Thermochemical processes using heterogenous catalysts for the fabrication of carbon nanocrystalline materials.

Abstract

Invention details;

Description

[0001] TITLE OF THE INVENTION

[0002] A THERMOCHEMICAL PROCESS USING HETEROGENEOUS CATALYSTS FOR THE PRODUCTION OF NANOCRYSTALLINE CARBON MATERIALS

[0003] FIELD OF INVENTION

[0004] The present disclosure relates to the production of a carbon nanomaterial, including a nanocrystalline carbon with a ID, 2D, or 3D structure and / or a nanocrystalline diamond and / or an amorphous carbon and / or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or transition metal, and / or a mixture thereof, particularly when said production of carbon nanomaterials involves heterogeneous catalytic thermochemical reduction.

[0005] BACKGROUND OF THE INVENTION

[0006] A carbon nanomaterial, including a nanocrystalline carbon with a ID, 2D, or 3D structure and / or a nanocrystalline diamond and / or an amorphous carbon and / or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or transition metal, and / or a mixture thereof, is being consumed at an accelerated rate despite its unavailability in nature. Such consumption trend arises in various fields of applications, especially in the electronics industry, owing to the carbon nanomaterial’s excellent properties such as superior strength and electrical properties.

[0007] The current state of the art suggests that catalytic thermochemical conversion of an oxygenic carbon source is a promising production route for carbon nanomaterial. Its straightforward process and ease of upscaling are key factors of such recognition.

[0008] Nevertheless, catalytic thermochemical processes in the arts have a major downside: a high reaction temperature. This requirement leads to high energy consumption, CO2 emission, as well as production costs. This problem is conventionally solved by a metal catalyst which reduces the reaction energy, though even the energy reduced thus is still considered high.

[0009] International patent publication No. WO 2013 / 158155 Al discloses a process of catalytic thermochemical reduction of carbon dioxide. Notwithstanding the use of a gaseous reducing agent and a steel catalyst, said process requires a temperature within the range of approximately 450 - 800 °C.

[0010] Similarly, the US patent publication No. US 2005 / 0079118 Al discloses a catalytic thermochemical process for transforming an oxygenic organic carbon source into single wall carbon nanotubes using a metal catalyst. This process still requires an operating temperature of 500 - 1,500 °C, and thus requires high energy.

[0011] Accordingly, it is necessary to provide a new method for producing carbon nanomaterials which addresses the problem of energy consumption while maintaining the advantages of thermochemical reduction as known in the arts.

[0012] SUMMARY OF THE INVENTION

[0013] An object of the present invention is to provide a new process for industrially producing a carbon nanomaterial. The inventor has found that embodiments according to the concept of the present invention enable the production of such products at a significantly less energy-intensive condition, as well as satisfactory yield and reaction time.

[0014] In the first aspect, the present invention provides a new process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and / or a nanocrystalline diamond and / or an amorphous carbon and / or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and / or a mixture thereof. Said process comprises thermochemically reducing of an oxygenic carbon source at an atmospheric pressure and an onset temperature within the range of 25 - 100 °C. Said thermochemical reduction is carried out in presence of: (a) an ionic solution comprising a solvent and an ionic salt, and (b) metallic particles acting as a heterogeneous catalyst, said metallic particles comprising one or more of the following: a post-transition element, a transition element, an oxide, and an alloy thereof.

[0015] Said range of the onset temperature, which simplifies the production, is an effect that distinguishes a process in accordance with the present invention from the currently available ones. The metal -carbon nanomaterial composite product yield per a single run of an embodiment, which depends on the type of the metal catalyst, the oxygenic carbon source and the reaction time, is approximately 10 - 100 g-L^ h"1. Such yield is conducive to the scale-up to a mass production scale.

[0016] Preferably, the metallic particles comprise one or more of the following: the posttransition element and the transition element. Also preferably, the post-transition element is bismuth (Bi), and the transition element is silver (Ag). Also preferably, the size of said metallic particles is within the range of 10 - 1,000 nm.

[0017] Preferably, the metallic particles are exposed to the ambient air or oxygen-containing atmosphere at 30 - 125 °C for 30 minutes to 24 hours before the reaction.

[0018] In an embodiment, said oxygenic carbon source is dissolved in the solvent. In such case, it is preferable that said oxygenic carbon source is dissolved in the solvent at the concentration within the range of 0. 1 - 10 M.

