Method for preparing a supported carbon catalyst, supported carbon catalyst and use thereof

Abstract

A method for preparing a supported carbon catalyst, the method includes at least the following steps: contacting a gas containing an organic silicon source with a silicon oxide-based material to obtain a precursor; contacting the precursor with a gas containing an organic carbon source to obtain the supported carbon catalyst. The temperature and energy consumption of the chemical vapor deposition of heteroatom-containing carbon material on silica-based materials can be greatly reduced in this method, and the cost of the catalyst can be effectively reduced.

Claims

1. A method for preparing a supported carbon catalyst, wherein the method comprises: Step (1): contacting a gas containing an organic silicon source with a silicon oxide-based material to obtain a precursor; Step (2): contacting the precursor with a gas containing an organic carbon source to obtain the supported carbon catalyst, wherein the precursor obtained in step (1) contacts with the gas containing the organic carbon source at a contact temperature in a range from 500° C. to 1000° C. for 0.1 hour to 10 hours.

2. The method according to claim 1, wherein the organic silicon source in the step (1) is at least one selected from the group consisting of a compound with a chemical formula shown in formula I and a compound with a chemical formula shown in formula II: ##STR00003## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently selected from the group consisting of hydrogen, a C.sub.1 to C.sub.12 hydrocarbyl group, a C.sub.1 to C.sub.12 substituted hydrocarbyl group, a C.sub.1 to C.sub.5 hydrocarbyloxy group, a C.sub.1 to C.sub.5 alkylacyloxy group, halogen and amino; and at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is a C.sub.1 to C.sub.12 hydrocarbyl group or a C.sub.1 to C.sub.12 substituted hydrocarbyl group; and at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is hydrogen, a C.sub.1 to C.sub.5 hydrocarbyloxy group, a C.sub.1 to C.sub.5 alkylacyloxy, halogen or amino; ##STR00004## wherein A is O or NH; R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 are each independently selected from the group consisting of hydrogen, a C.sub.1 to C.sub.12 hydrocarbyl group, a C.sub.1 to C.sub.12 substituted hydrocarbyl group, a C.sub.1 to C.sub.5 hydrocarbyloxy group, a C.sub.1 to C.sub.5 alkylacyloxy group, halogen or amino; and at least one of R.sub.5, R.sub.6 and R.sub.7 is a C.sub.1 to C.sub.12 hydrocarbyl group or a C.sub.1 to C.sub.12 substituted hydrocarbyl group; and at least one of R.sub.8, R.sub.9 and R.sub.10 is a C.sub.1 to C.sub.12 hydrocarbyl group or a C.sub.1 to C.sub.12 substituted hydrocarbyl group.

3. The method according to claim 2, wherein a substituent is contained in the substituted hydrocarbyl group; the substituent is at least one selected from the group consisting of halogen, amino, epoxyethyl, sulfydryl, cyano, isocyanate group, and ethylenediamine.

4. The method according to claim 1, wherein the organic silicon source in step (1) is least one selected from the group consisting of dichlorodimethylsilane, hexamethyldisiloxane, trimethylchlorosilane, phenyltrichlorosilane and dimethoxydimethylsilane.

5. The method according to claim 1, wherein the gas containing the organic silicon source in step (1) contains or does not contain an inactive gas; the inactive gas is at least one selected from the group consisting of nitrogen, argon gas and helium gas.

6. The method according to claim 1, wherein the silicon oxide-based material in step (1) is porous silicon dioxide.

7. The method according to claim 1, wherein the gas containing the organic silicon source in step (1) contacts with the silicon oxide-based material at a contact temperature in a range from 100° C. to 500° C. for 0.1 hour to 10 hours.

8. The method according to claim 1, wherein the gas containing the organic silicon source in step (1) contacts with the silicon oxide-based material at a contact temperature in a range from 200° C. to 450° C. for 0.2 hour to 4 hours.

9. The method according to claim 1, wherein the mass percentage of the silicon oxide-based material in the precursor is in a range from 80 wt % to 98 wt %.

