A nano-magnesium hydride-attapulgite composite fuel additive and its preparation method

Abstract

This invention relates to the field of fuel additive technology, specifically to a nano-magnesium hydride-attapulgite composite fuel additive and its preparation method. The additive consists of nano-magnesium hydride, a modified attapulgite carrier, and a cerium-based combustion-supporting catalyst, with a mass ratio of 1:(5-20):(0.01-0.1). The modified attapulgite carrier is a surface-grafted graphene-coated composite carrier material. This application achieves anchoring by isolating nano-magnesium hydride particles through a physical barrier network of graphene sheets and by overcoming the strong chemical interaction between the grafted functional groups and nano-magnesium hydride, thus solving the core problems of unstable dispersion, easy agglomeration and deactivation, and insufficient carrier compatibility and anchoring ability. Under the high-temperature environment of the combustion chamber, the highly active hydrogen species released by the decomposition of nano-magnesium hydride can hydrogenate and crack fuel macromolecules and soot precursors, accelerating the combustion chain reaction. The cerium-based compounds provide continuous active oxygen for deep oxidation of soot through their oxygen storage and release function.

Description

Technical Field

[0001] This invention relates to the field of fuel additive technology, specifically to a nano-hydrogenated magnesium-attapulgite composite fuel additive and its preparation method. Background Technology

[0002] With increasingly stringent environmental regulations worldwide, internal combustion engines, especially diesel engines, face immense pressure to reduce emissions of pollutants such as particulate matter and nitrogen oxides. Simultaneously, improving fuel economy and tapping into energy utilization potential are core requirements for the industry's sustainable development. Against this backdrop, developing efficient and clean fuel additives to achieve energy conservation and emission reduction by improving fuel physicochemical properties and combustion processes without altering engine hardware has become a highly valuable research direction.

[0003] In existing technologies, there are many types of fuel additives, mainly including catalytic, surface-active, and cleaning types. Among them, the introduction of nanomaterials with hydrogen storage or catalytic functions has been a research hotspot in recent years. Magnesium hydride, as a lightweight, high-capacity solid hydrogen storage material, has attracted much attention for its application prospects. Theoretically, using nano-sized magnesium hydride as a fuel additive component can decompose upon heating in the engine combustion chamber, releasing highly active hydrogen free radicals, producing a "micro-explosion" effect to promote secondary fuel atomization. At the same time, the addition of hydrogen can broaden the fuel's combustibility limit, increase the combustion rate, and promote the hydrogenation conversion of soot precursors, thereby potentially improving combustion efficiency and reducing soot and unburned hydrocarbon emissions simultaneously.

[0004] However, directly applying nano-magnesium hydride to fuel systems faces serious challenges: First, nanoparticles have high specific surface energy, making them prone to agglomeration and sedimentation in fuel media due to van der Waals forces, leading to a sharp decline in their dispersion stability and effectiveness; second, exposed nano-magnesium hydride is extremely sensitive to oxygen and moisture, and is prone to oxidation or hydrolysis during storage and addition, resulting in deactivation, which not only reduces efficiency but may also introduce instability; third, simple physical mixing makes it difficult for nano-magnesium hydride to achieve sufficient and effective contact and interaction with fuel and soot particles during combustion.

[0005] To overcome the problems of nanoparticle aggregation and deactivation, researchers often employ a support-support strategy. Attapulgite, a natural one-dimensional nanofiber silicate clay mineral, possesses a unique layered chain-like pore structure, a large specific surface area, and high surface activity, making it an ideal catalyst support and adsorbent. Existing technologies have reported the use of attapulgite-supported metal oxide catalysts for catalytic cracking or combustion enhancement. However, traditional attapulgite supports have strong hydrophilicity, poor compatibility with hydrophobic fuels, and limited surface functional groups, resulting in insufficient anchoring ability for active components such as nano-magnesium hydride. The supported composite material is still prone to phase separation or leaching of active components in the fuel.

[0006] On the other hand, single-component additives often have limited functionality. Cerium-based compounds (such as nano-cerium oxide and organic cerium salts) are recognized as highly efficient combustion catalysts. Their unique oxygen vacancy characteristics enable a reversible redox cycle during combustion, continuously providing active oxygen and promoting the low-temperature oxidation of soot particles. The key to improving additive performance lies in effectively integrating hydrogen storage materials with highly efficient combustion catalysts and ensuring their stable dispersion in fuel oil to achieve a synergistic effect of "hydrogen synergistic catalysis."

[0007] Furthermore, in the modification of carrier materials, graphene is widely used for reinforcing composite materials due to its ultra-high specific surface area, excellent chemical stability, and electrical and thermal conductivity. By combining graphene with attapulgite to construct a three-dimensional conductive network and enhanced mechanical structure, it is expected to further improve the load-bearing capacity and stability of the carrier. However, how to achieve uniform coating and firm bonding of graphene on the attapulgite surface, and further perform surface functionalization modification on the composite carrier to enhance its compatibility with hydrophobic fuels and its chemical bonding ability with active components, remains a challenge that has not yet been well resolved in the current technology.