[0019] In another embodiment, said solvent is a polar solvent. In such case, it is preferable that said polar solvent is water. Also in such case, it is preferable that said oxygenic carbon source is water-soluble. More preferably, said oxygenic carbon source is (i) an oxygenic organic compound or (ii) a carbonate salt, a bicarbonate salt or a mixture thereof.

[0020] In an embodiment where the oxygenic carbon source is an oxygenic organic compound, it is even more preferable that such oxygenic organic compound is a carboxylic acid, an alcohol, a ketone, an aldehyde, or a carbamate.

[0021] In an embodiment where the oxygenic organic compound is a carboxylic acid, it is most preferably acetic acid. In an embodiment where the oxygenic organic compound is an alcohol, it is most preferably ethanol. In an embodiment where the oxygenic organic compound is a ketone, it is most preferably acetone. In an embodiment where the oxygenic organic compound is an aldehyde, it is most preferably acetaldehyde. In an embodiment where the oxygenic organic compound is a carbamate, said carbamate is preferably prepared by saturating a primary amine aqueous solution with CO2; and in such embodiment, it is most preferred that the primary amine is mono ethanolamine and / or that the concentration of the primary amine aqueous solution is within the range of 0. 1 - 10 M.

[0022] In an embodiment where the oxygenic carbon source is or involves a carbonate salt, the carbonate salt is most preferably Na2CC>3. In an embodiment where the oxygenic carbon source is or involves a bicarbonate salt, the bicarbonate salt is most preferably NH4HCO3.

[0023] The carbonate salt is preferably prepared by saturating an aqueous solution of a strong base with CO2. In such embodiment, most preferably the strong base is KOH; also most preferably, the strong base’s concentration in the aqueous solution is within the range of 0.1 - 10 M.

[0024] The bicarbonate salt is preferably prepared by saturating an aqueous solution of a tertiary amine, or by saturating an ammonia aqueous solution, with CO2. More preferably, the tertiary amine is dimethylethanolamine (DMAE); also more preferably, the tertiary amine’s concentration in the aqueous solution is within the range of 0.1 - 10 M.

[0025] Also more preferably, the ammonia’s concentration in the aqueous solution is within the range of 0.1 - 10 M.

[0026] Preferably, the ionic salt comprises a cation selected from ammonium cation, imidazolium cation, and a mixture thereof. Preferably, said ammonium cation is ammonium cation (NH4+) and choline cation. Preferably, said imidazolium cation is l-butyl-3- methylimidazolium ([bmim]).

[0027] Preferably, the anion of said ionic salt is selected from the group comprising tetrafluoroborate (BEp), hexafluorophosphate (PFr,“). halides (O’, Br, F", I"), hexafluoroantimonate (SbFr>“). sulfate (SOr2-). and nitrate (NO ).

[0028] The most preferable ionic salts are: l-butyl-3- methylimidazolium tetrafluoroborate ([bmim][BF4]) or ammonium sulfate ((NFL^SCh) or choline chloride.

[0029] Preferably, the concentration of said ionic salt in the ionic solution is within the range of 0.1 - 10 M.

[0030] Preferably, H2O2 or Fe (II) ions are added to the ionic solution.

[0031] In the second aspect, the present invention provides a process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and / or a nanocrystalline diamond and / or an amorphous carbon and / or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and / or a mixture thereof. Said process comprises steps of: (i) thermochemically reducing an oxygenic carbon source in presence of (a) an ionic solution, and (b) metallic particles suspended in said ionic solution and acting as a heterogeneous catalyst; and (ii) stirring said ionic solution. Said ionic solution comprises a mixture of (a) 1- butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), ammonium sulfate ((NH4)2SO4) or choline chloride, and (b) water. Said thermochemically reducing the oxygenic carbon source occurs at an atmospheric pressure and an onset temperature within the range of 25 - 100 °C.

[0032] The above step of (ii), stirring the ionic solution, may be carried out before or during the thermochemical reduction and may be carried out continuously or intermittently. Preferably, the ionic solution is stirred continuously during the thermochemical reduction.

[0033] Accordingly, the present disclosure provides examples to illustrate the conditions of such processes and the characteristic properties of such products. The preferred embodiments will be described in detail later on. BRIEF DESCRIPTION OF DRAWINGS

[0034] Fig. 1 shows a schematic diagram of a thermochemical reactor for thermochemically reducing an oxygenic carbon source in accordance with a preferred embodiment (not to scale).

[0035] Fig. 2A shows a Raman spectrum exhibiting merged peaks of a product of Example 1.