10. The method according to claim 1, wherein the mass percentage of the silicon oxide-based material in the precursor is in a range from 90 wt % to 97 wt %.

11. The method according to claim 1, wherein the organic carbon source in the step (1) is at least one of a C.sub.1 to C.sub.18 organic compound; the organic compound contains at least one selected from the group consisting of nitrogen, oxygen, boron, phosphorus, and sulfur.

12. The method according to claim 1, wherein the organic carbon source in step (2) is at least one selected from the group consisting of nitrile compounds, pyridine compounds, organic phosphine compounds, organoboron compounds, thiophene compounds, phenol compounds, and alcohol compounds.

13. The method according to claim 1, wherein the gas containing the organic carbon source in step (2) contains an inactive gas; the inactive gas is at least one selected from the group consisting of nitrogen, argon gas and helium gas.

14. The method according to claim 1, wherein the precursor in step (2) contacts with the gas containing the organic carbon source at a contact temperature in a range from 600° C. to 900° C. for 0.1 hour to 4 hours.

15. The method according to claim 1, wherein the mass percentage of the silicon oxide-based material in the supported carbon catalyst is in a range from 60 wt % to 95 wt %.

16. The method according to claim 1, wherein the mass percentage of the silicon oxide-based material in the supported carbon catalyst is in a range from 75 wt % to 93 wt %.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a photograph of sample 1.sup.#.

(2) FIG. 2 is a photograph of sample 2.sup.#.

(3) FIG. 3 is a photograph of sample D-1.sup.#.

DETAILED DESCRIPTION

(4) The method for preparing a supported carbon catalyst comprises the following steps:

(5) (1) depositing an organic silicone source gas on a surface of a porous silicon dioxide as a catalyst carrier by a vapor deposition method;

(6) (2) introducing an organic gas onto the surface of the porous silicon dioxide treated in the step (1) to vapor-deposit the supported carbon on the surface of the porous silicon dioxide.

(7) In the examples, the silica gel pellets with a particle diameter of 2 mm to 4 mm were purchased from Qingdao Ocean Chemical Co., Ltd., and which were colorless and transparent.

(8) Silica gel powder was purchased from Dongying Yiming New Material Co., Ltd., with a particle diameter of 80 mesh to 120 mesh and a color of white;

(9) FNG silica gel was purchased from Qingdao Ocean Chemical Co., Ltd., with a particle diameter of 2 mm to 4 mm and a color of white.

Example 1

(10) The FNG silica gel that washed with hydrochloric acid having a mass concentration of 20% was used as a carrier, the dimethyldichlorosilane was used as an organic silicone source in step (1), and the acetonitrile was used as an organic precursor for vapor-depositing in step (2).

(11) (1) 65 mL of FNG silica gel was put into a quartz tube, the quartz tube was placed in the tube furnace, a nitrogen gas was introduced as a carrier gas and the temperature was raised to 400° C., and then the gas path was switched so that the nitrogen gas carrying the vaporized dichlorodimethylsilane entered into the quartz tube by way of a bubbling device. The vapor deposition process was performed for 2 hours to graft organosilane to obtain a precursor.

(12) In vapor deposition, the flow rate of the nitrogen gas was 100 mL/min; the temperature of the dichlorodimethylsilane bubbler was 25° C.

(13) (2) the gas path was switched so that the nitrogen gas entered into the quartz tube directly not through the bubbling device, and the gas path was switched again after the temperature was raised to 800° C. so that the nitrogen gas carrying vaporized acetonitrile entered into the quartz tube by way of another bubbling device. The chemical vapor deposition process was performed for 2 hours.

(14) In vapor deposition, the flow rate of the nitrogen gas was 100 mL/min; the temperature of the acetonitrile bubbler was 65° C.

(15) The gas path was switched so that the nitrogen gas entered into the quartz tube directly not through another bubbling device, a nitrogen-containing supported carbon catalyst sample was obtained after natural cooling in nitrogen, and was designated as sample 1.sup.#.

