Improved epoxidation catalyst

Abstract

A first aspect of the invention relates to a catalyst molding comprising hollow crystals of a zeolitic material having framework type MFI, wherein the framework of the zeolitic material comprises, preferably consists of, Ti, Si, and O, wherein the catalyst molding comprises (a) pores with a pore diameter in the range of from 0.01 to 0.05 micrometers; and (b) pores with a pore diameter in the range of from > 0.05 to 0.1 micrometers, wherein the ratio of the cumulative intrusion volume of the pores of b) to the cumulative intrusion volume of the pores of a) is ≥1:1, wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06. In a second aspect, the invention is directed to the use of the catalyst molding according to the first aspect of the invention.

Description

[0001] 240835W001

[0002] Improved Epoxidation Catalyst

[0003] TECHNICAL FIELD

[0004] A first aspect of the invention relates to a catalyst molding comprising hollow crystals of a zeolitic material having framework type MFI, wherein the framework of the zeolitic material comprises, preferably consists of, Ti, Si, and 0, wherein the catalyst molding comprises (a) pores with a pore diameter in the range of from 0.01 to 0.05 micrometers; and (b) pores with a pore diameter in the range of from > 0.05 to 0.1 micrometers, wherein the ratio of the cumulative intrusion volume of the pores of b) to the cumulative intrusion volume of the pores of a) is >1:1, wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06. In a second aspect, the invention is directed to the use of the catalyst molding according to the first aspect of the invention.

[0005] INTRODUCTION

[0006] Titanium containing zeolitic materials of structure type MFI are known to be efficient catalysts including, for example, epoxidation reactions. In such industrial-scale processes, typically carried out in continuous mode, these zeolitic materials are usually employed in the form of moldings which, in addition to the catalytically active zeolitic material, comprise a suitable binder.

[0007] WO 2014 / 076625 A1 relates to zeolitic materials having an MFI, MEL, and / or MWW-type framework structure comprising trivalent elements such as aluminum. DE 3047798 A1 describes titanium modified crystalline porous silica, US 6,008,389 A relates to noble metal containing titanium silicalites, US 2004 / 0054199 A1 is directed to modification of zeolitic materials or shaped bodies comprising zeolitic materials by water treatment. WO 2013 / 160345 A1 refers to use of structure directing agents in synthesis of zeolitic materials.

[0008] US 2015 / 0118149 A1 and ON 115974094 A relate to a titanium silicalite molecular sieves and their synthesis. ON 115920958 A relates to a modification method of a titanium-silicon molecular sieve and application thereof, wherein the titanium-silicon molecular sieve is treated with a treatment liquid, the treatment liquid being a mixture of cyclic imine, quaternary ammonium salt, organic amine salt and water, the titanium-silicon molecular sieve can be TS-1.

[0009] WO 2015 / 029055 A1 relates to the field of forming or shaping of titanium silicalite (TS-1) catalysts. It is disclosed therein that a TS-1 material can be shaped by means of an operation such as extrusion. WO 2020 / 074586 A1 relates to a molding comprising a zeolitic material having framework type MFI, and discloses a process for preparing propylene oxide in the presence of a catalyst comprising said molding. R. Wang et al. give an overview on hollow MFI-type zeolites in their review on "Fundamental Understanding and Catalytic Applications of Hollow MFI-type Zeolites” in Catalysis Today 2022. WO 2015 / 059171 A1 discloses a molding for a hydrophobic zeolitic material and process for its production. 240835W001

[0010] -2- There however remains a need for the provision of improved catalyst moldings, in particular with regard to their catalytic efficiency in epoxidation reactions. It was a further object of the present invention to provide an improved process for the epoxidation of propylene with hydrogen peroxide as oxidizing agent, allowing for a very high propylene oxide selectivity.

[0011] DETAILED DESCRIPTION

[0012] Thus, it was an object of the present invention to provide a novel catalyst molding comprising a zeolitic material having framework type MFI, wherein the catalyst molding has improved properties in view of catalytic epoxidation reactions, especially in view of the epoxidation of propylene.

[0013] Surprisingly, it was found that such a catalyst molding exhibiting said advantageous characteristics can be provided if the zeolitic material having framework type MFI has crystals having cavities therein, herein called "hollow crystals”, the zeolitic material comprising such hollow crystals being called a "hollow zeolite”, and if the catalyst molding comprises two sorts of pores within specific pore diameter ranges in a specific ratio. In particular, it has surprisingly been found that a catalyst molding can be provided which shows, if used as a catalyst in an epoxidation reaction of propylene to propylene oxide, significantly increased propylene oxide selectivity, and further exhibits excellent life time properties, i.e. a very low deactivation rate.

[0014] 1staspect - catalyst molding

[0015] Therefore, the present invention relates in a first aspect to a catalyst molding comprising hollow crystals of a zeolitic material having framework type MFI, wherein the framework of the zeolitic material comprises, preferably consists of, Ti, Si, and 0, wherein the catalyst molding comprises

[0016] a) pores with a pore diameter in the range of from 0.01 to 0.05 micrometers; and

[0017] b) pores with a pore diameter in the range of from > 0.05 to 0.1 micrometers,

[0018] wherein the ratio of the cumulative intrusion volume of the pores of b) to the cumulative intrusion volume of the pores of a) is >1:1,

[0019] wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06.

[0020] It is preferred that the catalyst molding has a ratio of the cumulative intrusion volume of the pores of b) to the cumulative intrusion volume of the pores of a) in the range of from 1:1 to 5: 1 , more preferably in the range of from 1.05: 1 to 4:1, more preferably in the range of from 1.1:1 to 3.5:1, more preferably in the range of from 1.2:1 to 3.0:1, wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06.

[0021] So called "hollow zeolites” are known in the art and are materials that comprise crystals of a zeolitic material with closed cavities within the crystals, wherein the volume of said cavities is several orders of magnitude greater than the 240835W001

[0022] -3-volume of the largest sphere which may be included in the zeolite framework structure of the zeolitic material. Preferably, the volume of the largest sphere which may be included in the zeolite framework structure of the zeolitic material is computed according to the method described in "A geometric solution to the largest-free-sphere problem in zeolite frameworks", M.D. Foster, I. Rivin, M.M.J. Treacy and 0. Delgado Friedrichs, Micropor. Mesopor. Mat., 90,32-38, 2006. Several hollow zeolites, such as, for example, hollow titanium silicate (HTS) are commercially available. Hollow zeolites are of interest due to their superior diffusion characteristic and catalytic performance in many heterogeneously catalytic reactions over non-hollow zeolitic materials (see, for example, C. Pagis et al., Chem. Mater, 2016, Vol. 28, pages 5205-5223; Ch. Xia et al., in "Zeolites - Useful Minerals”, chapter 6, Editor: C. Belviso, InTechOpen (Print ISBN978-953-51 -2576-1), August 24, 20216; R. Wang et al., Fundamental Understanding and Catalytic Applications of Hollow MFI-type Zeolites, Catalysis Today, 2022, Vol. 405-406, pages 111-124).

[0023] It is preferred that the catalyst molding's hollow crystals of the zeolitic material have cavities with an average area equivalent circle diameter (ECD) in the range of from 10 to 50 nm, determined by transmission electron microscopy (TEM) according to Reference Example 1.3. The average area equivalent circle diameter is number based.

[0024] Preferably, the catalyst molding's hollow crystals of the zeolitic material have cavities with a D50 value of the area equivalent circle diameter (ECD) in the range of from 10 to 40 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0025] It is preferred that the catalyst molding's hollow crystals of the zeolitic material have cavities with a D10 value of the area equivalent circle diameter (ECD) in the range of from 5 to 25 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0026] Preferably, the catalyst molding's hollow crystals of the zeolitic material have cavities with a D90 value of the area equivalent circle diameter (ECD) in the range of from 40 to 80 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0027] Crystal size

[0028] It is preferred that the catalyst molding's hollow crystals of the zeolitic material have an average area equivalent circle diameter (ECD) in the range of from 150 to 200 nm, determined by transmission electron microscopy (TEM) according to Reference Example 1.3. The average area equivalent circle diameter is number based.

[0029] Preferably, the hollow crystals of the zeolitic material have a D50 value of the area equivalent circle diameter (ECD) in the range of from 140 to 210 nm, determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0030] It is preferred that the catalyst molding's hollow crystals of the zeolitic material have a D10 value of the area equivalent circle diameter (ECD) in the range of from 100 to 170 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3. 240835W001

[0031] -4- Preferably, the catalyst molding's hollow crystals of the zeolitic material have a D90 value of the area equivalent circle diameter (ECD) in the range of from 180 to 240 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0032] Ratio of crystal size to cavity size

[0033] It is preferred that the catalyst molding's hollow crystals of the zeolitic material have a ratio AAEco(crys-tals) : AAECD(cavities) of the average area equivalent circle diameter (ECD) of the crystals AAECD (crystals) to the average area equivalent circle diameter (ECD) of the hollow cavities AAECD(cavities) in the range of form 2:1 to 15:1, wherein the average area equivalent circle diameter (ECD) of the hollow crystals AAEco(crystals) and of the cavities thereof AAECD(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3. Each average area equivalent circle diameter is number based.