[0008] In summary, there is an urgent need to develop a novel composite fuel additive that can organically combine the hydrogen storage and release properties of nano-magnesium hydride, the catalytic combustion-enhancing properties of cerium-based compounds, and the stable loading and dispersion properties of the attapulgite-graphene composite carrier through innovative carrier design and surface engineering. This would effectively solve the problems of poor dispersion stability, easy deactivation, and limited functionality of nano-active components in fuel, ultimately achieving the goal of significantly improving fuel combustion and reducing carbon emissions at extremely low addition levels. Summary of the Invention

[0009] This application provides a nano-magnesium hydride-attapulgite composite fuel additive and its preparation method, in order to solve the problems of unstable dispersion of active components, easy deactivation, single function, and insufficient carrier compatibility and anchoring ability in the prior art.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention provides a nano-hydride magnesium-attapulgite composite fuel additive, such as... Figure 1 As shown, the additive is composed of nano-magnesium hydride, modified attapulgite carrier, and cerium-based combustion catalyst, with a mass ratio of 1:(5-20):(0.01-0.1); wherein, the modified attapulgite carrier is a surface-grafted graphene-coated composite carrier material; and the cerium-based combustion catalyst is nano-cerium oxide or cerium naphthenate.

[0011] It is understandable that the embodiments of this application, through the synergistic modification of graphene coating and surface grafting, not only solve the problem of long-term dispersion stability of nano-active components in non-polar fuels and eliminate agglomeration and sedimentation, but more importantly, construct an ideal micro-interface environment for subsequent synergistic catalytic reactions.

[0012] Secondly, the nano-magnesium hydride and cerium-based combustion catalyst supported on this carrier do not work independently, but rather trigger a "hydrogen-oxygen synergistic catalysis" mechanism during combustion through a close spatial proximity effect. The nano-magnesium hydride, as a highly efficient hydrogen source, releases active hydrogen species that function both as precursors for hydrogenating and cracking soot and as initiators of the combustion chain reaction. Simultaneously, the cerium-based catalyst provides highly active oxygen species through its unique reversible storage and release of oxygen vacancies. The two combine in situ at the carrier interface, generating highly oxidizing hydroxyl radicals, achieving low-temperature, deep, and efficient catalytic oxidation of soot particles. Its oxidation efficiency far exceeds the simple sum of the individual effects of each component.

[0013] Furthermore, the "micro-explosion" effect generated by the thermal decomposition of uniformly dispersed nano-magnesium hydride within fuel droplets further promotes secondary atomization and homogeneous mixing of the fuel, thereby improving combustion efficiency from a physical perspective. This physical improvement process and the chemical catalytic process mutually promote each other in time and space, forming a virtuous cycle.

[0014] Furthermore, the composite carrier material is prepared by the following method:

[0015] (a) Graphene oxide, attapulgite and kaolin are ultrasonically dispersed in an aqueous phase at a dry basis mass ratio of (0.5-5):(60-90):(5-30) to form a composite slurry;

[0016] (b) Add a reducing agent to the composite slurry, wherein the amount of the reducing agent added is 1-10 times the dry basis mass of the graphene oxide, and carry out a hydrothermal reaction to reduce the graphene oxide and interweave it with the attapulgite and kaolin sheets to obtain a graphene-coated composite carrier precursor.

[0017] (c) The precursor and pyromellitic chloride are subjected to a surface grafting reaction in an organic phase, wherein the mass ratio of pyromellitic chloride to the precursor is (1-10):100, and the modified attapulgite is obtained after the reaction.

[0018] Specifically, step (a) achieves nanoscale uniform mixing of the three components, graphene oxide, attapulgite, and kaolin, in the aqueous phase through ultrasonic dispersion, forming a composite slurry with controllable structure, which is a prerequisite for constructing a uniform composite structure.

[0019] Step (b) is the core construction step. Under hydrothermal conditions, graphene oxide is reduced in situ to graphene, which then physically interweaves and chemically bonds with attapulgite fibers and kaolin sheets, forming a three-dimensional composite precursor with a mineral framework as support and graphene as a coating reinforcement layer. This step not only endows the carrier with excellent mechanical strength and electrical / thermal conductivity, but the resulting graphene network also serves as a physical barrier layer to prevent the subsequent aggregation of active components.

[0020] Step (c) introduces strongly polar functional groups such as carboxyl groups onto the surface of the support precursor through a surface grafting reaction of trimesoyl chloride in the organic phase. This chemical modification fundamentally changes the properties of the support surface, transforming it from hydrophilic to hydrophobic and oleophilic, greatly improving its compatibility with fuel oil. More importantly, these functional groups act as strong chemical anchoring sites, forming robust chemical interactions with the surfaces of active components such as nano-magnesium hydride, achieving a strong molecular-level loading and completely solving the problem of easy leaching and detachment of active components in supported additives.

[0021] Furthermore, the reducing agent is ascorbic acid.

