan view. The rotatable transport shaft 4 is moved by a motor (not shown) mounted outside the housing 1. The carrier gas loaded with the nanoparticulate catalyst precursor is fed into the housing 1 through the inlet 6. In this case, no separate discharge for the carrier gas from the housing 1 is provided. Figure 4 shows a further schematic representation of a device according to the invention in section with an integrated baffle 9. This figure shows the same functional features as in Figure 1. The housing 1 has a housing base 2 and a housing cover 3. The inlet 6 supplies the carrier gas with nanoparticulate catalyst precursor.The catalyst carrier is moved within the housing 1 by a rotatable transport shaft 4 with one or more circulation devices 5 arranged on the transport shaft 4. Additionally, this figure shows a flow breaker 9, which projects into the loading space and changes the direction of movement of the catalyst carriers. In this embodiment, the flow breaker 9 is in the form of a sleeve and arranged on the housing 1. The sleeve encloses the transport shaft 4 and is located at a height position where no circulation devices 5 are present. Alternatively, the flow breaker 9 can also be attached to the inner walls of the housing 1.

[0041] Figure 5 shows a schematic representation of a flow breaker 9 in plan view. This flow breaker 9 can be arranged on the cover of the housing and protrudes into the housing interior in the form of a sleeve. In addition to the sleeve itself, other functional components can be arranged on the sleeve. In this case, the surface of the sleeve also has projections 12, which can contribute to the directed movement of the catalyst carrier or the carrier gas.

[0042] Figure 6 shows a further schematic representation of a device according to the invention with a flow breaker 9 and annular slot nozzle 10. This figure shows the same functional features as in Figure 1. The housing 1 has a housing base 2 and a housing cover 3. The feed line 6 supplies the carrier gas with nanoparticulate catalyst precursor. The catalyst carrier is moved within the housing 1 by a rotatable transport shaft 4 with one or more circulation devices 5 arranged on the transport shaft 4. A flow breaker 9 is arranged in the upper part of the housing 1. The carrier gas enters the interior via an annular nozzle 10. The annular nozzle 10 is supplied with carrier gas via the feed line 6 and distributes the carrier gas evenly over the entire interior. For this purpose, the annular nozzle 10 can, for example, be located against the inner wall of the housing 1.

[0043] Figure 7 shows a schematic representation of an annular nozzle 10 for a device according to the invention. The annular nozzle 10 can be a ring-slot nozzle in the form of a sleeve. The carrier gas reaches the annular nozzle 10 via the supply line 6 and is then guided into the interior of the housing 1.

Claims

Patent claims 1. A device for loading catalyst supports by depositing a nanoparticulate catalyst precursor from a carrier gas onto a surface of the catalyst supports, characterized in that the device comprises at least: a) a housing (1), wherein the housing (1) extends from a housing base (2) to a housing cover (3) at a height H and perpendicular thereto with a width B, wherein a ratio of the height and width of the housing (1), calculated as the height of the housing (1) divided by the width of the housing (1), is greater than or equal to 1 and less than or equal to 20; b) a rotatable transport shaft (4) arranged inside and on a central axis of the housing (1) with one or more circulation devices (5) arranged on the transport shaft (4), wherein the circulation devices (5) are designed to transport the catalyst support both axially and radially within the housing (1);and c) a feed (6) for the carrier gas containing the nanoparticulate catalyst precursor arranged in a lower region of the housing (1), wherein the lower region of the housing (1) extends from the housing bottom (2) into the housing (1) to less than or equal to 30% of the height of the housing (1); 2. Device according to claim 1, wherein the rotatable transport shaft (4) is designed with one or more circulation devices (5) arranged on the transport shaft (4) in the form of a conveyor screw (11), wherein the diameter of the circulation devices (5) of the conveyor screw (11) relative to the inner diameter of the housing (1) at the respective height position, calculated according to the maximum height-related diameter of the circulation device (5) divided by the height-related inner diameter of the housing (1), is greater than or equal to 0.60 and less than or equal to 0.

98.

3. Device according to one of the preceding claims, wherein one or more flow breakers (9) are arranged between an inner wall of the housing (1) and the transport shaft (4).

4. Device according to one of the preceding claims, wherein the supply (6) for the carrier gas containing the nanoparticulate catalyst precursor takes place via one or more nozzles (10), wherein a maximum nozzle opening of the nozzle (10) is greater than or equal to 10% and less than or equal to 85% based on the average particle size of the carrier material.

5. Device according to claim 4, wherein the nozzles (10) are arranged on the inner wall of the housing (11), wherein an angular orientation of a nozzle outlet is greater than or equal to 10° and less than or equal to 60° with respect to a vector extending axially in the direction of the housing base (2) within the inner wall at this point.

6. Device according to one of claims 1 to 4, wherein the supply (6) for the carrier gas containing the nanoparticulate catalyst precursor takes place via the rotatable transport shaft (4).

7. Device according to one of the preceding claims, wherein the housing (1) is at least partially conical.

8. Device according to one of the preceding claims, wherein the device comprises a discharge (7) arranged in an upper region of the housing (11) for the catalyst support at least partially superficially loaded with a nanoparticulate catalyst precursor and the carrier gas depleted of the nanoparticulate catalyst precursor, wherein the upper region of the housing (1) extends from the lower edge of the housing cover (3) to less than or equal to 30% of the height of the housing (1) into the housing (1).

9. Device according to claim 8, wherein a compacting unit is arranged upstream of the discharge (7) of the catalyst carrier loaded with a catalyst, wherein the compacting unit is designed to compact the catalyst carrier loaded with catalyst into agglomerates.

10. A process for the preparation of supported catalysts, characterized in that a catalyst support is contacted with a nanoparticulate catalyst precursor in a carrier gas in a device according to one of the preceding claims.

11. Use of a device according to one of claims 1 to 9 for loading catalyst supports with an average particle size determined by laser light scattering of greater than or equal to 0.1 pm and less than or equal to 1 cm.

12. Use according to claim 11, wherein the catalyst supports have an average particle size, determined by laser light scattering, of greater than or equal to 250 pm and less than or equal to 1 cm.

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