[0036] Fig. 2B shows a matching of d-spacing, as obtained from Selected Area Electron Diffraction (SAED), of the product of Example 1.

[0037] Fig. 2C shows a first Transmission Electron Microscopy (TEM) image of the product of Example 1.

[0038] Fig. 2D shows a second Transmission Electron Microscopy (TEM) image of the product of Example 1.

[0039] Fig. 2E shows Energy Dispersive X-ray (EDX) peaks of the product of Example 1.

[0040] Fig. 3A shows a Raman spectrum exhibiting merged peaks of a product of Example 2.

[0041] Fig. 3B shows a matching of d-spacing, as obtained from Selected Area Electron Diffraction (SAED), of the product of Example 2.

[0042] Fig. 3C shows a first Transmission Electron Microscopy (TEM) image of the product of Example 2.

[0043] Fig. 3D shows a second Transmission Electron Microscopy (TEM) image of the product of Example 2.

[0044] Fig. 3E shows Energy Dispersive X-ray (EDX) peaks of the product of Example 2.

[0045] Fig. 4A shows a Raman spectrum exhibiting merged peaks of a product of Example 3.

[0046] Fig. 4B shows a matching of d-spacing, as obtained from Selected Area Electron Diffraction (SAED), of the product of Example 3.

[0047] Fig. 4C shows a first Transmission Electron Microscopy (TEM) image of the product of Example 3.

[0048] Fig. 4D shows a second Transmission Electron Microscopy (TEM) image of the product of Example 3.

[0049] Fig. 4E shows Energy Dispersive X-ray (EDX) peaks of the product of Example 3.

[0050] Fig. 5 shows a Raman spectrum exhibiting merged peaks of a product of Example 4.

[0051] Fig. 6 shows a Raman spectrum exhibiting merged peaks of a product of Example 5.

[0052] Fig. 7 shows a Raman spectrum exhibiting merged peaks of a product of Example 6.

[0053] Fig. 8 shows a Raman spectrum exhibiting merged peaks of a product of Example 7.

[0054] Fig. 9 shows a Raman spectrum exhibiting merged peaks of a product of Example 8. Fig. 10 shows a Raman spectrum exhibiting merged peaks of a product of Example 9.

[0055] Fig. 11 shows a Raman spectrum exhibiting merged peaks of a product of Example 10.

[0056] Fig. 12 shows a Raman spectrum exhibiting merged peaks of a product of Example 11.

[0057] Fig. 13 shows a Raman spectrum exhibiting merged peaks of a product of Example 12.

[0058] Fig. 14 shows a Raman spectrum exhibiting merged peaks of a product of Example 13.

[0059] Fig. 15 shows a Raman spectrum exhibiting merged peaks of a product of Example 14.

[0060] Fig. 16 shows a Raman spectrum exhibiting merged peaks of a product of Example 15.

[0061] DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0062] It is to be understood that the following detailed description will be directed to embodiments, provided as examples for illustrating the concept of the present invention only. The present invention is in fact not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of this invention will be limited only by the appended claims.

[0063] The detailed description of the invention is divided into various sections only for the reader’s convenience and disclosure found in any section may be combined with that in another section.

[0064] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0065] It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

[0066] The term “about” when used before a numerical designation, e.g., dimensions, time, amount, and such other, including a range, indicates approximations which may vary by ( + ) or ( - ) 10 %, 5 % or 1 %, or any sub-range or sub-value there between.

[0067] “Comprising” or “comprises” is intended to mean that the compositions and processes include the recited elements, but not excluding others. “Consisting essentially of’ when used to define compositions and methods, shall mean excluding other elements of any essential significance to the combination for the stated purpose. Thus, a process or product consisting essentially of the elements as defined herein would not exclude other materials or steps that do not materially affect the basic and novel characteristic(s) of the claimed invention. “Consisting of’ shall mean excluding more than trace elements of other ingredients and substantial steps. Embodiments defined by each of these transition terms are within the scope of this invention.

[0068] “Oxygenic carbon source” is intended to mean a mono-molecular compound or an ionic compound containing both carbon and oxygen atoms.

[0069] “Oxygenic organic compound” is intended to mean a mono-molecular organic compound having an oxygen atom.