[0022] It is understood that the ascorbic acid in this embodiment is non-toxic and environmentally friendly, avoiding the safety risks and environmental pressures associated with highly toxic substances in production, storage, and wastewater treatment. This aligns with the trend of green chemistry and significantly improves the industrial applicability and safety of the process. Ascorbic acid has a moderate reduction potential, enabling uniform, mild, and controllable reduction of graphene oxide under hydrothermal conditions (120-180℃). This process helps form reduced graphene oxide (rGO) sheets with fewer defects and a more complete structure, allowing for more uniform and robust physical-chemical composites with attapulgite and kaolin, thereby constructing a structurally stable three-dimensional carrier framework. Furthermore, ascorbic acid molecules themselves contain multiple hydroxyl groups. During the reduction of graphene oxide, some of its degradation products or the acid itself may be adsorbed or slightly modified onto the graphene or mineral surface in some form. This may help improve the hydrophilicity / dispersion transition of the composite material, providing a more suitable interfacial environment for subsequent organic phase grafting steps, indirectly promoting the uniformity and efficiency of the trimesoyl chloride grafting reaction.

[0023] Furthermore, the hydrothermal reaction temperature is 120-180℃, and the reaction time is 6-24 hours.

[0024] Furthermore, the surface grafting reaction is carried out under the catalysis of an organic base, wherein the organic base is triethylamine, and the molar ratio of triethylamine to trimesoyl chloride is (1.0-2.5):1; the reaction temperature is 70-80℃, and the reaction time is 2-3 hours.

[0025] It is understood that in the grafting modification process of trimesoyl chloride and hydroxyl groups on the support surface in this application embodiment, triethylamine is selected as the organic base. This base not only efficiently catalyzes the esterification / amidation reaction to accelerate the grafting process, but also immediately neutralizes the reaction byproduct hydrogen chloride (HCl), effectively preventing the acid etching damage of attapulgite, kaolin, and other support mineral skeletons by HCl, ensuring the structural integrity of the support and eliminating undesirable side reactions caused by the acidic environment. Simultaneously, the molar ratio of triethylamine to trimesoyl chloride is strictly controlled to be (1.0-2.5). ):1, which ensures that the acyl chloride group is fully activated and the reaction is complete, while preventing competitive side reactions such as acyl chloride hydrolysis caused by excessive alkali. It precisely controls the grafting density of functional groups on the carrier surface to achieve the best anchoring ability and fuel compatibility. In addition, the reaction temperature of 70-80℃ and the mild reaction conditions of 2-3 hours ensure reaction efficiency while avoiding the thermal decomposition of ester / amide bonds, functional group loss and excessive cross-linking of trimesoyl chloride itself caused by high temperature and long time. This ensures that the introduced carboxyl group and other functional groups are structurally stable and functionally effective.

[0026] Furthermore, the organic phase is an anhydrous organic solvent, wherein the anhydrous organic solvent is selected from one or more of N,N-dimethylformamide, toluene, and dichloromethane.

[0027] Furthermore, the nano-magnesium hydride is prepared by mechanical grinding hydrogenation or liquid phase chemical method, wherein the particle size of the nano-magnesium hydride is 20 nanometers-200 nanometers.

[0028] It should be noted that this application requires the preparation of nano-magnesium hydride under an argon atmosphere in a glove box.

[0029] This application provides a method for preparing a nano-magnesium hydride-attapulgite composite fuel additive, comprising the following steps:

[0030] S1. Preparation of modified attapulgite;

[0031] S2. The composite carrier obtained in S1, nano-magnesium hydride and cerium-based combustion catalyst are mixed in a certain mass ratio and then subjected to mechanochemical ball milling under an inert atmosphere to obtain the composite fuel additive.

[0032] This application provides a fuel composition comprising a base fuel and a nano-magnesium hydride composite fuel additive as described above, wherein the amount of the additive is 10-500 ppm by mass of the fuel.

[0033] This application provides an application of a fuel composition in reducing soot emissions from diesel engines.

[0034] Specifically, by mixing the nano-magnesium hydride-attapulgite composite additive (core component ratio 1:(5-20):(0.01-0.1)) at 300-500 r / min for 15-20 minutes at a ratio of 0.05%-0.5% by mass of the base fuel (China VI 0# diesel), and allowing it to stand to confirm that there is no stratification or sedimentation, the additive can be directly added to the diesel engine fuel tank. Without modifying the engine hardware or adjusting the parameters, carbon emissions can be reduced by more than 44%, and CO and HC emissions and fuel consumption can be reduced simultaneously. It is suitable for the actual working conditions of diesel engines and is easy to use.

[0035] The beneficial effects achieved by using the present invention described above are as follows:

[0036] 1. This invention prepares an attapulgite carrier with dual modification through graphene coating and surface grafting. The uniformly coated graphene sheets on its surface form a physical barrier network, effectively isolating the nano-magnesium hydride particles and preventing their agglomeration due to direct contact with van der Waals forces. The polar functional groups such as carboxyl groups introduced through grafting onto the surface of trimesoyl chloride can interact strongly with the surface of the nano-magnesium hydride, achieving anchoring of the active components. This design firmly and uniformly fixes the originally incompatible nano-active components on the carrier, enabling them to achieve excellent dispersion stability in non-polar fuels. This synergistic effect of physical barrier and chemical anchoring fundamentally overcomes the bottleneck of nanomaterial application in oil products.