(16) The mass ratio of the precursor to FNG silica gel was 1.10:1.

(17) The mass ratio of sample 1.sup.# to FNG silica gel was 1.12:1.

(18) The photograph of sample 1.sup.# is shown in FIG. 1.

(19) As can be seen from FIG. 1, the surface of sample 1.sup.# appears black, indicating that the carbon material is sufficiently loaded onto the carrier.

Example 2

(20) The silica gel powder was used as a carrier, the hexamethyldisiloxane was used as an organic silicon source in the step (1), and the pyridine was used as an organic precursor for vapor-depositing in step (2).

(21) (1) 125 mL of silica gel powder was put into a quartz tube, the quartz tube was placed in the tube furnace, a nitrogen gas was introduced as a carrier gas and the temperature was raised to 400° C., and then the gas path was switched so that the nitrogen gas carrying the vaporized hexamethyldisiloxane entered into the quartz tube by way of a bubbling device. The vapor deposition process was performed for 2 hours to graft organosilane.

(22) In vapor deposition, the flow rate of the nitrogen gas was 200 mL/min; the temperature of the hexamethyldisiloxane bubbler was 30° C.

(23) (2) the gas path was switched so that the nitrogen gas entered into the quartz tube directly not through the bubbling device, and the gas path was switched again after the temperature was raised to 750° C. so that the nitrogen gas carrying vaporized pyridine entered into the quartz tube by way of another bubbling device. The chemical vapor deposition process was performed for 2 hours.

(24) In vapor deposition, the flow rate of the nitrogen gas was 250 mL/min; the temperature of the pyridine bubbler was 90° C.

(25) The gas path was switched so that the nitrogen gas entered into the quartz tube directly not through another bubbling device, a nitrogen-containing supported carbon catalyst sample was obtained after natural cooling in nitrogen, and was designated as sample 2.sup.#.

(26) The mass ratio of the precursor to the silica gel pellets was 1.08:1.

(27) The mass ratio of sample 2.sup.# to the silica gel pellets was 1.17:1.

(28) The photograph of sample 2.sup.# is shown in FIG. 2.

(29) As can be seen from FIG. 2, the surface of sample 2.sup.# appears black, indicating that the carbon material is sufficiently loaded onto the carrier.

Example 3

(30) The silica gel pellets that washed with hydrochloric acid having a mass concentration of 20% were used as a carrier, the trimethylchlorosilane was used as an organic silicone source in step (1), and the triphenylphosphine was used as an organic precursor for vapor-depositing in step (2).

(31) (1) 65 mL of silica gel pellets were put into a quartz tube, the quartz tube was placed in the tube furnace, an argon gas was introduced as a carrier gas and the temperature was raised to 400° C., and then the gas path was switched so that the argon gas carrying the vaporized trimethylchlorosilane entered into the quartz tube by way of a bubbling device. The vapor deposition process was performed for 2 hours to graft organosilane.

(32) In vapor deposition, the flow rate of the argon gas was 100 mL/min; the temperature of the trimethylchlorosilane bubbler was 30° C.

(33) (2) the gas path was switched so that the argon gas entered into the quartz tube directly not through the bubbling device, and the gas path was switched again after the temperature was raised to 800° C. so that the argon gas carrying vaporized triphenylphosphine entered into the quartz tube by way of another bubbling device. The chemical vapor deposition process was performed for 4 hours.

(34) In vapor deposition, the flow rate of the argon gas was 100 mL/min; the temperature of the triphenylphosphine bubbler was 280° C.

(35) The gas path was switched so that the argon gas entered into the quartz tube directly not through another bubbling device, a phosphorus-containing supported carbon catalyst sample was obtained after natural cooling in argon, and was designated as sample 3.sup.#.

(36) The mass ratio of the precursor to the silica gel pellets was 1.10:1.

(37) The mass ratio of sample 3.sup.# to the silica gel pellets was 1.06:1.

(38) The appearance of sample 3.sup.# is similar to that of sample 1.sup.#, and the surface of sample 3.sup.# appears black, indicating that the carbon material is sufficiently loaded onto the carrier.