[0070] Thermochemical reactor

[0071] Fig. 1 shows a schematic diagram of a thermochemical reactor in which a process for producing a carbon nanomaterial is conducted in accordance with a preferred embodiment. The thermochemical reactor (10) comprises a receptacle (100), a heating element (200), a stirrer (300), and a vent (400). The receptacle (100) contains an ionic solution (110) in which metallic particles (120) are present and act as a heterogeneous catalyst. The ionic solution (110) is a mixture of an ionic salt and a solvent in which an oxygenic carbon source is dissolved. The heating element (200), the source of thermal energy, is preferably connected to the lower part or the bottom of the receptacle (100) and configured to heat the ionic solution (110). The stirrer (300) is preferably disposed so as to immerse in the ionic solution (110) and configured to disperse the metallic particles (120) in the ionic solution (110). In this preferred embodiment, the stirrer (300) takes the form of a propeller having a shaft (310), an end of which is connected to multiple blades (320), and another end of which, to a motor (330). The shaft (310) is disposed substantially vertically so that the blades (320) are effectively immersed in the ionic solution (110) and the motor (330) is located away from the ionic solution (110). The vent (400), through which the gaseous byproducts leave the receptacle (100), is preferably located at the top of the receptacle (100).

[0072] Oxygenic carbon source

[0073] In the present invention, the carbon source is an oxygenic carbon source. Preferably, a water-soluble oxygenic carbon source is used. Preferably, the oxygenic carbon source is a carbonate salt or a bicarbonate salt. Preferred carbonate and bicarbonate salts include: Na2CO and NH4HCO3. The carbonate salt is prepared by saturating an aqueous solution of a strong base with CO2. The bicarbonate salt is prepared by saturating (i) an ammonia aqueous solution or (ii) an aqueous solution of a tertiary amine, with CO2. More preferably, the concentration of the strong base, ammonia, or the tertiary amine, in their respective aqueous solution is within the range of 0.1 - 10 M. Also preferably, the oxygenic carbon source is an oxygenic organic compound. Preferred oxygenic organic compounds include: an alcohol, carboxylic acid, ketone, aldehyde, and carbamate. Preferably, the carbamate is prepared by saturating primary amine aqueous solution with CO2. More preferably, the primary amine is mono ethanolamine and / or the concentration of the primary amine aqueous solution is within the range 0.1 - 10 M. In addition, the oxygenic carbon source may be supplied to the ionic solution in any desired form, for example, in the solid, liquid, gaseous, or solvated form, depending on the phase stability at the operating temperature and pressure. Preferably, the oxygenic carbon source is dissolved in the ionic solution (i.e., supplied in the solvated form).

[0074] Pressure

[0075] A process according to the concept of the present invention may be carried out in various conditions which may be adjusted according to the circumstantial requirements. The applicable pressure is within the range of about 1 to about 20 atm.

[0076] The pressure in accordance with the preferred embodiment is an ambient pressure. The ambient pressure refers to a common or usual condition surrounding any person in a room. An ambient pressure for operating the process is preferably 1 atm. Because a process in accordance with the preferred embodiment allows the catalytic thermochemical reduction to occur effectively at such ambient pressure, it obviates the need to pressurize, depressurize, vacuumize or control the pressure at any part of the thermochemical reactor (10) and thus substantially simplifies the production.

[0077] Onset temperature

[0078] Generally, the onset temperature of the thermochemical reactor (10) is at least of the thermal energy sufficient to initiate the catalytic thermochemical reduction of the oxygenic carbon source. Preferably, the onset temperature of the ionic solution (110) is substantially constant during the catalytic thermochemical reduction.

[0079] The onset temperature of the thermochemical reactor (10) depends on the carbon source and the metallic particles being selected. In an embodiment, the thermochemical reactor (10) comprises a heating element (200) to provide the onset temperature, which is preferably within a range of about 25 - 100 °C.

[0080] Preferably, the heating element (200) is adapted to monitor and control the onset temperature. In the following Examples, the catalytic thermochemical reduction occurred in an autoclave which is capable of both monitoring and regulating the onset temperature. The autoclave is commonly used as an industry-scale thermochemical reactor, which is applicable to the concept of the present invention.

[0081] Ionic solution According to the concept of the present invention, the ionic solution (110) comprises a solvent and an ionic salt. Preferably, the solvent is a polar solvent, and more preferably is water.

