Method for producing organosilanes

Abstract

Methods for making organosilanes by reacting one or more hydridosilanes with one or more halogenated hydrocarbons in the presence of a heterogenous metal catalyst including a support and at least one metal selected from platinum (Pt) and palladium (Pd), and at least one metal selected from gold (Ag) and silver (Au).

Description

[0001] METHOD FOR PRODUCING ORGANOSILANES

[0002] CROSS REFERENCE TO RELATED APPLICATIONS:

[0003] None.

[0004] FIELD:

[0005] The invention is directed toward methods for making organosilancs by reacting one or more hydridosilanes with one or more halogenated hydrocarbons in the presence of a heterogenous metal catalyst including a support and at least one metal selected from: platinum (Pt) and palladium (Pd), and at least one metal selected from: gold (Ag) and silver (Au).

[0006] INTRODUCTION:

[0007] The literature describes a variety of methods for producing organosilanes by dehydrogenation and alkylation or arylation of hydridosilanes. One stated objective is to produce an organosilane reaction product having a relatively higher organo content than the hydridosilane reactant. Such reactions generally involve reacting a hydridosilane with a halogenated hydrocarbon in the presence of a metal catalyst at elevated temperature. Representative examples include: US2902504 which describes the reaction of a hydridosilane with an aryl chloride in the presence of a copper catalyst; US4474976 which describes the reaction of a hydridosilane with a halogenated aromatic compound in the presence of a transition metal catalyst such as rhodium, ruthenium, palladium, osmium, iridium and platinum; US4985580 which describes the reaction of non-halogen containing silane with an alkyl halide in the presence of a halogen-accepting metal; and US12060375 and US2023 / 0141781 which describe the reaction of a hydridosilane with methyl chloride in the presence of an ammonium and / or phosphonium salt. Despite these known techniques there continues to be a need for improved methods of producing organosilanes, including those that provide improved selectivity, conversion, flexibility and / or lower costs.

[0008] SUMMARY:

[0009] The invention includes methods for producing organosilanes including the step of reacting one or more hydridosilanes with one or more halogenated hydrocarbons in the presence of a heterogenous metal catalyst, wherein the heterogenous metal catalyst comprises: a) a support and b) at least one metal selected from: (Group A) platinum and palladium, and at least one metal selected from: (Group B) gold and silver.

[0010] DETAILED DESCRIPTION:

[0011] The heterogenous catalysts used in the present invention include: a) a support and b) at least one metal selected from: (Group A) platinum and palladium, and at least one metal selected from: (Group B) gold and silver. The molar ratio of Group A to Group B metals present in the catalyst is not particularly limited but is generally from 10:1 to 1: 10 and more preferably from 3:1 to 1:3. The Group A and B metals are preferably provided as an alloy or partial alloy and may be combined and / or alloyed with additional metals such as magnesium. While the subject catalysts must include a metal from both Group A and B, multiple metals from both Group A and B may be used in combination. Moreover, multiple (different) species of catalysts meeting the aforementioned criteria may be used in combination. However, in one set of embodiments, the subject catalyst is substantially free of Si metal (Si0) wherein “substantially free” means less than 1 part per hundred of the total metal present in the subject catalyst as prepared.

[0012] Applicable supports for use in preparing the subject catalysts are not particularly limited. Representative examples include carbon (including activated forms), alumina, silica (including precipitated and gel forms), silicon carbide, ceria, graphite, and oxides of aluminum, calcium, magnesium, alumina-magnesia, titanium, and / or zirconium. Alternatively, highly crystalline supports can be used such as crystalline silica and certain zeolites, such as Zeolite Y or Zeolite Beta products. Preferred supports include carbon, alumina and silica.

[0013] Applicable methods for preparing the subject catalysts are not particularly limited and conventional techniques such as incipient wetness impregnation, co-precipitation, sol-gel or physical blending may be used. For example, the subject catalysts may be prepared by impregnating a support with a metal precursor (e.g. metal nitrates, chlorides, carbonyls, acetates, etc.), wherein the term “impregnating” means permeating with a wetted, melted, or molten substance throughout all or a portion of a support, preferably to a point where essentially all of a liquid phase substance is adsorbed, producing a liquid-saturated but non- agglomerated solid. The resulting supported catalyst may then be dried and reduced by heating (preferably under inert conditions) , e.g. for carbon supports at a temperature of from 100°C to 150°C for 1 to 10 hours and for non-carbon supports at a temperature of from 100°C to 600°C for 1 to 10 hours with optional exposure to hydrogen, an inert gas or mixtures thereof. The resulting supported catalyst preferably comprises from 0.1 to 10 wt% of Group A and B metals with the balance comprising the support.

