Composite doped platinum-based catalyst for reducing CO in flue gas, preparation method and application thereof
By using a composite-doped platinum-based catalyst preparation method, the stability and compatibility issues of existing catalysts in reducing CO content in cigarette smoke have been solved, achieving both high-efficiency CO oxidation conversion and compatibility with the cigarette smoking experience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA TOBACCO SHAANXI IND
- Filing Date
- 2026-02-12
- Publication Date
- 2026-06-26
AI Technical Summary
Existing catalysts for reducing CO content in cigarette smoke suffer from problems such as high platinum loading, high cost and poor stability, limited efficiency of non-precious metal catalysts, and the inability of some catalysts to be adapted to low-temperature smoking of cigarettes due to high temperature requirements. Furthermore, the preparation process is complex and has poor compatibility with filter production.
A composite doped platinum-based catalyst is used to form a catalytic structure with high specific surface area and abundant active sites by polymerizing and pyrolyzing H2PtCl6·6H2O, melamine, and glyoxal, and then mixing it with graphene oxide. This structure is added to cigarette filters to achieve the oxidative conversion of CO.
It significantly reduces the CO content in flue gas, is compatible with existing filter production processes, requires no large-scale equipment modifications, and does not affect the vaping experience.
Smart Images
Figure CN122273553A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of cigarette manufacturing technology, and in particular to a composite doped platinum-based catalyst for reducing CO in cigarette smoke, its preparation method, and its application. Background Technology
[0002] Carbon monoxide (CO) is one of the most harmful and representative harmful components in mainstream cigarette smoke, and it is listed in the WHO's list of controlled tobacco products and the controlled lists of harmful tobacco components in many countries. During smoking, the thermal decomposition and incomplete combustion of tobacco components generate a large amount of CO. CO has a much stronger affinity for hemoglobin than oxygen, easily forming carboxyhemoglobin, which hinders the blood's oxygen-carrying function. This leads to damage to hypoxia-sensitive tissues such as the central nervous system and myocardium, causing symptoms such as dizziness and fatigue, and in severe cases, endangering life. With increasing consumer health awareness and stricter industry harm reduction policies, efficiently reducing the CO content in cigarette smoke without affecting the smoking quality has become a core technical challenge that the tobacco industry urgently needs to solve, and it has significant industry value and social significance.
[0003] Existing technologies for reducing CO in cigarette smoke mainly include cigarette material optimization, combustion process control, and smoke after-treatment. Among these, catalytic oxidation has become the mainstream research direction due to its direct efficiency and minimal impact on cigarette quality. Current catalytic technologies include various types such as precious metal (Pt, Pd, Au, etc.) catalysts, transition metal oxide catalysts, and perovskite catalysts. Some technologies achieve CO catalytic conversion by adding the catalyst to the filter or tobacco. However, single precious metal catalysts suffer from high platinum loading and high cost, and the active components are prone to agglomeration and CO poisoning, resulting in poor catalytic stability and low utilization of active sites. Furthermore, although non-precious metal or composite oxide catalysts are cheaper, their catalytic efficiency is limited, with CO reduction rates generally less than 15%, and some carriers easily adsorb aroma components in the smoke, destroying the original taste of cigarettes. At the same time, some catalysts require temperatures above 200°C to have effective catalytic activity, which cannot be adapted to the low-temperature conditions during cigarette filter smoking. On the other hand, catalysts with optimized low-temperature activity have problems such as complex preparation processes and poor compatibility with existing filter production processes.
[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention
[0005] To address the aforementioned issues, this application provides a composite doped platinum-based catalyst for reducing CO in cigarette smoke, its preparation method, and its application. The catalyst prepared by this method exhibits extremely uniform dispersion of metal species and uses very small amounts of metal. The addition of commercially available graphene oxide further enhances its oxidizing properties, effectively reducing the CO content in cigarette smoke.
[0006] To achieve the objectives of this application, the following technical solution is provided: In a first aspect, this application provides a method for preparing a composite-doped platinum-based catalyst for reducing CO in cigarette smoke, comprising: H2PtCl6·6H2O, melamine and glyoxal were mixed in a solvent and heated and stirred to polymerize the precursor. The solvent was then evaporated to obtain the polymerized precursor. The polymer precursor was pyrolyzed to obtain a carbon-doped nitrogen material, which was then ball-milled and sieved before being mixed with graphene oxide to obtain a composite-doped platinum-based catalyst.