[0034] Preferably, the hollow crystals of the zeolitic material have a ratio D50Eco(crystals) : D50Eco(cavities) of the D50 value of the area equivalent circle diameter (ECD) of the hollow crystals D50Eco(crystals) to the D50 value of the area equivalent circle diameter (ECD) of the cavities D50Eco(cavities) in the range of from 2.1:1 to 14:1, wherein the D50 value of the area equivalent circle diameter (ECD) of the hollow crystals D50Eco(crystals) and the D50 value of the area equivalent circle diameter (ECD) of the cavities D50Eco(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0035] It is preferred that the catalyst molding's hollow crystals of the zeolitic material have a ratio D10Eco(crys-tals) : DIOEco(cavities) of the D10 value of the area equivalent circle diameter (ECD) of the hollow crystals DIOEco(crystals) to the D10 value of the area equivalent circle diameter (ECD) of the cavities DIOEco(cavities) in the range of from 20:1 to 35:1, wherein the D10 value of the area equivalent circle diameter (ECD) of the hollow crystals DIOEco(crystals) and the D10 value of the area equivalent circle diameter (ECD) of the cavities DIOEco(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0036] It is preferred that the catalyst molding's hollow crystals of the zeolitic material have a ratio of the D90 value D90Eco(crystals) : D90Eco(cavities) of the area equivalent circle diameter (ECD) of the hollow crystals D90Eco(crys-tals) to the D90 value of the area equivalent circle diameter (ECD) of the cavities D90Eco(cavities) in the range of from 4.5:1 to 6:1, wherein the D90 value of the area equivalent circle diameter (ECD) of the hollow crystals D90Eco(crystals) and the D90 value of the area equivalent circle diameter (ECD) of the cavities D90Eco(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0037] Larger pores

[0038] As indicated above, the catalyst molding comprises

[0039] a) pores with a pore diameter in the range of from 0.01 to 0.05 micrometers; and

[0040] b) pores with a pore diameter in the range of from > 0.05 to 0.1 micrometers,

[0041] wherein the ratio of the cumulative intrusion volume of the pores of b) to the cumulative intrusion volume of the pores of a) is >1:1. 240835W001

[0042] -5-

[0043] It is preferred that the catalyst molding has also

[0044] c) pores with a pore diameter > 0.1 micrometers, wherein the ratio of the cumulative intrusion volume of the pores of c) to the cumulative intrusion volume of the pores of b) is < 1:100, wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06. Thus, the catalyst molding is essentially free of pores with a pore diameter > 0.1 micrometers.

[0045] Preferably, the catalyst molding has a total pore volume in the range of from 0.3 to 1.2 ml / g, more preferably in the range of from 0.4 to 1.1 ml / g, more preferably in the range of from 0.5 to 1.0 ml / g, wherein the total pore volume is preferably determined according to Reference Example 1.2.

[0046] Preferably, the catalyst molding has an average crush strength in the range of from 2 to 30 N, more preferably in the range of from 3 to 10 N, wherein the crush strength is preferably determined according to Reference Example 1.4.

[0047] It is preferred that the catalyst molding further comprises one or more oxidic binders, wherein the one or more oxidic binders are preferably selected from the group consisting of inorganic binders, wherein the one or more binders more preferably comprise one or more sources of a metal oxide and / or of a metalloid oxide, more preferably one or more sources of a metal oxide and / or of a metalloid oxide selected from the group consisting of silica, alumina, titania, zirconia, lanthana, magnesia, and mixtures and / or mixed oxides of two or more thereof, more preferably from the group consisting of silica, alumina, titania, zirconia, magnesia, silica-alumina mixed oxides, silica-titania mixed oxides, sil-ica-zirconia mixed oxides, silica-lanthana mixed oxides, silica-zirconia-lanthana mixed oxides, alumina-titania mixed oxides, alumina-zirconia mixed oxides, alumina-lanthana mixed oxides, alumina-zirconia-lanthana mixed oxides, titania-zirconia mixed oxides, and mixtures and / or mixed oxides of two or more thereof, more preferably from the group consisting of silica, alumina, silica-alumina mixed oxides, and mixtures of two or more thereof, wherein more preferably the one or more oxidic binders comprise one or more sources of silica, wherein more preferably the one or more binders consist of one or more sources of silica.

[0048] It is preferred that the catalyst molding comprises the one or more oxidic binders, calculated as the oxide, in an amount in the range of from 5 to 55 weight-%, more preferably of from 10 to 50 weight-%, more preferably of from 12 to 45 weight-%, more preferably of from 15 to 35 weight-%, based on the weight of the catalyst molding.

[0049] Preferably, from 95 to 100 weight-%, more preferably from 98 to 100 weight-%, more preferably from 99 to 100 weight-%, more preferably from 99.5 to 100 weight-%, more preferably from 99.9 to 100 weight-% of the catalyst molding consist of the zeolitic material and the one or more oxidic binders.

[0050] It is preferred that the catalyst molding has a Ti content in the range of from 0.4 to 1.85 weight-%, more preferably in the range of from 0.5 to 1.7 weight-%, more preferably in the range of from 0.6 to 1.5 weight-%, more preferably in the range of from 0.7 to 1.3 weight-%, calculated as elemental Ti and based on the sum of the weights of the zeolitic material and optionally the one or more oxidic binders, preferably determined by elemental analysis. 240835W001

[0051] -6- It is preferred that the catalyst molding has a Si content in the range of from 36 to 48 weight-%, preferably in the range of from 38 to 46 weight-%, more preferably in the range of from 39 to 46 weight-%, calculated as elemental Si and based on the sum of the weights of the zeolitic material and optionally the one or more oxidic binders, preferably determined by elemental analysis.

[0052] 2ndaspect - use

[0053] In a second aspect, the invention relates to the use of the catalyst molding according to the first aspect of the invention, as a catalyst and / or catalyst component for the conversion of propylene to propylene oxide with hydrogen peroxide in an aqueous medium comprising methanol and an additive, wherein the additive comprises one or more potassium cation(s), preferably at least one potassium salt of a phosphorous oxyacid, more preferably one or more of dipotassium hydrogen phosphate and a potassium salt of etidronic acid.

[0054] All details, embodiments and preferred embodiments described above in the section related to the catalyst molding of the first aspect apply also to the second aspect of the invention.

[0055] Regarding said use, it is preferred that the additive comprises or is a potassium salt of etidronic acid, more preferably comprises or is a potassium salt of etidronic acid of the formula KxH^Eti, wherein “Eti" means etidronate and x is a number in the range of 1.5-3.

[0056] The present invention is further illustrated by the following set of embodiments and combinations of embodiments resulting from the dependencies and back-references as indicated. In particular, it is noted that in each instance where a range of embodiments is mentioned, for example in the context of a term such as "The catalyst molding of any one of embodiments 1 to 4", every embodiment in this range is meant to be explicitly disclosed for the skilled person, i.e. the wording of this term is to be understood by the skilled person as being synonymous to "The catalyst molding of any one of embodiments 1, 2, 3 and 4". Further, it is explicitly noted that the following set of embodiments represents a suitably structured part of the general description directed to preferred aspects of the present invention, and, thus, suitably supports, but does not represent the claims of the present invention.

[0057] 1. A catalyst molding comprising hollow crystals of a zeolitic material having framework type MFI, wherein the framework of the zeolitic material comprises, preferably consists of, Ti, Si, and 0, wherein the catalyst molding comprises

[0058] a) pores with a pore diameter in the range of from 0.01 to 0.05 micrometers; and

[0059] b) pores with a pore diameter in the range of from > 0.05 to 0.1 micrometers,

[0060] wherein the ratio of the cumulative intrusion volume of the pores of b) to the cumulative intrusion volume of the pores of a) is >1:1,

[0061] wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06.

[0062] 2. The catalyst molding of embodiment 1 , wherein the ratio of the cumulative intrusion volume of the pores of b) to the cumulative intrusion volume of the pores of a) is in the range of from1:1 to 5:1, preferably in the range 240835W001

[0063] -7- of from 1.05:1 to 4:1, more preferably in the range of from 1.1:1 to 3.5:1, more preferably in the range of from 1.2:1 to 3.0:1, wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06.