[0014] The reactants of the present method include: i) one or more hydridosilanes represented by:

[0015] RaHbSiXc and ii) one or more halogenated hydrocarbons represented by the formula: R’X’dwherein:

[0016] R and R’ are each independently selected from C1-C6 hydrocarbons. In a subset of embodiments, R and R’ are independently selected from aryl groups (e.g. phenyl) and alkyl groups (e.g. methyl, ethyl, propyl, etc.). In another subset of embodiments, R and R’ are independently selected from: methyl, ethyl and phenyl. In still another subset of embodiments, R and R’ are both methyl. X and X’ are each independently selected from halogens including F, Cl, Br and I and in a subset of embodiments, X and X’ are both Cl. a and c are integers selected from 0, 1, 2 and 3; b is an integer selected from 1, 2, 3 and 4, and d is an integer selected from 1 and 2, with the proviso that a+b+c equal 4. In a subset of embodiments, a and c are integers selected from 1 and 2. In another subset of embodiments, d is 1.

[0017] In one particularly industrially relevant set of embodiments, R and R’ are methyl, X and X’ are Cl, a and c are integers selected from 1 and 2 and d is 1 .

[0018] Representative hydridosilanes include: SiFE, HSiCh, H2SiCl2, HsSiCl, MeHSiCF, Me2HSiCl, Me HSi, MeH2SiCl, Me2H2Si, EtHSiCh, Et2HSiCl, Et3HSi, EtH2SiCl, Et2H2Si, PhHSiCk, PhjHSiCl, Ph sHSi, PhH2SiCl, PhMeHSiCl, and Ph2H2Si, where “Me’' is methyl, “Et” is ethyl and “Ph” is phenyl.

[0019] Representative halogenated hydrocarbons include: methyl chloride (MeCl), chlorobenzene (PhCl) and methylene chloride (CH2C12).

[0020] The aforementioned hydridosilanes and halogenated hydrocarbons are preferably reacted in their gas phase in the presence of the aforementioned solid phase heterogenous metal catalyst at temperatures from 200°C to 500°C and more preferably 200°C to 350°C. While the reaction may be conducted under sub-atmospheric, atmospheric or super-atmospheric pressure conditions, preferred embodiments include pressures of from 0 to 3 bar and more preferably from 0.5 to 2 bar. The residence time for the reaction is typically from 0.5 to 30 seconds but more preferably 1 to 7 seconds. The molar ratio of hydridosilanes to halogenated hydrocarbons is preferably from 10: 1 to 1: 10 and more preferably from 3: 1 to 1:3.

[0021] The subject reaction may be conducted in a continuous, semi-continuous or batch manner within a closed vessel under an inert atmosphere, such as nitrogen gas. Suitable reactor configurations including packed bed, stirred bed, vibrating bed, moving bed, recirculating bed and fluidized bed. After at least partial reaction, reactor effluent may by be condensed and the desired organosilane reaction product may be separated from unreacted hydridosilane and halogenated hydrocarbon reactants using well known separation and / or purification techniques, e.g. distillation. The unreacted reactants may then be recycled to the reaction vessel for subsequent reaction.

[0022] The desired organosilane reaction product possesses increased organic content as compared with the hydridosilane reactant. This is accomplished by way of dehydrogenation and / or dehalogenation of the hydridosilane reactant, e.g. wherein the symbols “b” and / or “c” in the above formula are reduced by at least 1 . Representative examples include: MesSiH / MesSiCl from Me2HSiCl and MeCl, and Me2HSiCl / Me2SiCl2from MeHSiCk and MeCl.

[0023] Many embodiments of the invention have been described and, in some instances, certain embodiments, selections, ranges, components, or other features have been characterized as being “preferred.” Such designations of “preferred” features should in no way be interpreted as an essential or critical aspect of the invention. Expressed ranges specifically include designated end points. EXAMPLES:

[0024] The catalysts used in the following examples were prepared using a conventional wetness impregnation method. Unless otherwise specified, the support material is pre -dried at 120°C and then impregnated with an aqueous solution containing the designated metal precursor(s). The resultant mixture is placed on a hot plate to remove the excess solvent. For the carbon-supported catalysts, the resulting material is further dried in a hot air oven at 120°C for 6 hours and stored in a desiccator until use in the reaction. For other catalysts (e.g. alumina, silica, etc.), the dried material is further calcined at 500°C for 4 hours and stored in a desiccator until use in the reaction.