Example 4

(39) The silica gel pellets that washed with hydrochloric acid having a mass concentration of 20% were used as a carrier, the phenyltrichlorosilane was used as an organic silicone source in step (1), and the triphenylboron was used as an organic precursor for vapor-depositing in step (2).

(40) (1) 65 mL of silica gel pellets were put into a quartz tube, the quartz tube was placed in the tube furnace, a nitrogen gas was introduced as a carrier gas and the temperature was raised to 400° C., and then the gas path was switched so that the nitrogen gas carrying the vaporized phenyltrichlorosilane entered into the quartz tube by way of a bubbling device. The vapor deposition process was performed for 2 hours to graft organosilane.

(41) In vapor deposition, the flow rate of the nitrogen gas was 100 mL/min; the temperature of the phenyltrichlorosilane bubbler was 120° C.

(42) (2) the gas path was switched so that the nitrogen gas entered into the quartz tube directly not through the bubbling device, and the gas path was switched again after the temperature was raised to 750° C. so that the nitrogen gas carrying vaporized triphenylboron entered into the quartz tube by way of another bubbling device. The chemical vapor deposition process was performed for 2 hours.

(43) In vapor deposition, the flow rate of the nitrogen gas was 100 mL/min; the temperature of the triphenylboron bubbler was 280° C.

(44) The gas path was switched so that the nitrogen gas entered into the quartz tube directly not through another bubbling device, a boron-containing supported carbon catalyst sample was obtained after natural cooling in nitrogen, and was designated as sample 4.sup.#.

(45) The mass ratio of the precursor to the silica gel pellets was 1.06:1.

(46) The mass ratio of sample 4.sup.# to the silica gel pellets was 1.07:1.

(47) The appearance of sample 4.sup.# is similar to that of sample 1.sup.#, and the surface of sample 4.sup.# appears black, indicating that the carbon material is sufficiently loaded onto the carrier.

Example 5

(48) The silica gel pellets that washed with hydrochloric acid having a mass concentration of 20% were used as a carrier, the dichlorodimethylsilane was used as an organic silicone source in step (1), and the thiophene was used as an organic precursor for vapor-depositing in step (2).

(49) (1) 65 mL of silica gel pellets were put into a quartz tube, the quartz tube was placed in the tube furnace, a nitrogen gas was introduced as a carrier gas and the temperature was raised to 400° C., and then the gas path was switched so that the nitrogen gas carrying the vaporized dichlorodimethylsilane entered into the quartz tube by way of a bubbling device. The vapor deposition process was performed for 2 hours to graft organosilane.

(50) In vapor deposition, the flow rate of the nitrogen gas was 100 mL/min; the temperature of the dichlorodimethylsilane bubbler was 20° C.

(51) (2) the gas path was switched so that the nitrogen gas entered into the quartz tube directly not through the bubbling device, the temperature was raised to 700° C. and then the thiophene was input into the quartz tube by charging pump. The chemical vapor deposition process was performed for 0.2 hours.

(52) In vapor deposition, the flow rate of the nitrogen was 100 mL/min; the flow rate of thiophene was 0.25 mL/min.

(53) The sulfur-containing supported carbon catalyst sample was obtained after natural cooling in nitrogen, and was designated as sample 5.sup.#.

(54) The mass ratio of the precursor to the silica gel pellets was 1.10:1.

(55) The mass ratio of sample 5.sup.# to the silica gel pellets was 1.06:1.

(56) The appearance of sample 5.sup.# is similar to that of sample 1.sup.#, and the surface of sample 5.sup.# appears black, indicating that the carbon material is sufficiently loaded onto the carrier.

Example 6

(57) The silica gel pellets that washed with hydrochloric acid having a mass concentration of 20% were used as a carrier, the dimethyldimethoxysilane was used as an organic silicone source in step (1), and the phenol was used as an organic precursor for vapor-depositing in step (2).