[0064] 3. The catalyst molding of embodiment 1 or 2, wherein the hollow crystals of the zeolitic material have cavities with an average area equivalent circle diameter (ECD) in the range of from 10 to 50 nm, determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0065] 4. The catalyst molding of any one of embodimentsl to 3, wherein the hollow crystals of the zeolitic material have cavities with a D50 value of the area equivalent circle diameter (ECD) in the range of from 10 to 40 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0066] 5. The catalyst molding of any one of embodimentsl to 4, wherein the hollow crystals of the zeolitic material have cavities with a D10 value of the area equivalent circle diameter (ECD) in the range of from 5 to 25 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0067] 6. The catalyst molding of any one of embodimentsl to 5, wherein the hollow crystals of the zeolitic material have cavities with a D90 value of the area equivalent circle diameter (ECD) in the range of from 40 to 80 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0068] 7. The catalyst molding of any one of embodimentsl to 6, wherein he hollow crystals of the zeolitic material have an average area equivalent circle diameter (ECD) in the range of from 150 to 200 nm, determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0069] 8. The catalyst molding of any one of embodimentsl to 7, wherein the hollow crystals of the zeolitic material have a D50 value of the area equivalent circle diameter (ECD) in the range of from 140 to 210 nm, determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0070] 9. The catalyst molding of any one of embodimentsl to 8, wherein the hollow crystals of the zeolitic material have a D10 value of the area equivalent circle diameter (ECD) in the range of from 100 to 170 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0071] 10. The catalyst molding of any one of embodimentsl to 9, wherein the hollow crystals of the zeolitic material have a D90 value of the area equivalent circle diameter (ECD) in the range of from 180 to 240 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0072] 11. The catalyst molding of any one of embodimentsl to 10, wherein the hollow crystals of the zeolitic material have a ratio AAEco(crystals) : AAEco(cavities) of the average area equivalent circle diameter (ECD) of the crystals AAEco(crystals) to the average area equivalent circle diameter (ECD) of the hollow cavities AAEco(cavities) in the range of form 2:1 to 15:1, wherein the average area equivalent circle diameter (ECD) of the hollow crystals AAEco(crystals) and of the cavities thereof AAEco(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3. 240835W001

[0073] -8- 12. The catalyst molding of any one of embodimentsl to 11, wherein the hollow crystals of the zeolitic material have a ratio D50Eco(crystals) : D50ECD(cavities) of the D50 value of the area equivalent circle diameter (ECD) of the hollow crystals D50Eco(crystals) to the D50 value of the area equivalent circle diameter (ECD) of the cavities D50ECD(cavities) in the range of from 2.1:1 to 14:1, wherein the D50 value of the area equivalent circle diameter (ECD) of the hollow crystals D50Eco(crystals) and the D50 value of the area equivalent circle diameter (ECD) of the cavities D50ECD(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0074] 13. The catalyst molding of any one of embodimentsl to 12, wherein the hollow crystals of the zeolitic material have a ratio DIOEco(crystals) : DIOEco(cavities) of the D10 value of the area equivalent circle diameter (ECD) of the hollow crystals DIOEco(crystals) to the D10 value of the area equivalent circle diameter (ECD) of the cavities DIOECD(cavities) in the range of from 20:1 to 35:1, wherein the D10 value of the area equivalent circle diameter (ECD) of the hollow crystals DIOEco(crystals) and the D10 value of the area equivalent circle diameter (ECD) of the cavities DIOEco(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0075] 14. The catalyst molding of any one of embodimentsl to 13, wherein the hollow crystals of the zeolitic material have a ratio of the D90 value D90Eco(crystals) : D90Eco(cavities) of the area equivalent circle diameter (ECD) of the hollow crystals D90Eco(crystals) to the D90 value of the area equivalent circle diameter (ECD) of the cavities D90Eco(cavities) in the range of from 4.5:1 to 6:1, wherein the D90 value of the area equivalent circle diameter (ECD) of the hollow crystals D90Eco(crystals) and the D90 value of the area equivalent circle diameter (ECD) of the cavities D90Eco(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

[0076] 15. The catalyst molding of any one of embodiments 1 to 14, the catalyst molding having

[0077] c) pores with a pore diameter > 0.1 micrometers, wherein the ratio of the cumulative intrusion volume of the pores of c) to the cumulative intrusion volume of the pores of b) is < 1:100, wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06.

[0078] 16. The catalyst molding of any one of embodiments 1 to 15 having a total pore volume in the range of from 0.3 to 1.2 ml / g, preferably in the range of from 0.4 to 1.1 ml / g, more preferably in the range of from 0.5 to 1.0 ml / g, wherein the total pore volume is preferably determined according to Reference Example 1.2.

[0079] 17. The catalyst molding of any one of embodiments 1 to 16, having an average crush strength in the range of from 2 to 30 N, preferably in the range of from 3 to 10 N, wherein the crush strength is preferably determined according to Reference Example 1.4.

[0080] 18. The catalyst molding of any one of embodiments 1 to 17 further comprising one or more oxidic binders, wherein the one or more oxidic binders are preferably selected from the group consisting of inorganic binders, wherein the one or more binders more preferably comprise one or more sources of a metal oxide and / or of a metalloid oxide, more preferably one or more sources of a metal oxide and / or of a metalloid oxide selected 240835W001

[0081] -9- from the group consisting of silica, alumina, titania, zirconia, lanthana, magnesia, and mixtures and / or mixed oxides of two or more thereof, more preferably from the group consisting of silica, alumina, titania, zirconia, magnesia, silica-alumina mixed oxides, silica-titania mixed oxides, silica-zirconia mixed oxides, silica-lanthana mixed oxides, silica-zirconia-lanthana mixed oxides, alumina-titania mixed oxides, alumina-zirconia mixed oxides, alumina-lanthana mixed oxides, alumina-zirconia-lanthana mixed oxides, titania-zirconia mixed oxides, and mixtures and / or mixed oxides of two or more thereof, more preferably from the group consisting of silica, alumina, silica-alumina mixed oxides, and mixtures of two or more thereof, wherein more preferably the one or more oxidic binders comprise one or more sources of silica, wherein more preferably the one or more binders consist of one or more sources of silica.

[0082] 19. The catalyst molding of embodiment 18 comprising the one or more oxidic binders, calculated as the oxide, in an amount in the range of from 5 to 55 weight-%, more preferably of from 10 to 50 weight-%, more preferably of from 12 to 45 weight-%, more preferably of from 15 to 35 weight-%, based on the weight of the catalyst molding.

[0083] 20. The catalyst molding of embodiment 18 or 19, wherein from 95 to 100 weight-%, more preferably from 98 to 100 weight-%, more preferably from 99 to 100 weight-%, more preferably from 99.5 to 100 weight-%, more preferably from 99.9 to 100 weight-% of the catalyst molding consist of the zeolitic material and the one or more oxidic binders.

[0084] 21. The catalyst molding of any one of embodiments 1 to 20, having a Ti content in the range of from 0.4 to 1.85 weight-%, preferably in the range of from 0.5 to 1.7 weight-%, more preferably in the range of from 0.6 to 1.5 weight-%, more preferably in the range of from 0.7 to 1.3 weight-%, calculated as elemental Ti and based on the sum of the weights of the zeolitic material and optionally the one or more oxidic binders, preferably determined by elemental analysis.

[0085] 22. The catalyst molding of any one of embodiments 1 to 21 , having a Si content in the range of from 36 to 48 weight-%, preferably in the range of from 38 to 46 weight-%, more preferably in the range of from 39 to 46 weight-%, calculated as elemental Si and based on the sum of the weights of the zeolitic material and optionally the one or more oxidic binders, preferably determined by elemental analysis.

[0086] 23. Use of the catalyst molding according to any one of embodiments 1 to 22, as a catalyst and / or catalyst component for the conversion of propylene to propylene oxide with hydrogen peroxide in an aqueous medium comprising methanol and an additive, wherein the additive comprises one or more potassium cation(s), preferably at least one potassium salt of a phosphorous oxyacid, more preferably dipotassium hydrogen phosphate and a potassium salt of etidronic acid.

[0087] 24. The use according to embodiment 23, wherein the additive comprises or is a potassium salt of etidronic acid, more preferably comprises or is a potassium salt of etidronic acid of the formula KxH^Eti, wherein “Eti" means etidronate and x is a number in the range of 1.5-3. 240835W001

[0088] -10- The present invention is further illustrated by the following reference examples, comparative examples, and examples.

[0089] EXPERIMENTAL SECTION

[0090] Reference Example 1 : Determination methods

[0091] Reference Example 1.1 : Determination of the propylene epoxidation catalytic

[0092] performance

[0093] In a continuous epoxidation reaction setup, a vertically arranged tubular reactor (length: 1.4 m, outer diameter 10 mm, internal diameter: 4 mm; material: stainless austenitic steel of type 1.4571) equipped with a cooling jacket for temperature control, was charged with 15 g of the moldings of the respective TS-1 catalyst in the form of strands as described in the respective Example and Comparative Examples below. The area within the reactor covered by the moldings was called the catalyst bed. The remaining reactor volume was filled with inert material (steatite spheres, 2 mm in diameter) to a height of about 5 cm at the lower end of the reactor and the remainder at the top end of the reactor. The temperature in the epoxidation zone (=catalyst bed) was measured with a tenfold thermocouple (ten thermoelements, each made of stainless austenitic steel of type 1.4571). Six of the ten thermoelements were located in the first half of the catalyst bed.

[0094] Feed streams were provided for all starting materials methanol, propylene and hydrogen peroxide, as well as for the respective additive dipotassium phosphate (K2HPO4, DKP) or dipotassium salt of hydroxyethylidene diphosphonic acid (dipotassium etidronate, K2HEDP)respectively. Through the reactor, the starting materials were passed with the following flow rates: methanol (49 g / h); hydrogen peroxide (9 g / h; employed as aqueous hydrogen peroxide solution with a hydrogen peroxide content of 40 weight- %); propylene (7 g / h; polymer grade).

[0095] Via the cooling medium passed through the cooling jacket, an average temperature in the epoxidation zone was adjusted in the range of from 35 to 70 °C so that the hydrogen peroxide conversion, determined on the basis of the reaction mixture leaving the reactor, was essentially constant at 90 %. The pressure within the reactor was held constant at 21 bar(abs), and the reaction mixture - apart from the fixed-bed catalyst - consisted of one single liquid phase.