[0007] In one possible implementation, the ratio of H2PtCl6·6H2O, melamine, glyoxal, and solvent is 1 mmol:(0.3–0.9) mol:(0.3–0.9) mol:(0.9–1.5) L.
[0008] In one possible implementation, when adding the graphene oxide to the ball-milled and sieved carbon-nitrogen-doped material, the graphene oxide is added at a ratio of 0 wt% to 20 wt%.
[0009] In one possible implementation, the heating and stirring temperature is 70–120°C.
[0010] In one possible implementation, the carbon-nitrogen-doped material has a mesh size of 60-100 after ball milling and sieving.
[0011] In one possible implementation, the pyrolysis temperature is 850–1000°C.
[0012] In one possible implementation, the pyrolysis atmosphere is nitrogen or argon.
[0013] Secondly, this application provides a composite-doped platinum-based catalyst for reducing CO in cigarette smoke, which is prepared by the above-described method for preparing a composite-doped platinum-based catalyst for reducing CO in cigarette smoke.
[0014] Thirdly, this application provides the application of a composite doped platinum-based catalyst for reducing CO in cigarette smoke in the preparation of cigarettes, wherein the above-mentioned composite doped platinum-based catalyst for reducing CO in cigarette smoke is added to the filter element of the cigarette filter.
[0015] In one possible implementation, the amount of the composite doped platinum-based catalyst for reducing CO in cigarette smoke is 5 to 50 mg.
[0016] The technical solution provided in this application may include the following beneficial effects: The composite doped platinum-based catalyst for reducing CO in cigarette smoke, its preparation method, and its application provided in this application can achieve synergistic effects between platinum-based active components, carbon-doped nitrogen materials, and graphene oxide through the polymerization and pyrolysis of H2PtCl6·6H2O, melamine, and glyoxal, as well as their combination with graphene oxide. This results in a catalytic structure with high specific surface area and abundant active sites. Furthermore, it can efficiently catalyze the oxidation and conversion of CO in cigarette smoke under cigarette smoking conditions, significantly reducing the content of harmful CO in cigarette smoke. At the same time, this application method is highly compatible with existing cigarette filter production processes, requiring no large-scale equipment modifications and not affecting the normal smoking experience of cigarettes.
[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description
[0018] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of the invention to explain this application and do not constitute a limitation thereof. Obviously, the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.
[0019] Figure 1 A schematic flowchart illustrating a method for preparing a composite-doped platinum-based catalyst for reducing CO in cigarette smoke, provided in an embodiment of this application; Figure 2 TEM image of a composite doped platinum-based catalyst for reducing CO in cigarette smoke, provided in an embodiment of this application. Detailed Implementation
[0020] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0021] This example embodiment first provides a method for preparing a composite-doped platinum-based catalyst for reducing CO in cigarette smoke, including: Step S100: Mix H2PtCl6·6H2O, melamine and glyoxal in a solvent, heat and stir to polymerize the precursor, and then evaporate the solvent to obtain the polymer precursor; Step S200: The polymer precursor is pyrolyzed to obtain a carbon-doped nitrogen material, which is then ball-milled and sieved before being mixed with graphene oxide to obtain a composite-doped platinum-based catalyst.
[0022] The solvent is an aqueous solvent, the pyrolysis is achieved by a preset temperature and atmosphere, and the graphene oxide can be commercially available graphene oxide.
[0023] In one embodiment, the ratio of H2PtCl6·6H2O, melamine, glyoxal, and solvent is 1 mmol:(0.3–0.9) mol:(0.3–0.9) mol:(0.9–1.5) L.
[0024] It should be noted that this dosage ratio ensures that melamine and glyoxal undergo a full polymerization reaction and that H2PtCl6·6H2O is uniformly dispersed in the polymer, while avoiding insufficient polymerization due to insufficient raw material dosage, and ensuring that each reactant is uniformly dispersed in the system.
[0025] In one embodiment, when adding graphene oxide to the carbon-nitrogen-doped material after ball milling and sieving, the graphene oxide is added at a ratio of 0 wt% to 20 wt%.
[0026] It should be noted that the graphene oxide used is commercially available graphene oxide. Blending with it can achieve synergistic effects with carbon-doped nitrogen materials. However, if the amount used exceeds the above ratio, it will lead to an insufficient number of metal catalytic sites, thereby affecting the final performance of the catalyst.
[0027] In one embodiment, the heating and stirring temperature is 70–120°C.