[0082] According to the concept of the present invention, all known ionic salts may be part of the mixture that forms the ionic solution (110). Preferably, the ionic salts in an embodiment are compounds represented by Formula (I):

[0083] [A]n+[Y]n- - (I) wherein: n is 1 or 2;

[0084] [Y]n‘ is selected from the group comprising tetrafluoroborate (| BF4|“). hexafluorophosphate ([ PFr, ]’), halides (C1‘, Br, F", I"), hexafluoroantimonate ([ SbFr, ]’), sulfate ([SO ’]), and nitrate ([NCh]’);

[0085] [A]+is selected from —

[0086] (a) the group comprising ammonium cations represented by Formula (II):

[0087] R1, R2, R3, and R4being selected from hydrogen atom, Cl-C6-alkyl, Cl-C6-alkoxy, Cl- C6-aminoalkyl, Cl-C6-hydroxylalkyl, C5-C12-aryl, and C5-C12-aryl-Cl-C6-alkyl groups; and

[0088] (b) the group comprising imidazolium cations represented by Formula (III): R, R1, and R2being selected from Cl-C6-alkyl, Cl-C6-alkoxy, Cl-C6-aminoalkyl, C5- C12-aryl, and C5-C12-aryl-Cl-C6-alkyl groups.

[0089] The preferred combination of the ionic salt, the oxygenic carbon source, and water is as follows: (a) the ionic salt being a mixture of l-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), ammonium sulfate ((NH^SCh) or choline chloride, (b) an oxygenic carbon source, and (c) water.

[0090] In some embodiments, the ionic salt also functions as a stabilizer of nanoparticles / carbon nanomaterial formed at the metallic particles (120) during the catalytic thermochemical reduction of the oxygenic carbon source in the thermochemical reactor (10). Preferably, the ionic salt is selected from ([bmim][BF4]), (NFL^SCh, and choline chloride.

[0091] Metallic particles

[0092] According to an embodiment, the metallic particles (120) act as a heterogeneous catalyst for the catalytic thermochemical reduction.

[0093] Preferably, the metallic particles (120) comprise one or more of the following: the posttransition element and the transition element. More preferably, the post-transition element is Bi and the transition element is Ag.

[0094] Preferably, the size of the metallic particles is within the range of 10 - 1,000 nm.

[0095] As a pre-treatment step, the metallic particles are exposed to the ambient air or oxygencontaining atmosphere at 30 - 125 °C for 30 minutes to 24 hours in order to create a thin oxide layer before the start of thermochemical reduction.

[0096] Reaction time

[0097] According to an embodiment, the catalytic thermochemical reduction occurs in the thermochemical reactor (10) as a batch operation. The crystal structure and crystal size of the resulting product depends on the nature of metallic particles (120), the carbon source used, the energy supplied, and the reaction time, among others. Prolonging the reaction time results in a larger crystallite size being formed.

[0098] According to the embodiments, the reaction time for each batch of production can be ranged from about 5 minutes to 300 minutes. Preferably, the reaction time for each batch of production is about 15 minutes to 75 minutes.

[0099] Nanocrystalline carbon with a ID, 2D, or 3D structure and / or a nanocrystalline diamond and / or an amorphous carbon and / or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and / or a mixture thereof In a preferred embodiment, the process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and / or a nanocrystalline diamond and / or an amorphous carbon and / or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and / or mixture thereof in the thermochemical reactor (10) is a batch operation.

[0100] The nanocrystalline carbon with the ID, 2D, or 3D structure and / or the nanocrystalline diamond and / or the amorphous carbon and / or the metal-carbon nanomaterial composite, said composite containing a post-transition metal or transition metal, and / or the mixture thereof is formed at the metallic particles (120).

[0101] The carbon product obtained from a process in accordance with a preferred embodiment comprises a graphite and / or a graphene and / or a graphitic carbon and / or the nanocrystalline diamond and / or the amorphous carbon, and / or the metal-carbon nanomaterial composite, said composite containing the post-transition metal or the transition metal, and / or the mixture thereof.

[0102] In some embodiments, the carbon product being produced is further separated from the metallic particles (120) by a known separation process. Preferably, said separation process is a mechanical removal process, such as mechanical abrasion, or ultrasonication.

[0103] After being separated from the metallic particles (120), the carbon product may contain metallic material residues, which can be further removed from the carbon product by means of a conventional chemical removal process, preferably acid leaching. Preferably, said acid leaching involves the use of nitric acid (HNO3), hydrochloric acid (HC1), or a mixture thereof.