[0025] Example 1: MeCl Silylation using MeHSiCP over Pd-Ag / C catalyst

[0026] Approximately 1.5g of Pd-Ag / C catalyst (having a 1: 1.3 mol ratio of Pd:Ag and 5wt% total metal content) was placed in the middle of a 3 / 8” diameter, 22” long Inconel reactor with a 2” bed length flanked by two beds of quartz wool. Prior to introducing the reactants, the catalyst underwent reduction under a flow of H2 / N2 (100 SCCM each) at 400°C for four hours. The reactor was subsequently mounted on a vertical high-tcmpcraturc furnace and heated to the temperature designated below at a controlled rate of approximately 10°C / min. McIISiCL was introduced into the reactor via nitrogen bubbling through a stainless-steel bubbler maintained at ambient temperature. Concurrently, methyl chloride (MeCl) gas was directed over the catalyst bed using a mass flow controller. The reactor outlet was connected to a three- way valve assembly, facilitating periodic sample injections to an online gas chromatograph (GC) with a thermal conductivity detector (TCD) and mass spectrometer (MS) for product composition analysis. The pressure of reaction was maintained at 0 psig. The temperature of the reaction is specified below in Table 1. The molar feed ratio of MeHSiCb / McCI was 2. Conversion was calculated as: conversion = 100% x (Feedin-FeedOut) / Feedinand product selectivity was calculated as selectivity; = 100% x Product, / !'! Products). Product Selectivity is reported as a mol% selectivity. The results are reported in Table 1 as an average of four GC measurements over a period of 2 hours.

[0027] Table 1 : Activity (mol % products) over Pd-Ag / C catalyst Example 2: MeCl Silylation using McHSiCE over Pd-Ag / SiCE catalyst

[0028] Approximately 1.3 g of Pd-Ag / SiCE catalyst (having a 1: 1.3 mol ratio of Pd:Ag with 5wt% total metal content) was placed in the middle of a reactor as described in Example 1. Prior to the introduction of the reactants, the catalyst was pre-treated under 50 SCCM of FT and 200 SCCM of N? at 350°C for 4 hours. MeHSiCE was then fed into the reactor using an ISCO pump at atmospheric pressure. MeCl gas was flowed over the catalyst bed using a mass flow controller. Nitrogen gas was added to the reactor as a diluent gas. The reactor was placed in a vertical high-temperature furnace and heated to the designated temperature at a programmed rate (~10°C / min). The reactor outlet was connected through a 3-way valve assembly as described in Example 1. The temperature and pressure of reaction were maintained at 275°C and 0 psig, respectively. The molar feed ratio of MeHSiClVMeCl was 2. The results (time on stream) are reported in Table 2

[0029] Table 2. Activity (time on stream, mol% products) over Pd-Ag / SiCE catalyst.

[0030] Example 3: MeCl Silylation using Me^HSiCl over Pd-Ag / C catalyst

[0031] Example 1 was reproduced under substantially similar conditions using dimethylchlorosilane (MeiHSiCl) rather than MeHSiCI? with a molar feed ratio of MciHSiCI / McCI = 0.53. The results are reported in Tables 3a and 3b as an average of ten GC measurements over a period of 3 hours. Table 3a: Activity (mol% products) over Pd-Ag / C catalyst

[0032] Table 3b: Activity (mol% products) over Pd-Ag / C catalyst

[0033] Example 4: Re-distribution vs Methylation activity

[0034] Example 3 was reproduced under substantially similar reaction conditions using the subject Pd- Ag / C catalyst and Me2HSiCl as a reactant, both with and without MeCl as a reactant. The reactions where then reproduced using a Ru / C metal catalyst. The results are provided in Table 4. Note the significant catalytic incorporation of Me from MeCl (indicated by the increase mol% Me iSiCI ) associated with the subject catalyst as compared with the Ru / C catalyst.