[0037] 2. Simultaneously, hydrogen storage materials (nano-magnesium hydride) are integrated with highly efficient combustion catalysts (cerium-based compounds) through a functional carrier. Under the high-temperature environment of the combustion chamber, nano-magnesium hydride first releases highly active atomic hydrogen and hydrogen gas. These active hydrogen species have two key roles: attacking and hydrogenating fuel macromolecules and soot precursors, breaking them down into smaller molecules, thus reducing soot formation at the source; atomic hydrogen is a strong chain initiator, which can significantly accelerate the combustion chain reaction; at the same time, nano-cerium oxide on the carrier exerts its unique oxygen storage and release function, with its abundant oxygen vacancies storing active oxygen under fuel-rich conditions and releasing it in subsequent combustion stages to ensure deep oxidation of soot particles. The active hydrogen released by magnesium hydride and the active oxygen provided by the cerium-based catalyst form a highly active "H•-O" atmosphere on and around the support surface, generating strong oxidizing species such as hydroxyl radicals. Their oxidation potential is much higher than that of ordinary oxygen. The active hydrogen released by magnesium hydride combines in situ with the active oxygen provided by the cerium-based catalyst to generate even stronger oxidizing hydroxyl radicals, thus achieving a doubling of catalytic oxidation efficiency. This allows stubborn soot to be efficiently oxidized into CO2 at relatively low temperatures.

[0038] 3. In this invention, uniformly dispersed nano-magnesium hydride particles inside fuel droplets rapidly decompose upon heating, releasing hydrogen and generating a "micro-explosion" effect. This causes secondary breakup of the fuel droplets, significantly increasing the mixing area between fuel and air and improving atomization quality. This not only promotes complete combustion but also lowers the maximum combustion temperature, helping to reduce the formation of thermal nitrogen oxides. The physical modification effect and the chemical catalytic effect work synergistically in space and time, jointly constructing an efficient pathway from fuel atomization and mixing to complete combustion and pollutant elimination.

[0039] 4. The preparation method provided by this invention organically integrates mature mechanical grinding hydrogenation, hydrothermal synthesis, and surface grafting chemistry, with a clear process flow and controllable parameters. The final mechanochemical composite step is carried out under an inert atmosphere, effectively protecting the activity of nano-magnesium hydride. The entire process is easy to scale up and has the potential for large-scale production.

[0040] This solves the problems of unstable dispersion of active components, easy inactivation, single function, and insufficient carrier compatibility and anchoring ability in existing technologies. Attached Figure Description

[0041] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0042] Figure 1 This is a schematic diagram of the structure of the nano-hydride magnesium-attapulgite composite fuel additive provided in the embodiments of the present invention;

[0043] Figure 2 This is a microscopic schematic diagram of the nano-hydride magnesium-attapulgite composite fuel additive provided in Example 2 of the present invention. Detailed Implementation

[0044] The technical solution of the present invention is illustrated below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or defining the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0045] To better understand the above technical solutions, exemplary embodiments of the present invention are described in more detail below. While exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0046] The following description, with reference to the accompanying drawings, illustrates an embodiment of this application of a nano-magnesium hydride-attapulgite composite fuel additive and its preparation method. Addressing the problem of unstable dispersion of active components mentioned in the background art, this application provides a nano-magnesium hydride-attapulgite composite fuel additive. In this method, a graphene-coated and trimesoyl chloride-grafted attapulgite carrier is prepared. The physical barrier network of graphene sheets isolates the nano-magnesium hydride particles, and the strong chemical interaction between the grafted functional groups and the nano-magnesium hydride achieves anchoring. This synergistically solves the core problems of unstable dispersion, easy agglomeration and deactivation of nano-active components in non-polar fuels, as well as insufficient carrier compatibility and anchoring ability. Simultaneously, relying on this functional carrier, a hydrogen storage material (nano-magnesium hydride) is organically integrated with a highly efficient combustion catalyst (cerium-based compound). Under the high-temperature environment of the combustion chamber, the highly active hydrogen species released by the decomposition of nano-magnesium hydride can both hydrogenate and crack fuel macromolecules. In addition to accelerating the combustion chain reaction with soot precursors, its "micro-explosion" effect can also improve fuel atomization and reduce the maximum combustion temperature to reduce nitrogen oxide generation. Cerium-based compounds provide continuous active oxygen for deep oxidation of soot through oxygen storage and release functions. The "H・-O" highly active atmosphere formed by the two generates strong oxidizing hydroxyl radicals, achieving efficient low-temperature oxidation of soot. Physical improvement and chemical catalytic effects work synergistically in time and space to construct an efficient combustion path throughout the entire process. In addition, this invention adopts a preparation process that integrates mechanical grinding hydrogenation, hydrothermal synthesis and surface grafting chemistry. The process is clear, the parameters are controllable, and the active components are protected under an inert atmosphere, making it easy to scale up. Ultimately, it comprehensively overcomes the problems of single function of active components and poor carrier adaptability in existing technologies, achieving the dual goals of improving combustion efficiency and reducing pollutant emissions.