(58) (1) 65 mL of silica gel pellets were put into a quartz tube, the quartz tube was placed in the tube furnace, a nitrogen gas was introduced as a carrier gas and the temperature was raised to 400° C., and then the gas path was switched so that the nitrogen gas carrying the vaporized dichlorodimethylsilane entered into the quartz tube by way of a bubbling device. The vapor deposition process was performed for 2 hours to graft organosilane.

(59) In vapor deposition, the flow rate of the nitrogen gas was 100 mL/min; the temperature of the dimethyldimethoxysilane bubbler was 20° C.

(60) (2) the gas path was switched so that the nitrogen gas entered into the quartz tube directly not through the bubbling device, and the gas path was switched again after the temperature was raised to 800° C. so that the nitrogen gas carrying vaporized phenol entered into the quartz tube by way of another bubbling device. The chemical vapor deposition process was performed for 0.2 hours.

(61) In vapor deposition, the flow rate of the nitrogen gas was 100 mL/min; the temperature of the phenol bubbler was 130° C.

(62) The gas path was switched so that the nitrogen gas entered into the quartz tube directly not through another bubbling device, an oxygen-containing supported carbon catalyst sample was obtained after natural cooling in nitrogen, and was designated as sample 6.sup.#.

(63) The mass ratio of the precursor to the silica gel pellets was 1.08:1.

(64) The mass ratio of sample 6.sup.# to the silica gel pellets was 1.05:1.

(65) The appearance of sample 6.sup.# is similar to that of sample 1.sup.#, and the surface of sample 6.sup.# appears black, indicating that the carbon material is sufficiently loaded onto the carrier.

Example 7

Performance Test of Catalyst

(66) The samples 1.sup..Math. to 6.sup.# were used as catalysts for testing the catalytic performance in the the cracking reaction of 1,2-dichloroethane for the preparation of chloroethylene. The specific steps and conditions were as follows:

(67) 1,2-dichloroethane liquid was preheated and vaporized in the evaporator, and then passed to a fixed bed reactor loaded with the catalyst by a constant flow pump. The reactor temperature was 250° C., the gaseous hourly space velocity (GHSV) of 1,2-dichloroethane was 133 h.sup.−1.

(68) The reaction results show that the conversion rates of 1,2-dichloroethane are each higher than 15%, and the selectivities to chloroethylene are each more than 99% using samples 1.sup.# to 6.sup.# as catalysts in the cracking reaction of 1,2-dichloroethane for the preparation of chloroethylene.

(69) The conversion rate of 1,2-dichloroethane is 40% and the selectivity to chloroethylene is more than 99% using sample 1.sup.# as a typical example.

Comparative Example 1

(70) Other steps and conditions were the same as that in example 1 except that the vapor phase deposition process for grafting organosilane was not included, specifically:

(71) (1) 65 mL of FNG silica gel was put into a quartz tube, the quartz tube was placed in the tube furnace, a nitrogen gas was introduced as a carrier gas and the temperature was raised to 800° C., and then the gas path was switched so that the nitrogen gas carrying the vaporized acetonitrile entered into the quartz tube by way of an acetonitrile bubbler. The vapor deposition process was performed for 2 hours.

(72) The gas path was switched so that the nitrogen gas entered into the quartz tube directly not through the bubbling device, a sample designated as sample D-1.sup.# was obtained after natural cooling in nitrogen.

(73) A sample photograph of the sample of D-1.sup.# is shown in FIG. 3.

(74) As can be seen from FIG. 3, the surface of sample D-1.sup.# appears very light gray, indicating that the amount of carbon material supported on the surface of the FNG silica gel is extremely small.

(75) If the silicone source is not grafted in advance, the nitrogen-containing organic materials can hardly be loaded on the silica gel carrier.

(76) The above are only a few embodiments of the present application, and are not intended to limit the present application in any form. Although the present application is disclosed by the preferred embodiments as above, they are however not used to limit the present application. A slight change or modification utilizing the technical content disclosed above made by the person skilled in art, without departing from the technical solution of the present application, is equivalent to the equivalent embodiment, and falls within the scope of the technical solution.