[0035] Table 4: Re-distribution vs Methylation activity (mol%) of Me2HSiCl

[0036] Examples 5-16:

[0037] In the examples 5-16, a series of reactions of methyl chloride (MeCl) and methyldichlorosilane (MeHSiCh) were conducted using various heterogeneous catalysts (specified below in Table 5) prepared according to the previously described procedure. Reactions were conducted by loading approximately 200 mg of catalyst into a reactor tube and loaded into a parallel fixed bed reactor (PFBR). The reactor was argon purged and then the catalysts were reduced at 500°C for 1 hour under a stream of 50 / 50 Ar / H2. The reactor temperature was lowered to 350°C and a 1:1 molar ratio feed of MeHSiCh and MeCl was passed over the catalyst with roughly a 3.5 second residence time. Reactor effluent was sampled on an Agilent GC with an SPB octyl column. Using an ex-situ gas calibration and relative response factors for the FID, mole percent composition were calculated. Product sampling was taken approximately every hour for 5 hours. The data was then averaged over that time to calculate conversion and selectivity which is presented in Table 5. Conversion was calculated as: conversion = 100% X (Feedin-FeedOut) / Feedm and product selectivity was calculated as selectivity: = 100% x Producf / CE Products). Product Selectivity is given as a mol% selectivity.

[0038] Table 5 - Activity (mol% products) over different catalysts Examples 17-37: Mono-metallic Catalysts

[0039] In order to illustrate a particular technical effect of the subject invention, a series of reactions were conducted in substantially the same manner as Examples 5-16 using various mono- metal catalysts specified below in Table 6. The reactants and reactions conditions were substantially similar to those of Examples 5-16. Catalyst preparation was substantially similar to that previously described. The results are provided in Table 6. As shown, the mono-metal catalysts exhibited poor selectivity towards the desired products (Me2HSiCl / Me2SiCh) and high selectivity towards the undesired products (MeSiCE / methane).

[0040] Table 6 - Activity (mol% products) over various monometallic catalysts

[0041] Example 38: MeCl Silylation using HSiCh over Pd-Ag / SiO2catalyst The catalyst of Example 2 (Pd-Ag / SiO2) was tested according to the reaction conditions of

[0042] Example 1 using trichlorosilane (HSiCh) with MeCl as reactants using a molar feed ratio of HSiCh / MeCl =1.5, at a 325°C temperature and a pressure of 0 psig. The results are presented as an average of 8 GC measurements over a period of 4 hours in Table 7.

[0043] Table 7 : Product distribution (Si mol%) from MeCl silylation of HSiCh using Pd-Ag / SiO.

[0044] Example 39: Phenyl Chloride (PhCl) Silylation using MeHSiCk over Pd-Ag / SiO catalyst

[0045] 607 mg of Pd- Ag) / SiC>2 (having a 1 : 1 mol ratio of Pd: Ag and 2 wt% total metal content) catalyst was packed between quartz wool in the center of a Hastelloy-C reactor tube (4.6mm ID, 9.53mm OD). The space upstream and downstream of the catalyst packed bed was filled with quartz chips (1-2 mm OD). A 1 / 16” OD type K thermocouple (Inconel 200 sheath) was used to measure the temperature of the catalyst packed bed. The tube was placed in a 12” heated zone tube furnace containing a metal heating block to ensure isothermality along the packed bed axial direction. The tube was connected to gas connections and heated under Argon gas to 120°C for 2 hours. Afterwards, a 250 ml / min 20% IT- Argon mixture was used to activate the catalyst under the following temperature program: Heat to 175°C and hold for 2 hours, heat to 275°C and hold for 2 hours, heat to 350C and hold for 2 hours, all at 0 psig. After the reduction treatment, the gas was switched back to pure Argon at 50 ml / min and cooled to 300°C. In a glovebox, a 100g mixture of 2: 1 molar ratio of McHSiCCPhCI was loaded into a transfer vessel. This vessel was removed from the glovebox and connected to an inerted Teledyne ISCO pump. The pump was then filled with the vessel contents, which in this test comprised PhCl and MeHSiCh. To run the reaction, the ISCO pump metered 0.025 mL / min into a heated tube (60°C) to be vaporized and combined with an Argon gas stream. The vapor was then fed into the reactor with the following composition: 60 seem Argon, 2.43 seem PhCl, 4.57 seem MeHSiClz- The reactor effluent was quantified using an on-line GC-MS with parallel TCD quantification and MS species identification. After 225 minutes of reaction time, the reactor temperature was increased to 325°C at 0 psig and the resulting performance (time on stream) is listed in Tables 8a and 8b. Table 8a. Activity (time on stream, mol% of products) in the silylation of PhCl using McHSiCh over a Pd-Ag / SiCh catalyst. Table 8b. Activity (time on stream, mol% of products) in the silylation of PhCl using MeHSiCI over a Pd-Ag / SiOz catalyst.