[0047] The present invention will be further described in conjunction with the following embodiments.

[0048] Example 1

[0049] This invention provides a nano-magnesium hydride-attapulgite composite fuel additive, such as... Figure 1 As shown, the additive consists of nano-magnesium hydride, modified attapulgite carrier, and cerium-based combustion catalyst, with a mass ratio of 1:5:0.01. The modified attapulgite carrier is a surface-grafted graphene-coated composite carrier material, and the cerium-based combustion catalyst is nano-cerium oxide or cerium naphthenate.

[0050] The composite carrier material is prepared by the following method:

[0051] (a) Graphene oxide, attapulgite and kaolin were ultrasonically dispersed in an aqueous phase at a dry basis mass ratio of 0.5:60:5 to form a composite slurry;

[0052] (b) Add a reducing agent to the composite slurry. The amount of reducing agent added is 1 times the dry basis mass of graphene oxide. Perform a hydrothermal reaction to reduce the graphene oxide and interweave it with attapulgite and kaolin sheets to obtain a graphene-coated composite carrier precursor.

[0053] (c) The precursor and pyromellitic chloride are subjected to a surface grafting reaction in an organic phase, wherein the mass ratio of pyromellitic chloride to the precursor is 1:100, and modified attapulgite is obtained after the reaction.

[0054] The reducing agent is ascorbic acid.

[0055] The hydrothermal reaction temperature is 120-180℃, and the reaction time is 6-24 hours.

[0056] The surface grafting reaction was carried out under the catalysis of an organic base, which was triethylamine, with a molar ratio of 1:1 to pyromellitic acid chloride; the reaction temperature was 70-80℃, and the reaction time was 2-3 hours.

[0057] The organic phase is an anhydrous organic solvent, which is selected from one or more of N,N-dimethylformamide, toluene, and dichloromethane.

[0058] Among them, the nano-magnesium hydride is prepared by mechanical grinding hydrogenation or liquid phase chemical method, and the particle size of the nano-magnesium hydride is 20 nanometers-200 nanometers.

[0059] This application provides a method for preparing a nano-magnesium hydride-attapulgite composite fuel additive, comprising the following steps:

[0060] S1. Preparation of modified attapulgite;

[0061] S2. The composite carrier obtained in S1, nano-magnesium hydride and cerium-based combustion catalyst are mixed in a certain mass ratio and then subjected to mechanochemical ball milling under an inert atmosphere to obtain a composite fuel additive.

[0062] This invention provides a fuel composition comprising a base fuel and a nano-magnesium hydride composite fuel additive, wherein the amount of the additive is 10-500 ppm by mass of the fuel.

[0063] This invention provides an application of a fuel composition in reducing carbon emissions from diesel engines.

[0064] Example 2

[0065] This invention provides a nano-magnesium hydride-attapulgite composite fuel additive, such as... Figure 1 As shown, the additive consists of nano-magnesium hydride, modified attapulgite carrier, and cerium-based combustion catalyst, with a mass ratio of 1:10:0.05. Among them, the modified attapulgite carrier is a surface-grafted graphene-coated composite carrier material; the cerium-based combustion catalyst is nano-cerium oxide or cerium naphthenate.

[0066] The composite carrier material is prepared by the following method:

[0067] (a) Graphene oxide, attapulgite and kaolin were ultrasonically dispersed in an aqueous phase at a dry basis mass ratio of 2.5:75:18 to form a composite slurry;

[0068] (b) Add a reducing agent to the composite slurry. The amount of reducing agent added is 5 times the dry basis mass of graphene oxide. Perform a hydrothermal reaction to reduce the graphene oxide and interweave it with attapulgite and kaolin sheets to obtain a graphene-coated composite carrier precursor.

[0069] (c) The precursor and pyromellitic chloride are subjected to a surface grafting reaction in an organic phase, wherein the mass ratio of pyromellitic chloride to precursor is 5:100, and modified attapulgite is obtained after the reaction.

[0070] The reducing agent is ascorbic acid.

[0071] The hydrothermal reaction temperature is 120-180℃, and the reaction time is 6-24 hours.

[0072] The surface grafting reaction was carried out under the catalysis of an organic base, which was triethylamine, and the molar ratio of triethylamine to pyromellitic chloride was 1.8:1; the reaction temperature was 70-80℃, and the reaction time was 2-3 hours.

[0073] The organic phase is an anhydrous organic solvent, which is selected from one or more of N,N-dimethylformamide, toluene, and dichloromethane.

[0074] Among them, the nano-magnesium hydride is prepared by mechanical grinding hydrogenation or liquid phase chemical method, and the particle size of the nano-magnesium hydride is 20 nanometers-200 nanometers.

[0075] This application provides a method for preparing a nano-magnesium hydride-attapulgite composite fuel additive, comprising the following steps:

[0076] S1. Preparation of modified attapulgite;

[0077] S2. The composite carrier obtained in S1, nano-magnesium hydride and cerium-based combustion catalyst are mixed in a certain mass ratio and then subjected to mechanochemical ball milling under an inert atmosphere to obtain a composite fuel additive.