[0104] In some embodiments, the separation process of the carbon product from the metallic particles (120) comprises the following steps:

[0105] (1) mechanically removing the solid product from the metallic particles (120)

[0106] (2) placing the solid product that was removed by step (1) in a microcentrifuge tube

[0107] (3) slowly dropping a mixture of nitric acid and hydrochloric acid into the microcentrifuge tube to perform acid leaching. Preferably, the mixture of nitric acid and hydrochloric acid is in a molar ratio of 1:3 in 0.3 ml of the solution

[0108] (4) shaking the solution before ultrasonicating the solution for approximately 5 minutes

[0109] (5) centrifuging the solution to separate the solid product from the solution

[0110] (6) collecting the solid product and neutralizing the solid product with deionized water (DI water). Preferably, the neutralization is conducted three times.

[0111] The abovementioned process results in a nanocrystalline carbon with a ID, 2D, or 3D structure and / or a nanocrystalline diamond and / or an amorphous carbon product and / or a metal- carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and / or a mixture thereof, which is a mixture having various carbon structures. Said structures are inclusive of, and selectable from: an amorphous carbon, a graphite, a graphene, a nanocrystalline diamond, and a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal.

[0112] Examples of embodiments

[0113] In the fifteen Examples carried out for the preferred embodiment, the following applies: Catalytic thermochemical reductions took place in a batch thermochemical reactor (10). The thermochemical reactor (10) further contained the ionic solution (110), the onset temperature of which was generated and measured by the heating element (200). The ionic solution (110) was dispersed with the metallic particles (120) and stirred by the stirrer (300) at the agitation rate of 10 - 1,000 rpm. The reaction was carried out under a pressure of about 1 atm. After the reaction time, the carbon nanomaterial product was formed at the metallic particles (120), which was then removed from the ionic solution (110) and dried.

[0114] Moreover, the metallic particles (120) were exposed to the ambient air or oxygencontaining atmosphere at 30 - 125 °C for 30 minutes to 24 hours before being used in the thermochemical reduction.

[0115] Some oxygenic carbon sources were prepared by saturating the ionic solution (110) with carbon dioxide gas (CO2) at ambient conditions. More particularly, where the oxygenic carbon source was a carbonate salt, the ionic solution (110) contained KOH (a strong base); where the oxygenic carbon source was a bicarbonate salt, the ionic solution (110) contained ammonia or dimethylethanolamine (a tertiary amine); where the oxygenic carbon source was a carbamate, the ionic solution (110) contained mono ethanolamine (a primary amine). The flow rate of CO 2 per volume of the ionic solution (110) was within the range of 0.04 - 40 cm3CO2 per cm3ionic solution per minute. The CO2 purging time was within 1-1,000 minutes.

[0116] Table 1 in the next sheet shows the particulars of Examples 1-15. Description of the product obtained from each Example shall follow Table 1.

[0117] Example 1 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. Fig. 2A shows the Raman spectrum of the product of Example 1. Moreover, the Selected Area Electron Diffraction (SAED) analysis revealed the lattice spacing of said product as 0.206, 0.179, 0.134, 0.119, and 0.103 nanometer (nm) which, as shown in Fig. 2B, matched the lattice spacing references of n- diamond, i-Carbon and hexagonal diamond. Next, images from the Transmission Electron Microscopy (TEM) are shown in Figs. 2C and 2D. Finally, the peaks from Energy Dispersive X-ray (EDX) analysis, shown in Fig. 2E, revealed the following atomic percentages of said product: 91.34 % carbon; 1.65 % oxygen; 1.86 % copper; 0.5 % silver; 0.33 % iodine; and 4.31 % mercury. All the foregoing results confirmed that the product of Example 1 comprised nanocrystalline diamond comprising n-diamond, hexagonal diamond, i-Carbon, graphitic carbon, and amorphous carbon structures.

[0118] Example 2 produced a metal-carbon composite product in the form of nanocrystalline carbon with a 2D structure. Fig. 3A shows the Raman spectrum of the product of Example 2. Moreover, the Selected Area Electron Diffraction (SAED) analysis revealed the lattice spacing of said product as 0.211, 0.201, 0.123, 0.116, and 0.106 nanometer (nm) which, as shown in Fig. 3B, matched the lattice spacing references of graphite. Next, images from the Transmission Electron Microscopy (TEM) are shown in Figs. 3C and 3D. Finally, the peaks from Energy Dispersive X-ray (EDX) analysis, shown in Fig. 3E, revealed the following atomic percentage of said product: 100 % carbon. All the foregoing results confirmed that the product of Example 2 comprised graphene, graphitic carbon, and amorphous carbon structures.