[0028] It should be noted that this heating and stirring temperature can avoid the problem of polymerization not occurring or the rate being too slow, making it difficult to form a structurally stable polymer precursor. At the same time, it can also avoid the thermal decomposition of some reactants or excessive polymerization that prevents the metal species from being uniformly anchored.
[0029] In one embodiment, the carbon-nitrogen-doped material has a mesh size of 60-100 after ball milling and sieving.
[0030] It should be noted that the particle size corresponding to this mesh range can ensure the uniformity of the material particles, which is convenient for subsequent full mixing and contact with graphene oxide. It will not cause problems such as dust flying and difficulty in operation due to excessively fine particles, or reduce the dispersibility of the material due to excessively coarse particles.
[0031] In one embodiment, the pyrolysis temperature is 850–1000°C, and the pyrolysis atmosphere is nitrogen or argon.
[0032] It should be noted that this temperature range can promote the full carbonization of the polymerization precursor and achieve uniform doping of nitrogen. Using nitrogen or argon as the pyrolysis atmosphere can create an inert environment, prevent the carbon-doped nitrogen material from being oxidized during high-temperature pyrolysis, and ensure the stability of its structure and composition.
[0033] Furthermore, this application provides a composite-doped platinum-based catalyst for reducing CO in cigarette smoke, which is prepared by the above-described method for preparing a composite-doped platinum-based catalyst for reducing CO in cigarette smoke.
[0034] It should be noted that, as Figure 2 As shown, the loading of Pt on the composite doped platinum-based catalyst for reducing CO in cigarette smoke is 0.31 wt%, and the average particle size of the Pt nanoclusters is 0.5~0.6 nm.
[0035] Furthermore, this application also provides the application of a composite doped platinum-based catalyst for reducing CO in cigarette smoke in the preparation of cigarettes, wherein the above-mentioned composite doped platinum-based catalyst for reducing CO in cigarette smoke is added to the filter element of the cigarette filter.
[0036] It should be noted that adding this catalyst to the cigarette filter element takes advantage of the fact that the filter is the necessary passage for the smoke, which allows the smoke to come into full contact with the catalyst, thereby maximizing the catalytic effect. At the same time, this addition method is highly compatible with the existing cigarette filter production process and does not require large-scale modification of existing equipment.
[0037] The amount of the composite doped platinum-based catalyst for reducing CO in cigarette smoke is 5-50 mg.
[0038] It should be noted that this addition range can avoid the problem of insufficient effective active sites of the catalyst, making it difficult to achieve the expected CO reduction effect, while also avoiding excessive filter suction resistance, which would affect the smoking experience of cigarettes.
[0039] The following detailed embodiments illustrate the composite-doped platinum-based catalyst for reducing CO in cigarette smoke according to this application: Example 1: 0.517 g of H2PtCl6·6H2O and 75.7 g of melamine were added to 1.2 L of aqueous solution and stirred. After the metal salt was dissolved, 87.0 mL of glyoxal aqueous solution (40%) was added. The precursor was polymerized and the solvent was evaporated under heating and stirring at 90 °C. After the solvent was completely evaporated, the polymer precursor was obtained. The obtained polymerization precursor was pyrolyzed at 900℃ under a nitrogen atmosphere. The pyrolyzed carbon-doped nitrogen material was ball-milled and passed through an 80-mesh sieve. It was then uniformly mixed with 10 wt% of commercial graphene oxide to obtain a composite doped platinum-based catalyst.
[0040] The catalyst was added to each cigarette filter with 40mg. Standard cigarette filters and cigarettes were prepared sequentially using conventional methods. The CO content in the smoke during the combustion of the prepared cigarettes was analyzed. Cigarettes of the same specification without any catalyst were used as blank control samples. The CO reduction rate was calculated by taking the average value after three parallel tests under the same test conditions. The results are shown in Table 1.
[0041] Table 1
[0042] Example 2: 0.517 g of H2PtCl6·6H2O and 37.8 g of melamine were added to 0.9 L of aqueous solution and stirred. After the metal salt was dissolved, 43.5 mL of glyoxal aqueous solution (40%) was added. The precursor was polymerized and the solvent was evaporated under heating and stirring at 70 °C. After the solvent was completely evaporated, the polymer precursor was obtained. The obtained polymerization precursor was pyrolyzed at 850°C under a nitrogen atmosphere. The pyrolyzed carbon-doped nitrogen material was ball-milled and passed through a 60-mesh sieve. It was then uniformly mixed with 0 wt% commercial graphene oxide to obtain a composite doped platinum-based catalyst.