[0078] This invention provides a fuel composition comprising a base fuel and a nano-magnesium hydride composite fuel additive, wherein the amount of the additive is 10-500 ppm by mass of the fuel.

[0079] This invention provides an application of a fuel composition in reducing carbon emissions from diesel engines.

[0080] Example 3

[0081] This invention provides a nano-magnesium hydride-attapulgite composite fuel additive, such as... Figure 1 As shown, the additive consists of nano-magnesium hydride, modified attapulgite carrier, and cerium-based combustion catalyst, with a mass ratio of 1:20:0.1. Among them, the modified attapulgite carrier is a surface-grafted graphene-coated composite carrier material; the cerium-based combustion catalyst is nano-cerium oxide or cerium naphthenate.

[0082] The composite carrier material is prepared by the following method:

[0083] (a) Graphene oxide, attapulgite and kaolin were ultrasonically dispersed in an aqueous phase at a dry weight ratio of 5:90:30 to form a composite slurry.

[0084] (b) Add a reducing agent to the composite slurry. The amount of reducing agent added is 10 times the dry basis mass of graphene oxide. A hydrothermal reaction is carried out to reduce the graphene oxide and interweave it with attapulgite and kaolin sheets to obtain a graphene-coated composite carrier precursor.

[0085] (c) The precursor and pyromellitic chloride are subjected to a surface grafting reaction in an organic phase, wherein the mass ratio of pyromellitic chloride to the precursor is 1:10, and modified attapulgite is obtained after the reaction.

[0086] The reducing agent is ascorbic acid.

[0087] The hydrothermal reaction temperature is 120-180℃, and the reaction time is 6-24 hours.

[0088] The surface grafting reaction was carried out under the catalysis of an organic base, which was triethylamine, with a molar ratio of 2.5:1 to trimesoyl chloride; the reaction temperature was 70-80℃, and the reaction time was 2-3 hours.

[0089] The organic phase is an anhydrous organic solvent, which is selected from one or more of N,N-dimethylformamide, toluene, and dichloromethane.

[0090] Among them, the nano-magnesium hydride is prepared by mechanical grinding hydrogenation or liquid phase chemical method, and the particle size of the nano-magnesium hydride is 20 nanometers-200 nanometers.

[0091] This application provides a method for preparing a nano-magnesium hydride-attapulgite composite fuel additive, comprising the following steps:

[0092] S1. Preparation of modified attapulgite;

[0093] S2. The composite carrier obtained in S1, nano-magnesium hydride and cerium-based combustion catalyst are mixed in a certain mass ratio and then subjected to mechanochemical ball milling under an inert atmosphere to obtain a composite fuel additive.

[0094] This invention provides a fuel composition comprising a base fuel and a nano-magnesium hydride composite fuel additive, wherein the amount of the additive is 10-500 ppm by mass of the fuel.

[0095] This invention provides an application of a fuel composition in reducing carbon emissions from diesel engines.

[0096] Comparative Example 1

[0097] This invention provides a nano-magnesium hydride-attapulgite composite fuel additive, such as... Figure 1 As shown, the additive consists of nano-magnesium hydride, modified attapulgite carrier, and cerium-based combustion catalyst, with a mass ratio of 1:5:0.01; wherein, the cerium-based combustion catalyst is nano-cerium oxide or cerium naphthenate.

[0098] The modified attapulgite carrier was prepared by the following method: Natural attapulgite was activated by stirring in a 10% hydrochloric acid solution at 80°C for 2 hours, washed with water until neutral, dried, and then ground. The activated attapulgite was then mixed with an anhydrous ethanol solution containing 2% (by weight) of KH550 silane coupling agent, refluxed at 70°C for 4 hours, filtered, washed, and dried to obtain the modified attapulgite.

[0099] Among them, the nano-magnesium hydride is prepared by mechanical grinding hydrogenation or liquid phase chemical method, and the particle size of the nano-magnesium hydride is 20 nanometers-200 nanometers.

[0100] This application provides a method for preparing a nano-magnesium hydride-attapulgite composite fuel additive, comprising the following steps:

[0101] S1. Preparation of modified attapulgite;

[0102] S2. The modified attapulgite, nano-magnesium hydride and cerium-based combustion catalyst obtained in S1 are mixed in a certain mass ratio and then subjected to mechanochemical ball milling compounding under an inert atmosphere to obtain a composite fuel additive.

[0103] Comparative Example 2

[0104] This invention provides a nano-magnesium hydride-attapulgite composite fuel additive, which is composed of nano-magnesium hydride and modified attapulgite carrier in a mass ratio of 1:5; wherein the modified attapulgite carrier is a surface-grafted graphene-coated composite carrier material.

[0105] The composite carrier material is prepared by the following method:

[0106] (a) Graphene oxide, attapulgite and kaolin were ultrasonically dispersed in an aqueous phase at a dry basis mass ratio of 0.5:60:5 to form a composite slurry;

[0107] (b) Add a reducing agent to the composite slurry. The amount of reducing agent added is 1 times the dry basis mass of graphene oxide. Perform a hydrothermal reaction to reduce the graphene oxide and interweave it with attapulgite and kaolin sheets to obtain a graphene-coated composite carrier precursor.