[0119] Example 3 produced a metal -carbon composite product in the form of metallic Bi / Bi oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. Fig. 4A shows the Raman spectrum of the product of Example 3. Moreover, the Selected Area Electron Diffraction (SAED) analysis revealed the lattice spacing of said product as 0.337, 0. 177, and 0. 145 nanometer (nm) which, as shown in Fig. 4B, matched the lattice spacing references of graphite. Next, images from the Transmission Electron Microscopy (TEM) are shown in Figs. 4C and 4D. Finally, the peaks from Energy Dispersive X-ray (EDX) analysis, shown in Fig. 4E, revealed the following atomic percentages of said product: 53.34 % carbon; 27.1 % oxygen; 3.44 % fluorine; 15.19 % tin; and 0.93 % bismuth. All the foregoing results confirmed that the product of Example 3 comprised graphitic carbon, and amorphous carbon structures. Example 4 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 5, as observed from the shown Raman spectrum, the carbon product obtained from Example 4 comprised graphitic carbon, and amorphous carbon structures.

[0120] Example 5 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 6, as observed from the shown Raman spectrum, the carbon product obtained from Example 5 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

[0121] Example 6 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 7, as observed from the shown Raman spectrum, the carbon product obtained from Example 6 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

[0122] Example 7 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 8, as observed from the shown Raman spectrum, the carbon product obtained from Example 7 comprised graphitic carbon, and amorphous carbon structures.

[0123] Example 8 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 9, as observed from the shown Raman spectrum, the carbon product obtained from Example 8 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

[0124] Example 9 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 10, as observed from the shown Raman spectrum, the carbon product obtained from Example 9 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

[0125] Example 10 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 11, as observed from the shown Raman spectrum, the carbon product obtained from Example 10 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

[0126] Example 11 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 12 as observed from the shown Raman spectrum, the carbon product obtained from Example 11 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures. Example 12 produced a metal -carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 13, as observed from the shown Raman spectrum, the carbon product obtained from Example 12 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

[0127] Example 13 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 14, as observed from the shown Raman spectrum, the carbon product obtained from Example 13 comprised graphitic carbon, and amorphous carbon structures.

[0128] Example 14 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 15, as observed from the shown Raman spectrum, the carbon product obtained from Example 14 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

[0129] Example 15 produced a metal-carbon composite product in the form of metallic Ag / Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 16, as observed from the shown Raman spectrum, the carbon product obtained from Example 15 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

[0130] List of Drawing References

[0131] 10 thermochemical reactor

[0132] 100 receptacle

[0133] 110 ionic solution

[0134] 120 metallic particle

[0135] 200 heating element

[0136] 300 stirrer

[0137] 310 shaft

[0138] 320 blade

[0139] 330 motor

[0140] 400 vent

Claims

DEPCT6903 / 09 / 25681. A process for the production of one-dimensional, two-dimensional, or three-dimensional nanocrystalline carbon and / or nanocrystalline diamond and / or amorphous carbon and / or metal-carbon nanomaterial composites, such composites containing post-transition metals or transition metals, and / or mixtures of these, by thermochemical reduction of a carbon source with oxygen at atmospheric pressure and an initial temperature within the range of 25-100°C. The phenomenon of (a) an ionic solution consisting of a solvent and an ionic salt, and (b) a heterogenous metal particle acting as a catalyst, such metal particle consisting of one or more of the following: a post-transition element, a transition element, an oxide, and an alloy of these; 2. A process under claim 1 in which the metal particle consists of one or more of the following: a post-transition element and a transition element; 3. A process under claim 1 in which the post-transition element is Bi and the transition element is Ag; 4.

1. The process according to claim 1, where the size of the metal particles is within the range of 10-1,000 nanometers.

5. The process according to claim 1, where the carbon-oxygenated source is dissolved in a solvent.

6. The process according to claim 5, where the carbon-oxygenated source is dissolved in a solvent at a concentration within the range of 0.1-10 molar.