[0043] The catalyst was added to each cigarette filter with 10mg, and standard cigarette filters and cigarettes were prepared sequentially according to conventional methods. The CO content in the smoke during the combustion of the prepared cigarettes was analyzed. Cigarettes of the same specification without any catalyst were used as blank control samples. The CO reduction rate was calculated by taking the average value after three parallel tests under the same test conditions. The results are shown in Table 2.
[0044] Table 2
[0045] Example 3: 0.517 g of H2PtCl6·6H2O and 113.5 g of melamine were added to 1.5 L of aqueous solution and stirred. After the metal salt was dissolved, 130.5 mL of glyoxal aqueous solution (40%) was added. The precursor was polymerized and the solvent was evaporated under heating and stirring at 120 °C. After the solvent was completely evaporated, the polymer precursor was obtained. The obtained polymerization precursor was pyrolyzed at 1000℃ under a nitrogen atmosphere. The pyrolyzed carbon-doped nitrogen material was ball-milled and passed through a 100-mesh sieve. It was then uniformly mixed with 20wt% commercial graphene oxide to obtain a composite doped platinum-based catalyst.
[0046] Each cigarette filter was supplemented with 50 mg of catalyst. Standard cigarette filters and cigarettes were prepared sequentially using conventional methods. The CO content in the smoke during the combustion of the prepared cigarettes was analyzed. Cigarettes of the same specifications without any catalyst in the filter were used as blank control samples. The samples were tested in parallel three times under the same testing conditions, and the average value was taken to calculate the CO reduction rate. The results are shown in Table 3.
[0047] Table 3
[0048] Example 4: 0.517 g of H2PtCl6·6H2O and 56.8 g of melamine were added to 1.2 L of aqueous solution and stirred. After the metal salt was dissolved, 65.0 mL of glyoxal aqueous solution (40%) was added. The precursor was polymerized and the solvent was evaporated under heating and stirring at 90 °C. After the solvent was completely evaporated, the polymer precursor was obtained. The obtained polymerization precursor was pyrolyzed at 900℃ under a nitrogen atmosphere. The pyrolyzed carbon-doped nitrogen material was ball-milled and passed through an 80-mesh sieve. It was then uniformly mixed with 10 wt% of commercial graphene oxide to obtain a composite doped platinum-based catalyst.
[0049] Each cigarette filter was supplemented with 50 mg of catalyst. Standard cigarette filters and cigarettes were prepared sequentially using conventional methods. The CO content in the smoke during the combustion of the prepared cigarettes was analyzed. Cigarettes of the same specifications without any catalyst in the filter were used as blank control samples. The samples were tested in parallel three times under the same testing conditions, and the average value was taken to calculate the CO reduction rate. The results are shown in Table 4.
[0050]
[0051] Example 5: 0.517 g of H2PtCl6·6H2O and 94.6 g of melamine were added to 1.2 L of aqueous solution and stirred. After the metal salt was dissolved, 109.0 mL of glyoxal aqueous solution (40%) was added. The precursor was polymerized and the solvent was evaporated under heating and stirring at 90 °C. After the solvent was completely evaporated, the polymer precursor was obtained. The obtained polymerization precursor was pyrolyzed at 900℃ under a nitrogen atmosphere. The pyrolyzed carbon-doped nitrogen material was ball-milled and passed through an 80-mesh sieve. It was then uniformly mixed with 10 wt% of commercial graphene oxide to obtain a composite doped platinum-based catalyst.
[0052] Each cigarette filter was supplemented with 50 mg of catalyst. Standard cigarette filters and cigarettes were prepared sequentially using conventional methods. The CO content in the smoke during the combustion of the prepared cigarettes was analyzed. Cigarettes of the same specifications without any catalyst in the filter were used as blank control samples. The samples were tested in parallel three times under the same testing conditions, and the average value was taken to calculate the CO reduction rate. The results are shown in Table 5.
[0053] Table 5
[0054] Example 6: 0.517 g of H2PtCl6·6H2O and 75.7 g of melamine were added to 1.2 L of aqueous solution and stirred. After the metal salt was dissolved, 87.0 mL of glyoxal aqueous solution (40%) was added. The precursor was polymerized and the solvent was evaporated under heating and stirring at 90 °C. After the solvent was completely evaporated, the polymer precursor was obtained. The obtained polymerization precursor was pyrolyzed at 850°C under a nitrogen atmosphere. The pyrolyzed carbon-doped nitrogen material was ball-milled and passed through an 80-mesh sieve. It was then uniformly mixed with 10 wt% of commercial graphene oxide to obtain a composite doped platinum-based catalyst.