[0108] (c) The precursor and pyromellitic chloride are subjected to a surface grafting reaction in an organic phase, wherein the mass ratio of pyromellitic chloride to the precursor is 1:100, and modified attapulgite is obtained after the reaction.

[0109] The reducing agent is ascorbic acid.

[0110] The hydrothermal reaction temperature is 120-180℃, and the reaction time is 6-24 hours.

[0111] The surface grafting reaction was carried out under the catalysis of an organic base, which was triethylamine, with a molar ratio of 1:1 to pyromellitic acid chloride; the reaction temperature was 70-80℃, and the reaction time was 2-3 hours.

[0112] The organic phase is an anhydrous organic solvent, which is selected from one or more of N,N-dimethylformamide, toluene, and dichloromethane.

[0113] Among them, the nano-magnesium hydride is prepared by mechanical grinding hydrogenation or liquid phase chemical method, and the particle size of the nano-magnesium hydride is 20 nanometers-200 nanometers.

[0114] This application provides a method for preparing a nano-magnesium hydride-attapulgite composite fuel additive, comprising the following steps:

[0115] S1. Preparation of modified attapulgite;

[0116] S2. The composite carrier obtained in S1 and nano-magnesium hydride are mixed in a certain mass ratio and then subjected to mechanochemical ball milling under an inert atmosphere to obtain a composite fuel additive.

[0117] Comparative Example 3

[0118] This application contains only nano-magnesium hydride as a fuel additive.

[0119] Comparative Example 4

[0120] This application contains only a modified attapulgite carrier as a fuel additive.

[0121] control group

[0122] This application is based on diesel fuel.

[0123] Performance testing

[0124] The materials from Examples 1-3, Comparative Examples 1-4, and the control group were tested. Each material was added to the same batch of No. 0 diesel fuel at a dosage of 200 ppm and ultrasonically dispersed for 30 minutes to form a stable suspension. The emission and combustion performance of each fuel composition were tested using a single-cylinder diesel engine bench under the same standard operating conditions (2000 rpm, 75% load). The test results are shown in Table 1 below.

[0125] Table 1 Performance test results of compound fuel additives

[0126] ;

[0127] Table 1 shows that the support modified by "graphene coating + trimesoyl chloride grafting" improves the smoke reduction rate compared with the traditional acid activation + silane modification support, verifying the superiority of the support modification technology. When nano-magnesium hydride is used alone, the smoke reduction rate is only 12.6% and sedimentation occurs, confirming the necessity of the support loading strategy. Example 1 (with 0.01% cerium-based catalyst added) significantly increased the smoke reduction rate from 22.9% to 44.0% compared to Comparative Example 2 with the same support and nano-magnesium hydride, with CO and HC emission reduction rates increasing by 12.0 and 10.7 percentage points respectively, and fuel consumption rate decreasing from 3.8% to 6.8%. This confirms the multiplier effect brought about by the hydrogen-oxygen synergistic catalytic mechanism of "in-situ generation of hydroxyl radicals by active hydrogen and active oxygen"; all examples achieved fuel savings of 6.2%-7.5%, smoke reduction of 44%-52%, CO reduction of 26.8%-31.2%, and HC reduction of 23.1%-27.5%, with no significant sedimentation, and were comprehensively superior to the comparative examples. Among them, Example 2 (ratio 1:10:0.05) had the best overall effect; each comparative example verified the individual role of the carrier, the limitations of traditional modification methods, and the insufficiency of a single active component, forming a complete logical chain, which fully demonstrates the substantial breakthrough of this invention in carrier modification, component synergy, and dispersion stability.

[0128] like Figure 2As shown, the material exhibits a clear and well-developed three-dimensional porous network framework structure. This framework is composed of numerous interwoven and overlapping one-dimensional nanofibers, forming a macroscopic morphology with abundant porosity and a large specific surface area. This structural feature is consistent with the natural nanofiber morphology of attapulgite, indicating that the structure of attapulgite was well preserved during the preparation process, without severe agglomeration or damage. This three-dimensional network provides ideal physical support and a large contact area for subsequent loading of functional components. Numerous nanoscale spherical or near-spherical particles are uniformly distributed throughout the surface and pores of the entire network framework.