[0096] The reactor effluent stream downstream the pressure control valve was collected, weighed and analyzed. Organic components were analyzed in two separate gas-chromatographs. The hydrogen peroxide content was determined colorimetrically using the titanyl sulfate method. The selectivity for propylene oxide was determined relative to hydrogen peroxide (S(H2O2) to PO), and was calculated as 100 times the ratio of moles of propylene oxide in the effluent stream (mol (PO produced)) divided by the moles of hydrogen peroxide in the feed (mol (H2O2 feed)) as follows in formula (1): 240835W001

[0097] -11- S(H2O2) to PO = Produced)x

[0098] v 1mol (H2O2 feed)v 1

[0099] Reference Example 1.2: Determination of the total pore volume and

[0100] of the cumulative intrusion volume

[0101] The total pore volume and the cumulative intrusion volume were determined via intrusion mercury porosimetry according to DIN 66133 from 1993-06.

[0102] Reference example 1.3: Determination of the size of the cavities of the hollow crystals of the zeolitic material and of the crystal size of the hollow crystals of the zeolitic material

[0103] The size of the hollow crystals and of the cavities of the hollow crystals of the zeolitic material in the molding was determined via Transmission Electron Microscopy (TEM). Samples for TEM were prepared on ultra-thin carbon TEM carriers.

[0104] The extrudates were grinded in a mortar and the powder was therefore dispersed in ethanol. A drop of the dispersion was applied between two glass objective slides and gently dispersed. The TEM carrier film was subsequently dipped on the resulting thin film. The samples were imaged by TEM using a Themis Z machine (Thermo-Fisher, Waltham, USA) operated at 300 keV under bright-field as well as high angle annular dark-field scanning TEM (HAADF-STEM) conditions.

[0105] The size of the cavities was evaluated by manual segmentation using imaged (Imaged) with the ParticleSizer plugin (ParticleSizer (imagej.net)).

[0106] For the primary crystal size analysis, the open source software package imaged (Imaged) was used. TEM images with a magnification of 24000x were analyzed for at least 150 particles. The particles were manually selected as polygons. The results of Area and Aspect ratio (AR) were used for calculations, wherein for said calculations, Excel by Microsoft was used. Area was converted to area equivalent circle diameter (ECD). The statistical descriptors of ECD and AR were calculated using all selected particles per sample, wherein the average area equivalent circle diameter was determined as the sum of the area equivalent circle diameter of all particles divided by the number of all particles (number based average area equivalent circle diameter). This applied for both the average area equivalent circle diameter with respect to the cavities of the hollow crystals of the zeolitic material and for the size of the crystals.

[0107] Reference Example 1.4: Determination of the Crush Strength

[0108] The crush strength as referred to in the context of the present invention is to be understood as having been determined via a crush strength test machine Z2.5 / TS1S, supplier Zwick GmbH & Co., D-89079 Ulm, Germany. As to fundamentals of this machine and its operation, reference is made to the respective instructions handbook "Register 1 : Betriebsanleitung I Sicherheitshandbuch fiir die Material-Prufmaschine Z2.5 / TS1S ", version 1.5, December 2001 by 240835W001

[0109] -12- Zwick GmbH & Co. Technische Dokumentation, August-Nagel-Strasse 11, D-89079 Ulm, Germany. The machine was equipped with a fixed horizontal table on which the molding (preferably strand) was positioned, with the longitudinal axis of the molding (preferably strand) parallel to the horizontal table. A plunger with rectangular surface, having a width of 3 mm and depth of 10 mm, which was freely movable in vertical direction actuated the molding (preferably strand) against the fixed table. The apparatus was operated with a preliminary force of 0.5 N, a shear rate under preliminary force of 10 mm / min and a subsequent testing rate of 1.6 mm / min. The vertically movable plunger was connected to a load cell for force pick-up and, during the measurement, moved toward the fixed turntable on which the molding (preferably strand) to be investigated is positioned, thus actuating the molding (preferably strand) against the table. The plunger was applied to the moldings (preferably strands) with the short edge of the plunger parallel to the longitudinal axis of the moldings (preferably strands). With said machine, a given molding (preferably strand) as described below was subjected to an increasing force via the plunger until a break occurs. The force for breaking was referred to as the crush strength of the molding (preferably strand).

[0110] Controlling the experiment was carried out by means of a computer which registered and evaluated the results of the measurements. The values obtained were the mean value of the measurements for 25 moldings (preferably strands) in each case. Thus, the obtained mean values are also referred to herein as average crush strength.

[0111] Comparative Example 1 : Preparing a catalyst molding comprising zeolitic material having framework structure MFI with hollow crystals

[0112] CE1.1 Preparation of hollow TS-1

[0113] A titanium silicalite-1 (TS-1) powder comprising hollow crystals was prepared according to the following recipe: TECS (tetraethyl orthosilicate) (300 kg) were loaded into a stirred tank reactor at room temperature and stirring (100 r.p.m.) was started. In a second vessel, 60 kg TECS and 13.5 kg TEOT (tetraethyl orthotitanate) were first mixed and then added to the TECS in the first vessel. Subsequently, another 360 kg TECS were added to the mixture in the first vessel. Then, the content of the first vessel was stirred for 10 min before 950 g TPAOH (tetrapropylammonium hydroxide) were added. Stirring was continued for 60 min. Ethanol released by hydrolysis was separated by distillation at a bottoms temperature of 95 °C. 300 kg water were then added to the content of the first vessel, and water in an amount equivalent to the amount of distillate was further added. The obtained mixture was stirred for 1 h. Crystallization was performed at 175 °C within 12 h at autogenous pressure. The obtained titanium silicalite-1 hollow crystals were separated, dried, and calcined at a temperature of 500 °C in air for 6 h.

[0114] CE1.2 Post treatment of hollow TS-1 powder

[0115] 1072 g deionized water were provided in a beaker. Then, 424 g tetrapropylammonium hydroxide (as an aqueous solution comprising 40 weight-% tetrapropylammonium hydroxide) were added under stirring. Subsequently, 200 g of a TS-1 powder comprising hollow crystals prepared according to Reference Example 12.1 were added. This mixture was homogenized for 30 min. The mixture was then transferred in an autoclave. The mixture was hydrothermally treated at 170 °C for 24 hours. The resulting suspension was filtrated, and the solid residue obtained was washed with deionized water. The resulting solid was dried overnight at room temperature. The yield was 150 g. 240835W001

[0116] -13- 3000 g of aqueous nitric acid (10 weight- % HNO3 in water) were provided in a glass beaker. Under stirring, 150 g of the dried solid were added thereto. The resulting suspension - while being stirred at 250 rpm - was refluxed at 100 °C for 1 hour. For work-up, the suspension was filtrated, and the solid residue was washed with deionized water. The resulting solid was dried in air and subsequently calcined in air in an oven according to the following procedure:

[0117] 1. heating up to 120 °C within 1 hour

[0118] 2. drying at 120 °C for 4 hours

[0119] 3. heating up to 500 °C within 190 min

[0120] 4. calcining at 500 °C for 5 hours.

[0121] The solid was then grinded. The yield was 121 g. The resulting powder had a Si content of 44 g / 100 g, and a Ti content of 1.7 g / 100 g, each determined by elemental analysis.

[0122] CE1.3 Shaping of hollow TS-1 powder

[0123] 50 g of the zeolitic material of CE1.2 and 2 g Walocel™ (Walocel MW 15000 GB, Wolff Cellulosics GmbH &Co. KG, Germany) were provided in a kneader and kneaded for 5 minutes. Then, 50.4 g of an aqueous dispersion comprising 25 weight-% polystyrene and 25 weight-% silica (colloidal Ludox® AS 40 was used as basis for the dispersion) were added. After 10 minutes, 0.67 g polyethylene oxide (PEG, Union Carbide, PolyOX Coagulant) were added and the mixture was kneaded. After further 10 minutes, 41.65 g of a colloidal silica (Ludox® AS 40) were added. Subsequently, the addition of de-ionized water was started in portions of 10 ml every 10 minutes to result in a total addition of water of 100 mL. The total kneading time was 45 minutes. After completion of the water addition, the kneaded mass was subjected to shaping. For shaping, the kneaded mass was extruded at a pressure of 150 bar(abs) to give strands with a circular cross-section having a diameter of 1.7 mm. The strands were then dried and calcined in air according to the following program:

[0124] 1. heating within 60 minutes to a temperature of 120 °C;

[0125] 2. keeping the temperature of 120 °C for 4 h;

[0126] 3. heating within 185 minutes to a temperature of 490 °C;

[0127] 4. keeping the temperature of 490 °C for 5 h.

[0128] The yield was 55 g.

[0129] CE1.4 Water treatment of shaped hollow TS-1

[0130] 36 g of the strands prepared according to CE1.3 were mixed in four portions of each 9 g with 180 g deionized water per portion. The resulting mixtures were heated to a temperature of 145 °C for 8 h in an autoclave. Thereafter, the obtained water-treated strands were separated and was sieved over a 0.8 mm sieve. The obtained strands were then washed with deionized water and pre-dried in a stream of nitrogen at ambient temperature. The washed and predried strands were subsequently dried and calcined in air according to the following program:

[0131] 1. heating within 60 minutes up to 120 °C;

[0132] 2. keeping the temperature of 120 °C for 4 h; 240835W001

[0133] -14- 3. heating within 165 minutes up to 450 °C;

[0134] 4. keeping the temperature of 450 °C for 2 h.

[0135] The yield was 36.2 g. The resulting catalyst moldings had a Si content of 45 g / 100 g, and a Ti content of 1.3 g / 100 g, each determined by elemental analysis.