[0046] Example 40: Phenyl Chloride and Methyl Chloride Simultaneous Silylation using McHSiCh over Pd- Ag / SiOz catalyst

[0047] 1.18 g of Pd-Ag / SiOz (having a 1: 1 mol ratio of Pd:Ag and 1 wt% total metal content) catalyst was packed between quartz wool in the center of a Hastelloy-C reactor tube (4.6mm ID, 9.53mm OD). The space upstream and downstream of the catalyst packed bed was filled with quartz chips (1-2 mm OD). A 1 / 16” OD type K thermocouple (Inconel 200 sheath) was used to measure the temperature of the catalyst packed bed. The tube was placed in a 12” heated zone tube furnace containing a metal heating block to ensure isothermality along the packed bed axial direction. The tube was connected to gas connections and heated under Argon gas to 120°C for 2 hours. Afterwards, a 50 ml / min 5% H2-Argon mixture was used to activate the catalyst under the following temperature program: Heat to 175°C and hold for 2 hours, heat to 275°C and hold for 2 hours, heat to 35O°C and hold for 2 hours, all at 5 psig. After the reduction treatment, the gas was switched back to pure Argon at 50 ml / min and cooled to 325°C. In a glovebox, 150 mL of MeHSiOz was loaded into a transfer vessel. In the same glovebox, IL of Phenyl Chloride (PhCl) was loaded into a glass feed bottle equipped with valving to allow for pumping with a 4 psig N2 headspace. These two vessels were connected to the gas manifold feeding the reactor described above. A stream of Argon was bubbled through the MeHSiCh transfer vessel and saturated with its vapors to create a chlorosilane stream. In parallel, the positive displacement pump (Valeo M6 HP) was used to meter Phenyl Chloride into a tee connection in the process. The tee was filled with quartz chips acting as a high surface area interface and swept with a separate Argon stream. The tee was electrically heated to 90°C to allow for vaporization of Phenyl Chloride as it dripped onto the quartz chips. The chlorosilane stream and the phenyl chloride stream were then combined with a stream of Methyl Chloride (MeCl) and Argon to create a combined feed that was fed to the catalyst bed. The combined stream composition varied depending on the objective of the experiment and is noted in Table 9a-c below. These conditions explored various MeCl / PhCl feed ratios The reactor effluent quantified using an on-line GC-MS with parallel TCS quantification and MS species identification. Each process condition performance was aggregated by averaging the GC results from 5 measurements.

[0048] Table 9a shows that higher MeCl / PhCl feed ratios lead to increased conversion of both PhCl and McHSiCP. Table 9b shows the impact of each condition on product selectivity. The presence of MeCl leads to increased yield of Methyl containing products, suggesting parallel reaction pathways between PhCl and MeCl silylation. Tables 9a and 9c also show that the relative proportions of Ph-containing products change as a function of PhCl conversion.

[0049] Table 9a - Reagent conversion at different process conditions. All experiments at 325°C. Each condition result is average of 5 GC measurements at that condition, equivalent to approximately 120 minutes on-stream. Table 9b - Reaction product Silicon selectivities. All experiments at 325°C. Each condition result is average of 5 GC measurements at that condition, equivalent to approximately 120 minutes on-stream.

[0050] Table 9c - Reaction product Phenyl-containing product selectivities. All experiments at 325°C. Each condition result is average of 5 GC measurements at that condition, equivalent to approximately 120 minutes on-stream. Example 41: Phenyl Chloride and Methyl Chloride Simultaneous Silylation using HSiCE over Pd- Ag / SiOz catalyst