[0129] This application provides a nano-magnesium hydride-attapulgite composite fuel additive. In this method, a graphene-coated and trimesoyl chloride-grafted attapulgite carrier is prepared. The physical barrier network of the graphene sheets isolates the nano-magnesium hydride particles, and the strong chemical interaction between the grafted functional groups and the nano-magnesium hydride achieves anchoring. This synergistically solves the core problems of unstable dispersion, easy agglomeration and deactivation of nano-active components in non-polar fuels, as well as insufficient carrier compatibility and anchoring ability. Simultaneously, relying on this functional carrier, a hydrogen storage material (nano-magnesium hydride) is organically integrated with a highly efficient combustion catalyst (cerium-based compound). Under the high-temperature environment of the combustion chamber, the highly active hydrogen species released by the decomposition of nano-magnesium hydride can both hydrogenate and crack fuel macromolecules and soot precursors, accelerating combustion. The chain reaction, with its "micro-explosion" effect, can improve fuel atomization and reduce the maximum combustion temperature to decrease nitrogen oxide generation. Cerium-based compounds provide continuous active oxygen for deep oxidation of soot through their oxygen storage and release function. The "H・-O" highly active atmosphere formed by the two generates strong oxidizing hydroxyl radicals, achieving efficient low-temperature oxidation of soot. The physical improvement and chemical catalytic effects work synergistically in time and space to construct an efficient combustion path throughout the entire process. In addition, this invention adopts a preparation process that integrates mechanical grinding hydrogenation, hydrothermal synthesis, and surface grafting chemistry. The process is clear, the parameters are controllable, and the active components are protected under an inert atmosphere, making it easy to scale up. Ultimately, it comprehensively overcomes the problems of single function of active components and poor carrier adaptability in existing technologies, achieving the dual goals of improving combustion efficiency and reducing pollutant emissions.

[0130] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A nano-hydrogenated magnesium-attapulgite composite fuel additive, characterized in that, The composite fuel additive comprises nano-magnesium hydride, a modified attapulgite carrier, and a cerium-based combustion-supporting catalyst, with a mass ratio of 1:(5-20):(0.01-0.1). The modified attapulgite carrier is a surface-grafted graphene-coated composite carrier material. The cerium-based combustion-supporting catalyst is nano-cerium oxide or cerium naphthenate. The modified attapulgite carrier is prepared by the following method: (a) Graphene oxide, attapulgite and kaolin are ultrasonically dispersed in an aqueous phase at a dry basis mass ratio of (0.5-5):(60-90):(5-30) to form a composite slurry; (b) Add a reducing agent to the composite slurry, wherein the amount of the reducing agent added is 1-10 times the dry basis mass of the graphene oxide, and carry out a hydrothermal reaction to reduce the graphene oxide and interweave it with the attapulgite and kaolin sheets to obtain a graphene-coated composite carrier precursor. (c) The composite support precursor is subjected to a surface grafting reaction with trimesoyl chloride in an organic phase, wherein the mass ratio of trimesoyl chloride to the composite support precursor is (1-10):100, and the modified attapulgite support is obtained after the reaction.

2. A nano-hydrogenated magnesium-magadite composite fuel additive according to claim 1, characterized in that, The reducing agent is ascorbic acid.

3. The nano-magnesium hydride-attapulgite composite fuel additive according to claim 1, characterized in that, The hydrothermal reaction temperature is 120-180℃, and the reaction time is 6-24 hours.

4. The nano-magnesium hydride-attapulgite composite fuel additive according to claim 1, characterized in that, The surface grafting reaction is carried out under the catalysis of an organic base, wherein the organic base is triethylamine, and the molar ratio of triethylamine to pyromellitic chloride is (1.0-2.5):1, the reaction temperature is 70-80℃, and the reaction time is 2-3 hours.

5. The nano-magnesium hydride-attapulgite composite fuel additive according to claim 1, characterized in that, The organic phase is an anhydrous organic solvent, wherein the anhydrous organic solvent is selected from one or more of N,N-dimethylformamide, toluene, and dichloromethane.

6. The nano-magnesium hydride-attapulgite composite fuel additive according to claim 1, characterized in that, The nano-magnesium hydride is prepared by mechanical grinding hydrogenation or liquid phase chemical method, wherein the particle size of the nano-magnesium hydride is 20 nanometers-200 nanometers.

7. A method for preparing a composite fuel additive based on any one of claims 1-6, characterized in that, Includes the following steps: S1. Preparation of modified attapulgite carrier, wherein the modified attapulgite carrier is prepared by the following method: (a) Graphene oxide, attapulgite and kaolin are ultrasonically dispersed in an aqueous phase at a dry basis mass ratio of (0.5-5):(60-90):(5-30) to form a composite slurry; (b) Add a reducing agent to the composite slurry, wherein the amount of the reducing agent added is 1-10 times the dry basis mass of the graphene oxide, and carry out a hydrothermal reaction to reduce the graphene oxide and interweave it with the attapulgite and kaolin sheets to obtain a graphene-coated composite carrier precursor. (c) The composite support precursor and pyromellitic chloride are subjected to a surface grafting reaction in an organic phase, wherein the mass ratio of pyromellitic chloride to the composite support precursor is (1-10):100, and the modified attapulgite support is obtained after the reaction. S2. The modified attapulgite carrier, nano-magnesium hydride and cerium-based combustion catalyst obtained in S1 are mixed in a certain mass ratio and then subjected to mechanochemical ball milling compounding under an inert atmosphere to obtain the composite fuel additive.

8. A fuel composition, characterized in that, It comprises a base fuel and a compound fuel additive as described in any one of claims 1-6, wherein the amount of the compound fuel additive added is 10-500 ppm by mass of the fuel.

9. The use of the fuel composition of claim 8 in reducing soot emissions from diesel engines.

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