[0055] Each cigarette filter was supplemented with 50 mg of catalyst. Standard cigarette filters and cigarettes were prepared sequentially using conventional methods. The CO content in the smoke during the combustion of the prepared cigarettes was analyzed. Cigarettes of the same specifications without any catalyst in the filter were used as blank control samples. The samples were tested in parallel three times under the same testing conditions, and the average value was taken to calculate the CO reduction rate. The results are shown in Table 6.
[0056] Table 6
[0057] Example 7: 0.517 g of H2PtCl6·6H2O and 75.7 g of melamine were added to 1.2 L of aqueous solution and stirred. After the metal salt was dissolved, 87.0 mL of glyoxal aqueous solution (40%) was added. The precursor was polymerized and the solvent was evaporated under heating and stirring at 90 °C. After the solvent was completely evaporated, the polymer precursor was obtained. The obtained polymerization precursor was pyrolyzed at 900℃ under an argon atmosphere. The pyrolyzed carbon-doped nitrogen material was ball-milled and passed through an 80-mesh sieve. It was then uniformly mixed with 10 wt% of commercial graphene oxide to obtain a composite doped platinum-based catalyst.
[0058] The catalyst was added to each cigarette filter at a rate of 40 mg. Standard cigarette filters and cigarettes were prepared sequentially using conventional methods. The CO content in the smoke during the combustion of the prepared cigarettes was analyzed. Cigarettes of the same specification without any catalyst added to the cigarette filters were used as blank control samples. The samples were tested in parallel three times under the same testing conditions, and the average value was taken to calculate the CO reduction rate. The results are shown in Table 7.
[0059] Table 7
[0060] In the description of this specification, references to terms such as "one possible implementation," "further," "exemplary," "specific example," or "optional," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.
[0061] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention filed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not claimed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the appended claims.
Claims
1. A method for preparing a composite-doped platinum-based catalyst for reducing CO in cigarette smoke, characterized in that, include: H2PtCl6·6H2O, melamine and glyoxal were mixed in a solvent and heated and stirred to polymerize the precursor. The solvent was then evaporated to obtain the polymerized precursor. The polymer precursor was pyrolyzed to obtain a carbon-doped nitrogen material, which was then ball-milled and sieved before being mixed with graphene oxide to obtain a composite-doped platinum-based catalyst.
2. The method for preparing a composite-doped platinum-based catalyst for reducing CO in cigarette smoke according to claim 1, characterized in that, The ratio of H2PtCl6·6H2O, melamine, glyoxal, and solvent is 1 mmol:(0.3–0.9) mol:(0.3–0.9) mol:(0.9–1.5) L.
3. The method for preparing the composite-doped platinum-based catalyst for reducing CO in cigarette smoke according to claim 1, characterized in that, When adding the graphene oxide to the carbon-nitrogen-doped material after ball milling and sieving, the graphene oxide is added at a ratio of 0 wt% to 20 wt%.
4. The method for preparing the composite-doped platinum-based catalyst for reducing CO in cigarette smoke according to claim 3, characterized in that, The heating and stirring temperature is 70–120°C.
5. The method for preparing the composite-doped platinum-based catalyst for reducing CO in cigarette smoke according to claim 4, characterized in that, The carbon-nitrogen-doped material has a mesh size of 60-100 after ball milling and sieving.
6. The method for preparing the composite-doped platinum-based catalyst for reducing CO in cigarette smoke according to claim 3, characterized in that, The pyrolysis temperature is 850–1000℃.
7. The method for preparing a composite-doped platinum-based catalyst for reducing CO in cigarette smoke according to claim 1, characterized in that, The pyrolysis atmosphere is nitrogen or argon.
8. A composite-doped platinum-based catalyst for reducing CO in cigarette smoke, characterized in that, It is prepared by the method for preparing composite doped platinum-based catalyst for reducing CO in cigarette smoke as described in any one of claims 1-7.
9. The application of a composite-doped platinum-based catalyst for reducing CO in cigarette smoke in the preparation of cigarettes, characterized in that, The composite doped platinum-based catalyst for reducing CO in cigarette smoke, as described in claim 8, is added to the filter element of the cigarette filter.
10. The application of the composite doped platinum-based catalyst for reducing CO in cigarette smoke according to claim 9 in the preparation of cigarettes, characterized in that, The amount of the composite doped platinum-based catalyst for reducing CO in cigarette smoke is 5-50 mg.