7. The process according to claim 1, where the solvent is a polar solvent.

8. The process according to claim 7, where the polar solvent is water.

9. The process according to claim 1, where the carbon-oxygenated source is soluble in water.

10. The process according to claim 9, where the carbon-oxygenated source is an organic compound containing oxygen.

11. The process according to claim 10, where the organic compound containing oxygen is a carboxylic acid.

12. The process according to claim 11, where the organic compound containing oxygen is acetic acid.

13. The process according to claim 10, where the organic compound containing oxygen is an alcohol.

14. The process according to claim 13, where the organic compound containing oxygen is ethanol. 15.

16. The process according to claim 15, where the organic compound containing oxygen is a ketone.

17. The process according to claim 10, where the organic compound containing oxygen is an aldehyde.

18. The process according to claim 17, where the organic compound containing oxygen is an acetaldehyde.

19. The process according to claim 10, where the organic compound containing oxygen is a carbamate.

20. The process according to claim 19, where carbamates are prepared by causing the substance to... Dissolving aqueous solution of a primary amine saturated with CO2:

21. Process according to claim 20 where the primary amine is monoethanolamine.

22. Process according to claim 20 where the concentration of the aqueous solution of the primary amine is within the range of 0.1-10 molar.

23. Process according to claim 9 where the carbon-oxygen source is a carbonate salt, bicarbonate salt, or a mixture of these.

24. Process according to claim 23 where the carbonate salt is Na2CO3.

25. Process according to claim 23 where the bicarbonate salt is NH4HCO3. 26.

27. The process according to claim 23, in which carbonate salts are prepared by saturating an aqueous solution of a strong base with CO2.

28. The process according to claim 26, in which the strong base is KOH.

29. The process according to claim 26, in which the concentration of the strong base in the aqueous solution is within the range of 0.1-10 molar.

30. The process according to claim 23, in which bicarbonate salts are prepared by saturating an aqueous solution of a tertiary amine with CO2.

31. The process...

31. The process according to claim 29 where the concentration of tertiary amines in the aqueous solution is within the range of 0.1-10⁻⁶ molar.

32. The process according to claim 23 where bicarbonate salts are prepared by saturating an aqueous solution of ammonia with CO2.

33. The process according to claim 32 where the concentration of an aqueous solution of ammonia is within the range of 0.1-10⁻⁶ molar. 34.The process according to claim 1 where ionic salts are compounds represented by the formula (I)[A]n+,[Y]n-----------(I) where n is 1 or 2;[Y]- is chosen from the group which includes tetrafluoroborates ([BF4]-), hexafluorophosphates ([PF6]-), halides (Cl-,Br-,F-,I-), hexafluoroantimonates ([SbF6]-), sulfates ([SO4]2-) and nitrates ([NO3]-);[A]+ is chosen from -(a) the group which includes ammonium cations represented by the formula (II):(chemical formula)--------(II)R1,R2,R3, andR4 are chosen from hydrogen atoms. (a) the group consisting of imidazoleum cations represented by the formula (III): (chemical formula)----------(III)R,R1,andR2 are selected from the groups C1-C6-alkyl,C1-C6-alkoxy,C1-C6-aminoalkyl,C5-C12-aryl,andC5-C12-aryl-C1-C6-alkyl; and (b) the group consisting of imidazoleum cations represented by the formula (III):(chemical formula)----------(III)R,R1,andR2 are selected from the groups C1-C6-alkyl,C1-C6-alkoxy,C1-C6-aminoalkyl,C5-C12-aryl,andC5-C12-aryl-C1-C6-alkyl.

35. The process according to claim 34 in which an ionic solution contains ionic salts at concentrations within the range of 0.1-10 molar.36.The process according to claim 34 in which such ionic salt is 1-butyl-3-methylimidazoleum tetrafluoroborate ([bmim][BF4]) or ammonium sulfate ((NH4)2SO4) or choline chloride.

37. The process according to claim 1 in which H2O2 or Fe(II) ions are added to an ionic solution.38.The process for the production of one-dimensional, two-dimensional, or three-dimensional crystalline carbon nanomaterials and / or crystalline diamond nanomaterials and / or amorphous carbon and / or metal-carbon nanomaterials composites, such composites containing post-transition metals or transition metals, and / or mixtures of these, such a process which comprises the steps of: thermochemical reduction of a carbon source with oxygen in the presence of (a) an ionic solution (110), and (b) metal particles (120) suspended in the solution. Such ionic solution (110) is used as a heterogenous catalyst; and the stirring of such ionic solution (110), in which such ionic solution (110) is composed of a mixture of (a) 1-butyl-3-methylimidazoleum tetrafluoroborate ([bmim][BF4]), ammonium sulfate ((NH4)2SO4) or choline chloride, and (b) water, and in which thermochemical reduction of such oxygen-containing carbon source occurs at atmospheric pressure and an initial temperature within the range of 25–100°C;.

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