[0051] 1.56 g of Pd-AgJ / SiOz (having a 1: 1 mol ratio of Pd:Ag and 1 wt% total metal content) catalyst was packed between quartz wool in the center of a Hastelloy-C reactor tube (4.6mm ID, 9.53mm OD). The space upstream and downstream of the catalyst packed bed was filled with quartz chips (1-2 mm OD). A 1 / 16” OD type K thermocouple (Inconel 200 sheath) was used to measure the temperature of the catalyst packed bed. The tube was placed in a 12” heated zone tube furnace containing a metal heating block to ensure isothermality along the packed bed axial direction. The tube was connected to gas connections and heated under Argon gas to 120°C for 2 hours. Afterwards, a 50 ml / min 5% Hi- Argon mixture was used to activate the catalyst under the following temperature program: Heat to 175°C and hold for 2 hours, heat to 275°C and hold for 2 hours, heat to 35O°C and hold for 2 hours, all at 5 psig. After the reduction treatment, the gas was switched back to pure Argon at 50 ml / min and cooled to 325°C. In a glovebox, 150 mL of HSiCh was loaded into a transfer vessel. In the same glovebox, IL of Phenyl Chloride (PhCl) was loaded into a glass feed bottle equipped with valving to allow for pumping with a 4 psig N headspace. These two vessels were connected to the gas manifold feeding the reactor described above. A stream of Argon was bubbled through the HSiCh transfer vessel and saturated with its vapors to create a chlorosilane stream. In parallel, the positive displacement pump (Valeo M6 HP) was used to meter Phenyl Chloride into a tee connection in the process. The tee was filled with quartz chips acting as a high surface area interface and swept with a separate Argon stream. The tee was electrically heated to 90°C to allow for vaporization of Phenyl Chloride as it dripped onto the quartz chips. The chlorosilane stream and the phenyl chloride stream were then combined with a stream of Methyl Chloride (McCl) and Argon to create a combined feed that was fed to the catalyst bed. The combined stream composition varied depending on the objective of the experiment and is noted in Table lOa-c below. One condition (Condition 5) was also evaluated at 340°C. The reactor effluent quantified using an on-line GC- MS with parallel TCS quantification and MS species identification. Each process condition performance was aggregated by averaging the GC results from 5 measurements.

[0052] Table 10a how different feed ratios lead to different conversion of both PhCl and HSiCh, with MeCl generally enabling higher HSiCh conversion. Table 10b shows the impact of each condition on product selectivity. The presence of MeCl leads to increased yield of methyl containing products, suggesting parallel reaction pathways between PhCl and MeCl silylation.

[0053] Table 10a - Reagent conversion at different process conditions. All experiments at 325°C except Condition 5. Each condition result is average of 5 GC measurements at that condition, equivalent to approximately 120 minutes on-stream. Table 10b - Reaction product Silicon selectivities. All experiments at 325°C except Condition 5 (340°C). Each condition result is average of 5 GC measurements at that condition, equivalent to approximately 120 minutes on-stream.

[0054] Table 10c - Reaction product Phenyl-containing product selectivities. All experiments at 325°C except Condition 5 (340°C). Each condition result is average of 5 GC measurements at that condition, equivalent to approximately 120 minutes on-stream.

Claims

CLAIMS:

1. A method for producing an organosilane reaction product comprising the steps of reacting one or more hydridosilanes with one or more halogenated hydrocarbon in the presence of a heterogenous metal catalyst, wherein: i) the heterogenous metal catalyst comprises: a) a support and b) at least one metal selected from: (Group A) platinum and palladium, and at least one metal selected from: (Group B) gold and silver; ii) the hydridosilanes are represented by the following formula: RaHbSiXciii) the halogenated hydrocarbons are represented by the following formula: R’X’d wherein:R and R’ are each independently selected from: C1-C6 hydrocarbons;X and X’ are each independently selected from halogens; a and c are integers selected from 0, 1. 2 and 3; b is an integer selected from 1. 2, 3 and 4, d is an integer selected from 1 and 2, with the proviso that a+b+c equal 4.

2. The method of any preceding claim where the molar ratio of the metal selected from Group A to Group B is from 10: 1 to 1: 10.

3. The method of any preceding claim wherein the metal selected from Group A comprises palladium and the metal selected from Group B comprises silver.

4. The method of any preceding claim wherein the support is selected from at least one of: carbon, alumina and silica.

5. The method of any preceding claim wherein the support is silica.

6. The method of any preceding claim wherein R and R’ are each independently selected from alkyl and aryl.

7. The method of any preceding claim wherein R and R’ are each independently selected from methyl, ethyl and phenyl.

8. The method of any preceding claim wherein R and R’ are methyl.

9. The method of any preceding claim wherein X and X’ are each independently selected from F, Cl, Br and I.

10. The method of any preceding claim wherein X and X’ are Cl.

11. The method of any preceding claim wherein a and c are integers selected from 1 and 2, and d is 1.

12. The method of any preceding claim wherein R and R’ are methyl, X and X’ are Cl, a and c are integers selected from 1 and 2 and d is 1.

13. The method of any preceding claim wherein the hydridosilanes and halogenated hydrocarbons are in a gas phase during reaction.

14. The method of any preceding claim wherein the hydridosilanes and halogenated hydrocarbons are reacted at a temperature of from 200°C to 500°C.

15. The method of any preceding claim wherein the hydridosilanes and halogenated hydrocarbons are reacted at a pressure of from 0.2 bar to 3 bar.

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