[0136] Total pore volume of the catalyst moldings, comprising hollow TS-1 crystals, as determined according to Reference Example 1.2 as well as ratio of the cumulative intrusion volume of the pores with pore diameter in the range of from > 0.05 to 0.1 micrometers to the cumulative intrusion volume of the pores with a pore diameter in the range of from 0.01 to 0.05 micrometers are indicated hereinbelow in Table 1. Furthermore, crush strength of the strands determined according to Reference Example 1.4, runtime of the catalyst moldings in the test according to Reference Example 1.1 with the additive being dipotassium phosphate (K2HPO4, DKP, concentration of 130 micromoles K+per mol of hydrogen peroxide), as well as temperature required for maintaining the peroxide conversion essentially constant at 90 %, PO selectivity as achieved in the test according to Reference Example 1.1 is indicated hereinbelow in T able 1. A plot of cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter is shown in Fig. 1.

[0137] Comparative Example 2: Preparing a catalyst molding comprising zeolitic material having framework structure MFI

[0138] A TS-1 zeolite was prepared with tetrapropylammonium template as described in DE 19939416 A1. Shaping was done as described above in CE1.3 and water treatment was done as described above in CE1.4, giving catalyst moldings.

[0139] Total pore volume of the catalyst moldings as determined according to Reference Example 1.2 as well as ratio of the cumulative intrusion volume of the pores with pore diameter in the range of from > 0.05 to 0.1 micrometers to the cumulative intrusion volume of the pores with a pore diameter in the range of from 0.01 to 0.05 micrometers are indicated hereinbelow in Table 1. Furthermore, crush strength of the strands determined according to Reference Example 1.4, runtime of the catalyst moldings in the test according to Reference Example 1.1 with the additive being dipotassium phosphate (K2HPO4, DKP, concentration of 130 micromoles K+per mol of hydrogen peroxide), as well as temperature required for maintaining the peroxide conversion essentially constant at 90 %, PO selectivity as achieved in the test according to Reference Example 1.1 is indicated hereinbelow in Table 1. A plot of cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter is shown in Fig. 2.

[0140] Comparative Example 3: Preparing a catalyst molding comprising zeolitic material having framework structure MFI

[0141] CE3.1 TS-1 synthesis 240835W001

[0142] -15- For the synthesis of the TS-1 zeolite samples using the allyl-tripropylammonium template, the following procedure was used: tetraethylorthosilicate (TEOS) (500 g) was added together with tetraethylortotitanat (TEOTi) (15 g) to a round bottom flask. 5200 g of a 20 wt. % of allyl-tripropylammonium hydroxide (ATPAOH) solution displaying a molar ratio N-(2-propen-1-yl)-tri-n-propylammonium : N-(1-propen-1-yl)-tri-n-propylammonium of 95 : 5 was then added under stirring to the flask containing the Si and Ti source. A yellow blurry solution is obtained after mixing all the components. The mixture was further kept under stirring for 1 h until the hydrolysis of the silica and titanium sources was finished and the temperature of the mixture was held constant at 54 °C. The ethanol resulting from the hydrolysis of TEOS and TEOTi was separated by distillation from the synthesis mixture at 95 °C for 2 h, during which the solution was continuously stirred with 100 rpm.

[0143] After the distillation, 600 g of distilled water were added to (about 530 g) of the distillate and the solution was stirred for another hour at room temperature. Finally, the suspension was transferred to a 2.5 L stainless steel autoclave equipped with mechanical stirring. The autoclave was heated to 175 °C and kept for 16 h under continuous stirring (200 rpm).

[0144] After 16 h the autoclave was cooled to room temperature and distilled water was added to the suspension in a volumetric ratio of 1 : 1 (pH of the resulting solution was about 12). The suspension was then filtered on a Buchner filter and the solid was washed several times with water. The white solid was dried for 4 h at 120 °C and calcined for 5 h at 490 °C under air, using the following calcination program: 60 min to 120 °C, 240 min at 120 °C, 370 min from 120 to 490 °C and 300 min at 490 °C.

[0145] CE3.2 Shaping

[0146] 90 g of TS-1 , 3.6 g of Methylcellulose (Walocel®), and 30 g of Aerosil® 200 were mixed together, wherein at first % of the aforementioned components were mixed together and kneaded for 5 min, after which the remaining % together with 50 ml of distilled water were added. After 10 min, 91 g of a polystyrene dispersion (33.1 wt.-% in water; average particle size 47.3 nm; pH = 9.3) were continuously added under further kneading of the mixture. After 10 min, 1.2 g of polyethylene oxide were then added. After further kneading, 35 g of distilled water were then added, wherein 30 ml were added after 10 min and after a further 10 min the remaining 5 ml were then added, such that the total duration of kneading was 50 min. The mixture was then extruded under a pressure of 110 bar into strands with a diameter of 1.5 mm, which were then dried for 4 hours at 120°C and finally calcined at 490°C for 5 hours using the following calcination program: 60 min to 120 °C, 240 min at 120 °C, 370 min from 120 to 490 °C and 300 min at 490 °C, to afford extruded strands.

[0147] The shaped strands were subjected to water treatment as in CE1.4, giving catalyst moldings.

[0148] Total pore volume of the catalyst moldings as determined according to Reference Example 1.2 as well as ratio of the cumulative intrusion volume of the pores with pore diameter in the range of from > 0.05 to 0.1 micrometers to the cumulative intrusion volume of the pores with a pore diameter in the range of from 0.01 to 0.05 micrometers are indicated hereinbelow in Table 1. Furthermore, crush strength of the strands determined according to Reference Example 1.4, runtime of the catalyst moldings in the test according to Reference Example 1.1 with the additive being dipotassium 240835W001

[0149] -16-phosphate (K2HPO4, DKP, concentration of 130 micromoles K+per mol of hydrogen peroxide), as well as temperature required for maintaining the peroxide conversion essentially constant at 90 %, PO selectivity as achieved in the test according to Reference Example 1.1 is indicated herein below in Table 1. A plot of cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter is shown in Fig. 3.

[0150] Comparative Example 4: Preparing a catalyst molding comprising zeolitic material having framework structure MFI comprising hollow crystals

[0151] Based on the general teaching of M. Liu et al. "Highly Selective Epoxidation of Propylene in a Low-Pressure Continuous Slurry Reactor and the Regeneration of Catalyst, 54 g of commercially available hollow zeolitic HTS-1 (Titanium Silicalite RT-03 of Zhejiang TWRD New Material Co., Ltd., CN), 36 g sepiolite with a content of approx. 13 weight- % Mg, CAS 63800-37-3, Aldrich) and 10 g methylcellulose (Walocel MW 15000 GB, Wolff Cellulosics GmbH & Co. KG, Germany) were provided in a kneader and kneaded for 5 minutes. Then, 40 mL of water were added and the mixture was further kneaded for 15 minutes. After that, further 25 mL of water were added and the mixture kneaded for further 10 minutes. The total kneading time was 30 minutes. The kneaded mass was extruded at a pressure of 150 bar(abs) to give strands having a circular cross-section with a diameter of 1.7 mm. Subsequently, the extruded strands were dried and calcined in air according to the following program:

[0152] 1. heating within 40 minutes up to a temperature of 80 °C;

[0153] 2. keeping the temperature of 80 °C for 6 h;

[0154] 3. heating within 265 minutes to a temperature of 650 °C;

[0155] 4. keeping the temperature of 650 °C for 6 h.

[0156] The yield was 77.9 g. The resulting strands had a Si content of 40 g / 100 g, a Mg content of 5.8 g / 100 g, and a Ti content of 1.1 g / 100 g, each determined by elemental analysis.

[0157] Total pore volume of the catalyst moldings, comprising hollow TS-1 crystals, as determined according to Reference Example 1.2 as well as ratio of the cumulative intrusion volume of the pores with pore diameter in the range of from > 0.05 to 0.1 micrometers to the cumulative intrusion volume of the pores with a pore diameter in the range of from 0.01 to 0.05 micrometers are indicated herein below in Table 1. Furthermore, crush strength of the strands determined according to Reference Example 1.4, runtime of the catalyst moldings in the test according to Reference Example 1.1 with the additive being dipotassium phosphate (K2HPO4, DKP, concentration of 130 micromoles K+per mol of hydrogen peroxide), as well as temperature required for maintaining the peroxide conversion essentially constant at 90 %, PO selectivity as achieved in the test according to Reference Example 1.1 is indicated herein below in Table 1. A plot of cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter is shown in Fig. 4.

[0158] Comparative Example 5: Preparing a catalyst molding comprising zeolitic material having framework structure MFI 240835W001

[0159] -17- TS-1 powder of company TWRD China (product name TD 126) was shaped as described above in CE1.3 and water treatment was done as described above in CE1.4, giving catalyst moldings.

[0160] Total pore volume of the catalyst moldings as determined according to Reference Example 1.2 as well as ratio of the cumulative intrusion volume of the pores with pore diameter in the range of from > 0.05 to 0.1 micrometers to the cumulative intrusion volume of the pores with a pore diameter in the range of from 0.01 to 0.05 micrometers are indicated hereinbelow in Table 1. Furthermore, crush strength of the strands determined according to Reference Example 1.4, runtime of the catalyst moldings in the test according to Reference Example 1.1 with the additive being dipotassium phosphate (K2HPO4, DKP, concentration of 130 micromoles K+per mol of hydrogen peroxide), as well as temperature required for maintaining the peroxide conversion essentially constant at 90 %, PO selectivity as achieved in the test according to Reference Example 1.1 is indicated hereinbelow in Table 1. A plot of cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter is shown in Fig. 5.

[0161] Comparative Example 6: Preparing a catalyst molding comprising zeolitic material having framework structure MFI

[0162] CE6.1 TS-1 synthesis

[0163] Tetraethoxy silane (TEOS, 4000 kg) was loaded into a stirred tank reactor at room temperature and stirring (750 r.p.m.) was started. 254 kg tetraethoxy titanate (TEOT) were filled in the reactor under stirring and then 4889 kg of TEOS were added. Then, 7300 kg ATPAOH (isomer ratio allyl : propenyl = 88 : 12, 40 wt.-% in water) were added. Stirring was continued for 60 min. Ethanol released by hydrolysis was separated by distillation at a bottoms temperature of 86 °C. 16000 kg distilled water were then added to the content of the first vessel, and water in an amount equivalent to the amount of distillate was further added. The obtained mixture was stirred for 1 h. Crystallization was performed at 175 °C within 5 h at autogenous pressure. The obtained titanium silicalite-1 crystals were separated, dried, and calcined in a rotary furnace at a temperature of 550 °C in air using a residence time of 2 h. The characterization of the sample obtained from reference example 5 by elemental analysis (for Ti and Si), the BET surface area determined according to DIN 66131, and the water adsorption capacity.

[0164] CE6.2 Shaping

[0165] 105.3 g of TS-1 and 4 g of Methylcellulose (Walocel®) were mixed together and kneaded for 5 min, after which 100.7 g of a polystyrene dispersion (33.1 wt.-% in water; average particle size 47.3 nm; pH = 9.3) were continuously added under further kneading of the mixture. After 10 min, 1.33 g of polyethylene oxide were then added. After a further 10 min, 70 g of Ludox® AS 40 (40 wt.-% silica in water) were added in a continuous manner. After further kneading, 40 g of distilled water were then added, wherein 10 ml were added after 10 min, 10 ml after a further 5 in, 10 ml after a further 5 min, and finally 10 ml after a further 5 min, such that the total duration of kneading was 55 min. The mixture was then extruded under a pressure of 120 bar into strands with a diameter of 1.9 mm, which were then dried for 4 hours at 120°C and finally calcined at 490°C for 5 hours using the following calcination program: 60 min to 120 °C, 240 min at 120 °C, 370 min from 120 to 490 °C and 300 min at 490 °C, to afford extruded strands. 240835W001

[0166] -18- The shaped strands were subjected to water treatment as in CE1.4, giving catalyst moldings.

[0167] Total pore volume of the catalyst moldings as determined according to Reference Example 1.2 as well as ratio of the cumulative intrusion volume of the pores with pore diameter in the range of from > 0.05 to 0.1 micrometers to the cumulative intrusion volume of the pores with a pore diameter in the range of from 0.01 to 0.05 micrometers are indicated hereinbelow in Table 1. Furthermore, crush strength of the strands determined according to Reference Example 1.4, runtime of the catalyst moldings in the test according to Reference Example 1.1 with the additive being dipotassium phosphate (K2HPO4, DKP, concentration of 130 micromoles K+per mol of hydrogen peroxide), as well as temperature required for maintaining the peroxide conversion essentially constant at 90 %, PO selectivity as achieved in the test according to Reference Example 1.1 is indicated hereinbelow in Table 1. A plot of cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter is shown in Fig. 6.

[0168] Example 1 : Preparing a catalyst molding according to the invention comprising hollow crystals

[0169] E1.1 TS-1 synthesis of hollow TS-1

[0170] For the gel preparation, 600 g tetraethylorthosilicate (TEOS) were filled into a beaker. Under stirring 13.5 g tetrabutylorthotitanate (TiBOTI; Aldrich) dissolved in 50 g of Isopropnaol was added slowly within 5 min. The solution was further stirred for 90 min. Then, a solution of 360 g de-ionized water and 264 g aqueous tetrapropylammonium hydroxide (TPAOH; 40 weight-% in water) was added under stirring (200 rpm). The resulting mixture was further mixed for 120 min. The mixture had a pH of 12.4. determined with a pH sensitive glass electrode.

[0171] The synthesis gel was then transferred into an autoclave. The synthesis gel was heated under stirring in the autoclave to a temperature of 170 °C and stirred at said temperature for 48 h under autogenous pressure. The resulting suspension was then worked-up. To this effect, the resulting solids were separated and washed by centrifugation. Subsequently, the solids were dried in an oven in air at 120 °C for 10 h and then calcined in air at 500 °C for 5 h, wherein the heating rate for calcining was 2 °C / min, resulting in a TS-1 powder.

[0172] E1.2 post treatment of hollow TS-1

[0173] 804 g deionized water and 323 g of an aqueous solution comprising 40 weight-% tetrapropylammonium hydroxide were provided in a beaker. Then, 150 g of a TS-1 powder prepared according to E1.1 above were added under stirring (200 rpm, anchor stirrer). This mixture was stirred for 60 min, and then transferred into an autoclave. The mixture was then heated to 170 °C under stirring and stirred for 90 h at 170 °C under autogenous pressure. The obtained suspension was worked-up as follows: The suspension was filled into beakers and centrifuged for 60 min with 4000 rpm. The solids were dried in an oven for 10 h at 120 °C and then calcined for 5 h at 500 °C (heating rate 2 °C / min) in air, resulting in a TS-1 material having a Ti content of 1.2 g / 100 g, determined by elemental analysis.

[0174] E1.2 Shaping of hollow TS-1 240835W001

[0175] -19- 100.0 g of the zeolitic material and 4.0 g Walocel™ (Walocel MW 15000 GB, Wolff Cellulosics GmbH & Co. KG, Germany) were provided in a kneader and mixed for 5 minutes. Then, 111.0 g of polystyrene (33 wt.-% aqueous dispersion) were added, and the resulting mixture kneaded for 10 minutes. Then, 1.33 g of polyethylene oxide (PEG) were added, and the resulting mixture kneaded for 10 minutes. Then, 83.3 g of an aqueous suspension comprising 40 weight-% colloidal silica (Ludox® AS 40) were added and the resulting mixture kneaded for 10 minutes.

[0176] Subsequently, 25.0 g deionized water were added, and the resulting mixture kneaded for 15 minutes.

[0177] After that, the kneaded mass was subjected to shaping. For shaping, the kneaded mass was extruded at a pressure of 150 bar(abs) to give strands with a circular cross-section having a diameter of 1.9 mm. The strands were then dried in an oven for 4 h at 120 °C and then calcined in air for 5 h at 490 °C (heating rate: 2 °C / min).

[0178] E1.3 Water treatment

[0179] 40.0 g of the prepared strands were loaded into an autoclave. Then, 600 g deionized water were added. The resulting mixture was heated to a temperature of 145 °C for 8 h in an autoclave. Thereafter, the obtained water-treated strands were separated and sieved over a 800 m sieve. The obtained strands were then washed with deionized water and dried in an oven for 4 h at 120 °C (heating rate: 2 °C / min) in air and then calcined for 2 h at 450 °C (heating rate: 2 °C / min) in air.

[0180] The resulting catalyst moldings, comprising hollow crystals, had a Ti content of 0.9 g / 100 g, determined by elemental analysis.

[0181] Total pore volume of the catalyst moldings, comprising hollow crystals, as determined according to Reference Example 1.2 as well as ratio of the cumulative intrusion volume of the pores with pore diameter in the range of from > 0.05 to 0.1 micrometers to the cumulative intrusion volume of the pores with a pore diameter in the range of from 0.01 to 0.05 micrometers are indicated herein below in Table 1. Furthermore, crush strength of the strands determined according to Reference Example 1.4, runtime of the catalyst moldings in the test according to Reference Example 1.1 with the additive being dipotassium hydrogen phosphate (DKP, concentration of 130 micromoles K+per mol of hydrogen peroxide), as well as temperature required for maintaining the peroxide conversion essentially constant at 90 %, PO selectivity as achieved in the test according to Reference Example 1.1 is indicated herein below in Table 1. A plot of cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter is shown in Fig. 7.

[0182] Example 2: Preparing a catalyst molding according to the invention comprising hollow crystals

[0183] E2.1 hollow TS-1 synthesis

[0184] A titanium silicalite-1 with hollow crystals powder was prepared according to the following recipe: 500 g TEOS (tetraethyl orthosilicate) and 15 g TEOTi (tetraethyl orthotitanate) were loaded into a four-neck flask at room temperature 240835W001

[0185] -20-and stirring (200 rpm) was started. Then, 220 g of an aqueous solution comprising 40 weight-% TPAOH (tetrapropylammonium hydroxide) and 300 g of deionized water were added. The pH of the resulting solution was 14.21, determined with a pH sensitive glass electrode. Stirring was continued for 60 min, whereby the temperature of the mixture rose to 60 °C. Ethanol released by hydrolysis was separated by distillation at a bottoms temperature of 95 °C, obtaining about 540 g ethanol and a gel. The pH of the gel was 12.34, determined with a pH sensitive glass electrode. Subsequently, the gel was cooled down to 40 °C under stirring and 540 g of deionized water were added. The pH of the obtained mixture was 12.01, determined with a pH sensitive glass electrode. Crystallization was performed in an autoclave under stirring at 175 °C within 16 h and 20 min at autogenous pressure.

[0186] The obtained suspension was worked-up as follows. The suspension was diluted 1 : 1 with deionized water under stirring (200 rpm, Teflon anchor stirrer) and precipitated with 10% HNO3 (approx. 130 g) at pH 7.31, determined with a pH sensitive glass electrode, and filtered off through a porcelain suction filter (blue belt filter). The filter cake was washed 3 times with 1000 ml deionized water, dried in an oven for 4 h at 120 °C and calcined for 5 h at 490 °C (heating rate 2 °C / min) in air.

[0187] The yield was 148 g. The resulting powder had a Si content of 43 g / 100 g, and a Ti content of 1.9 g / 100 g, each determined by elemental analysis.

[0188] E2.2 Post treatment of hollow TS-1

[0189] 750.0 g deionized water and 300 g of an aqueous solution comprising 40 weight-% tetrapropylammonium hydroxide were provided in a beaker. Then, 140 g of a TS-1 powder prepared according to E2.1 were added under stirring (200 rpm, anchor stirrer). This mixture was stirred for 60 min, and then transferred in an autoclave. The mixture was then heated to 170 °C under stirring and stirred for 84 h at 170 °C under autogenous pressure. The obtained suspension was worked-up as follows. The suspension was filled into beakers and centrifuged for 60 min with 4000 rpm. The solids were dried in an oven for 10 h at 120 °C and then calcined for 5 h at 490 °C (heating rate 2 °C / min) in air.

[0190] The yield was 121 g. The resulting powder had a Ti content of 1.8 g / 100 g, determined by elemental analysis.

[0191] E2.3 Shaping

[0192] 1 00.0 g of the zeolitic material of E2.2 and 4.0 g Walocel™ (Walocel MW 15000 GB, Wolff Cellulosics GmbH & Co. KG, Germany) were provided in a kneader and mixed for 5 minutes. Then, 111.0 g of polystyrene (33 wt.-% aqueous dispersion) were added, and the resulting mixture kneaded for 10 minutes. Then, 1.33 g of polyethylene oxide (PEC) were added, and the resulting mixture kneaded for 10 minutes. Then, 83.3 g of an aqueous suspension comprising 40 weight-% colloidal silica (Ludox® AS 40) were added and the resulting mixture kneaded for 10 minutes.

[0193] Subsequently, 25.0 g deionized water were added, and the resulting mixture kneaded for 15 minutes.

[0194] After that, the kneaded mass was subjected to shaping. For shaping, the kneaded mass was extruded at a pressure of 150 bar(abs) to give strands with a circular cross-sectional profile having a diameter of 1.9 mm. The strands were then dried in an oven for 4 h at 120 °C and then calcined in air for 5 h at 490 °C (heating rate: 2 °C / min). 240835W001

[0195] -21- The yield was 124 g. The obtained material, comprising hollow crystals, had a Ti content of 1.3 g / 100 g determined by elemental analysis.

[0196] E2.4 Water treatment of shaped hollow TS- 1

[0197] 50.0 g of the strands prepared according to E2.3 were loaded into an autoclave. Then, 750 g deionized water were added. The resulting mixture was heated to a temperature of 145 °C for 8 h in an autoclave. Thereafter, the obtained water-treated strands were separated and sieved over a 800 m sieve. The obtained strands were then washed with deionized water and dried in an oven for 4 h at 120 °C (heating rate: 2 °C / min) in air and then calcined for 2 h at 450 °C (heating rate: 2 °C / min) in air.

[0198] The resulting catalyst moldings, comprising hollow crystals, had a Ti content of 1.4 g / 100 g determined by elemental analysis.

[0199] Total pore volume of the catalyst moldings as determined according to Reference Example 1.2 as well as ratio of the cumulative intrusion volume of the pores with pore diameter in the range of from > 0.05 to 0.1 micrometers to the cumulative intrusion volume of the pores with a pore diameter in the range of from 0.01 to 0.05 micrometers are indicated hereinbelow in Table 1. Furthermore, crush strength of the strands determined according to Reference Example 1.4, runtime of the catalyst moldings in the test according to Reference Example 1.1 with the additive being dipotassium etidronate (K2HEDP, concentration of 308 micromoles K+per mol of hydrogen peroxide), as well as temperature required for maintaining the peroxide conversion essentially constant at 90 %, PO selectivity as achieved in the test according to Reference Example 1.1 is indicated hereinbelow in Table 1. A plot of cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter is shown in Fig. 8. The TEM based data relative to the cavities of the hollow crystals in the molding are shown in Fig. 10. The TEM based data relative to the hollow crystals in the molding are shown in Fig. 12.

[0200] Example 3: Preparing a catalyst molding according to the invention comprising hollow crystals

[0201] E3.1 hollow TS-1 synthesis

[0202] For the gel preparation, 600 g tetraethylorthosilicate (TEOS) and 18 g tetraethylorthotitanate (TEOTi; Merck) were filled into a beaker. Then, a solution of 360 g de-ionized water and 264 g aqueous tetrapropylammonium hydroxide (TPAOH; 40 weight-% in water) was added under stirring (200 rpm). The resulting mixture had a pH of 14,14, determined with a pH sensitive glass electrode. The mixture was hydrolyzed at room temperature for 60 min during which the temperature rose to 60 °C. The mixture had a pH of 13,23, determined with a pH sensitive glass electrode, then. Afterwards the ethanol was distilled off until the sump reached a temperature of 95 °C.

[0203] The synthesis gel was then cooled to 40 °C under stirring and 650 g de-ionized water added thereto.

[0204] The synthesis gel was then transferred into an autoclave. The synthesis gel was heated under stirring in the autoclave to a temperature of 175 °C and stirred at said temperature for 16 h under autogenous pressure. The resulting 240835W001

[0205] -22-suspension was then worked-up. To this effect, the resulting suspension was diluted with de-ionized water, wherein the weight ratio of the suspension to de-ionized water was 1:1. Then, about 145 g nitric acid (10 weight-% in water) were added and the resulting mixture had a pH of 7.28, determined with a pH sensitive glass electrode. The obtained solids were filtered off and washed four times with de-ionized water (each time 1000 ml de-ionized water were used). Subsequently, the solids were dried in an oven in air at 120 °C for 16 h and then calcined in air at 490 °C for 5 h, wherein the heating rate for calcining was 2 °C / min.

[0206] 804 g de-ionized water were provided in a beaker. Then, 323 g tetrapropylammonium hydroxide (as an aqueous solution comprising 40 weight-% tetrapropylammonium hydroxide) were added under stirring. Subsequently, 23,5 g of Urea were added under stirring. Finally, 150 g of the TS-1 zeolite produced above were added. This mixture was homogenized for 30 min. The mixture was then transferred in an autoclave, where it was hydrothermally treated at 170 °C for 90 hours. The resulting solids were separated via centrifugation, and the solid residue obtained was washed with deionized water. The resulting solid material was heated in air within 60 min to a temperature of 120 °C and dried at said temperature for 10 h. Then, the resulting solid material was calcined at 500 for 5 h °C, wherein the heating rate for calcining was 2 °C / min.

[0207] E3.2 Shaping of hollow TS- 1

[0208] 100 g of the zeolitic material from E3.1 , 4 g of a cellulose derivative (Zusoplast C39), and 4 g of a polyvinyl acetate compound (Optapix PAG 60) were provided in a kneader, and the resulting mixture kneaded for 5 minutes. Then, 51 ,25 g of an aqueous suspension comprising 40 weight-% colloidal silica (Ludox® AS 40) were added and the resulting mixture kneaded for 10 minutes. Subsequently, 60 g deionized water were added, and the resulting mixture kneaded for 10 minutes. Then, 1 g of polyethylene oxide (PEG) were added, and the resulting mixture kneaded for 10 minutes. Subsequently, 30 g deionized water were added, and the resulting mixture kneaded for 10 minutes.

[0209] After that, the kneaded mass was subjected to shaping. For shaping, the kneaded mass was extruded at a pressure of 150 bar(abs) to give strands with a circular cross-sectional profile having a diameter of 1.9 mm. The strands were then dried in an oven for 4 h at 120 °C and then calcined in air for 5 h at 500 °C (heating rate: 2 °C / min).

[0210] The obtained catalyst moldings, comprising hollow crystals, had a Ti content of 1.0 g / 100 g, a Si content of 46 g / 100 g, each determined by elemental analysis.

[0211] Total pore volume of the catalyst moldings as determined according to Reference Example 1.2 as well as ratio of the cumulative intrusion volume of the pores with pore diameter in the range of from > 0.05 to 0.1 micrometers to the cumulative intrusion volume of the pores with a pore diameter in the range of from 0.01 to 0.05 micrometers are indicated herein below in Table 1. Furthermore, crush strength of the strands determined according to Reference Example 1.4, runtime of the catalyst moldings in the test according to Reference Example 1.1 with the additive being dipotassium etidronate (concentration of 308 micromoles K+per mol of hydrogen peroxide), as well as temperature required for maintaining the peroxide conversion essentially constant at 90 %, PG selectivity as achieved in the test according to Reference Example 1.1 is indicated herein below in T able 1. A plot of cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter is shown in Fig. 9. The TEM based data relative to the 240835W001

[0212] -23-cavities of the hollow crystals in the molding are shown in Fig. 11. The TEM based data relative to the hollow crystals in the molding are shown in Fig. 13.

[0213] Table 1

[0214]

[0215] * hollow TS-1 crystals in the moldings

[0216] It was found that, even if catalyst moldings comprising hollow crystals (see CE1) achieved a certain PO selectivity, as well as catalysts having a ratio (b) to (a) >1 (see CE5) achieved a certain PO selectivity, a catalyst molding with hollow crystals and a ratio (b) to (a) >1:1 (see E1) was superior in view of PO selectivity.

[0217] Short description of the Figures

[0218] Fig. 1 shows the plotted cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter of Comparative Example 1

[0219] Fig.2 shows the plotted cumulative intrusion volume and the first derivative of the cumulative curve respec- tively versus pore diameter of Comparative Example 2

[0220] Fig. 3 shows the plotted cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter of Comparative Example 3 240835W001

[0221] -24- Fig.4 shows the plotted cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter of Comparative Example 4

[0222] Fig. 5 shows the plotted cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter of Comparative Example 5

[0223] Fig. 6 shows the plotted cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter of Comparative Example 6

[0224] Fig. 7 shows the plotted cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter of Example 1

[0225] Fig. 8 shows the plotted cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter of Example 2

[0226] Fig.9 shows the plotted cumulative intrusion volume and the first derivative of the cumulative curve respectively versus pore diameter of Example 3

[0227] Fig. 10 shows the TEM based data relative to the cavities of the hollow crystals in the molding of Example 2

[0228] Fig. 11 shows the TEM based data relative to the cavities of the hollow crystals in the molding of Example 3

[0229] Fig. 12 shows the TEM based data relative to the hollow crystals in the molding of Example 2

[0230] Fig. 13 shows the TEM based data relative to the hollow crystals in the molding of Example 3

[0231] Cited Literature

[0232] WO 2014 / 076625 A1

[0233] DE 3047798 A1

[0234] US 6,008,389 A

[0235] US 2004 / 0054199 A1

[0236] WO 2013 / 160345 A1

[0237] US 2015 / 0118149 A1

[0238] ON 115974094 A

[0239] ON 115920958 A

[0240] WO 2015 / 029055 A1

[0241] WO 2020 / 074586 A1

[0242] WO 2015 / 059171 A1

[0243] M.D. Foster, I. Rivin, M.M.J. Treacy and 0. Delgado Friedrichs, Micropor. Mesopor. Mat., 90,32-38, 2006

[0244] C. Pagis et al., Chem. Mater, 2016, Vol. 28, pages 5205-5223 240835W001

[0245] -25- Ch. Xia et al., "Zeolites - Useful Minerals”, chapter 6, Editor: C. Belviso, InTechOpen (Print ISBN978-953-51 -2576-1), August 24, 20216

[0246] R. Wang et al., "Fundamental Understanding and Catalytic Applications of Hollow MFI-type Zeolites”, Catalysis Today, 2022, Vol. 405-406, pages 111-124

Claims

240835W001-26- Claims1. A catalyst molding comprising hollow crystals of a zeolitic material having framework type MFI, wherein the framework of the zeolitic material comprises, preferably consists of, Ti, Si, and 0, wherein the catalyst molding comprisesa) pores with a pore diameter in the range of from 0.01 to 0.05 micrometers; andb) pores with a pore diameter in the range of from > 0.05 to 0.1 micrometers,wherein the ratio of the cumulative intrusion volume of the pores of b) to the cumulative intrusion volume of the pores of a) is >1:1,wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06;wherein the hollow crystals of the zeolitic material have cavities with an average area equivalent circle diameter in the range of form 10 to 50 nm determined by transmission electron microscopy.

2. The catalyst molding of claim 1 , wherein the ratio of the cumulative intrusion volume of the pores of b) to the cumulative intrusion volume of the pores of a) is in the range of from1:1 to 5:1, preferably in the range of from 1.05:1 to 4:1, more preferably in the range of from 1.1:1 to 3.5:1, more preferably in the range of from 1.2:1 to 3.0:1, wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06.

3. The catalyst molding of claim 1 or 2, wherein the average area equivalent circle diameter (ECD) of the cavities of the hollow crystals of the zeolitic material is determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

4. The catalyst molding of any one of claims 1 to 3, wherein the hollow crystals of the zeolitic material have cavities with a D50 value of the area equivalent circle diameter (ECD) in the range of form 10 to 40 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3;and / or, preferably and;wherein the hollow crystals of the zeolitic material have cavities with a D10 value of the area equivalent circle diameter (ECD) in the range of from 5 to 25 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3;and / or, preferably and;wherein the hollow crystals of the zeolitic material have cavities with a D90 value of the area equivalent circle diameter (ECD) in the range of from 40 to 80 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

5. The catalyst molding of any one of claims 1 to 4, wherein the hollow crystals of the zeolitic material have an average area equivalent circle diameter (ECD) in the range of form 150 to 200 nm, determined by transmission electron microscopy (TEM) according to Reference Example 1.3;240835W001-27- and / or, preferably and;wherein the hollow crystals of the zeolitic material have a D50 value of the area equivalent circle diameter (ECD) in the range of form 140 to 210 nm, determined by transmission electron microscopy (TEM) according to Reference Example 1.3;and / or, preferably and;wherein the hollow crystals of the zeolitic material have a D10 value of the area equivalent circle diameter (ECD) in the range of from 100 to 170 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3;and / or, preferably and;wherein the hollow crystals of the zeolitic material have a D90 value of the area equivalent circle diameter (ECD) in the range of from 180 to 240 nm determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

6. The catalyst molding of any one of claims 1 to 5, wherein the hollow crystals of the zeolitic material have a ratio AAEco(crystals) : AAEco(cavities) of the average area equivalent circle diameter (ECD) of the crystals AAEco(crystals) to the average area equivalent circle diameter (ECD) of the hollow cavities AAEco(cavities) in the range of form 2: 1 to 15: 1 , wherein the average area equivalent circle diameter (ECD) of the hollow crystals AAEco(crystals) and of the cavities thereof AAEco(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

7. The catalyst molding of any one of claims 1 to 6, wherein the hollow crystals of the zeolitic material have a ratio D50Eco(crystals) : D50Eco(cavities) of the D50 value of the area equivalent circle diameter (ECD) of the hollow crystals D50Eco(crystals) to the D50 value of the area equivalent circle diameter (ECD) of the cavities D50Eco(cavities) in the range of from 2.1:1 to 14:1, wherein the D50 value of the area equivalent circle diameter (ECD) of the hollow crystals D50Eco(crystals) and the D50 value of the area equivalent circle diameter (ECD) of the cavities D50Eco(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

8. The catalyst molding of any one of claims 1 to 7, wherein the hollow crystals of the zeolitic material have a ratio DIOEco(crystals) : DIOEco(cavities) of the D10 value of the area equivalent circle diameter (ECD) of the hollow crystals DIOEco(crystals) to the D10 value of the area equivalent circle diameter (ECD) of the cavities DIOEco(cavities) in the range of from 20:1 to 35:1, wherein the D10 value of the area equivalent circle diameter (ECD) of the hollow crystals DIOEco(crystals) and the D10 value of the area equivalent circle diameter (ECD) of the cavities DIOEco(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

9. The catalyst molding of any one of claims 1 to 8, wherein the hollow crystals of the zeolitic material have a ratio of the D90 value D90Eco(crystals) : D90Eco(cavities) of the area equivalent circle diameter (ECD) of the hollow crystals D90Eco(crystals) to the D90 value of the area equivalent circle diameter (ECD) of the cavities240835W001-28- D90Eco(cavities) in the range of from 4.5:1 to 6:1, wherein the D90 value of the area equivalent circle diameter (ECD) of the hollow crystals D90Eco(crystals) and the D90 value of the area equivalent circle diameter (ECD) of the cavities D90ECD(cavities) are each determined by transmission electron microscopy (TEM) according to Reference Example 1.3.

10. The catalyst molding of any one of claims 1 to 9, the catalyst molding havingc) pores with a pore diameter > 0.1 micrometers, wherein the ratio of the cumulative intrusion volume of the pores of c) to the cumulative intrusion volume of the pores of b) is < 1:100, wherein the pore diameter and the cumulative intrusion volume are determined according to DIN 66133 from 1993-06.

11. The catalyst molding of any one of claims 1 to 10 having a total pore volume in the range of from 0.3 to 1.2 ml / g, preferably in the range of from 0.4 to 1.1 ml / g, more preferably in the range of from 0.5 to 1.0 ml / g, wherein the total pore volume is preferably determined according to Reference Example 1.2.

12. The catalyst molding of any one of claims 1 to 11 further comprising one or more oxidic binders, wherein the one or more oxidic binders, calculated as the oxide, are preferably comprised in an amount in the range of from 5 to 55 weight-%, more preferably of from 10 to 50 weight-%, more preferably of from 12 to 45 weight-%, more preferably of from 15 to 35 weight-%, based on the weight of the catalyst molding.

13. Use of the catalyst molding according to any one of claims 1 to 12, as a catalyst and / or catalyst component for the conversion of propylene to propylene oxide with hydrogen peroxide in an aqueous medium comprising methanol and an additive, wherein the additive comprises one or more potassium cation(s), preferably at least one potassium salt of a phosphorous oxyacid.

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