Non-noble metal catalysts and methods of making and uses thereof for the selective cleavage of the furan ring c-o bond of furfural to direct production of 1,5-pentanediol

Abstract

This invention relates to the field of biomass catalytic conversion technology, and particularly to a non-noble metal catalyst, preparation method, and uses of furfural-based selective cleavage of C-O bonds in furan rings to produce 1,5-pentanediol. The catalyst comprises a first metal component, a second metal component, and an oxide support; the first metal component is selected from one or two of Co and Ni; the second metal component is selected from one or more of Mn, Sr, Ce, and Sn; the support metal component is selected from one or more of Zr, Al, Ti, Si, Mg, and Zn; based on the total weight of the catalyst, the oxide content of the first metal component is 20 wt.%~60 wt.%, the oxide content of the second metal component is 1 wt.%~20 wt%, and the oxide support content is 20 wt.%~70 wt%.

Description

Technical Field

[0001] This invention relates to the field of biomass catalytic conversion technology, and in particular to a non-precious metal catalyst based on furfural for the selective cleavage of CO bonds in the furan ring to produce 1,5-pentanediol, its preparation method, and its uses. Background Technology

[0002] Biomass resources have become a core green resource to replace traditional fossil energy and solve the energy crisis and environmental dilemma. Its efficient and high-value conversion and utilization technologies have become a key global research direction and cutting-edge hotspot in the fields of energy, chemical engineering and materials science.

[0003] Furfural is one of the most valuable core platform compounds in biomass conversion systems. Its raw material sources are extremely wide-ranging; it can be prepared from inexpensive and readily available agricultural and forestry wastes such as corn cobs, crop straw, cottonseed hulls, and sawdust through acid-catalyzed hydrolysis, realizing the resource reuse of agricultural by-products and achieving both economic and ecological benefits. From a molecular structure perspective, furfural contains highly active furan rings and aldehyde functional groups, exhibiting great potential for chemical modification. Through controlled directional catalytic reactions such as hydrogenation, ring-opening, and deoxygenation, it can be converted into a series of high-value-added fine chemicals such as 1,5-pentanediol, tetrahydrofurfural, and 1,2-pentanediol, widely meeting the raw material needs of high-end chemicals, new materials, and biomedicine, making it a key intermediate connecting biomass raw materials and high-end chemical products.

[0004] 1,5-Pentanediol, as a long-chain diol fine chemical raw material, possesses excellent flexibility, weather resistance, and adhesion. It is a core raw material for synthesizing high-end polyester resins, high-performance polyurethane elastomers, environmentally friendly water-based coatings, and novel plasticizers. It can also serve as an important pharmaceutical intermediate for the synthesis and preparation of various drugs. With the rapid development of downstream new materials, high-end pharmaceuticals, and high-end equipment manufacturing industries, the market demand for high-quality 1,5-pentanediol is increasing year by year, and the supply-demand gap continues to widen, indicating a very broad prospect for industrialization. Currently, the preparation of 1,5-pentanediol through the hydrogenation and ring-opening of biomass furfural is the optimal route to replace the traditional petroleum-based synthesis route and achieve green production of 1,5-pentanediol. However, this process still has significant technical shortcomings. The precise design and controllable preparation of catalysts are the core technical bottlenecks restricting its industrialization. Specific problems are concentrated in the following five aspects: First, precious metal catalysts have extremely poor industrial applicability. Current laboratory studies show that platinum (Pt), ruthenium (Ru), and palladium (Pd)-based catalysts exhibit excellent catalytic activity for the ring-opening reaction of furfural hydrogenation, with high conversion rates and initial efficiencies. However, these precious metals are scarce in natural reserves and expensive in the market, resulting in high catalyst preparation costs. Furthermore, problems such as metal loss and activity decay during the reaction significantly increase production and operating costs, making them completely unsuitable for the economic requirements of large-scale industrial continuous production and hindering their industrial application.

[0005] Second, non-precious metal catalysts exhibit low catalytic selectivity. While existing non-precious metal-based catalysts such as iron, copper, and nickel possess advantages such as low cost and abundant reserves, they generally suffer from insufficient number of active sites and poor uniformity of metal active component dispersion. Furthermore, the electronic structure and acid-base properties of the catalyst surface are difficult to precisely control, making it impossible to achieve directional selective cleavage of the C2-O1 bond in furfural-furan rings. This easily triggers side reactions during the reaction, generating large amounts of byproducts such as tetrahydrofurfuryl alcohol and 1,2-pentanediol. Consequently, the selectivity of the target product, 1,5-pentanediol, is difficult to exceed 65%, resulting in low product purity, high separation difficulty, and severely reduced raw material utilization and product economic benefits.

[0006] Third, traditional catalyst preparation processes lead to insufficient cycle stability. Currently, commonly used industrial and laboratory methods such as impregnation and simple co-precipitation produce catalysts with poor overall structural performance, generally exhibiting small specific surface area and underdeveloped pore structure. Simultaneously, the interfacial interaction between the active metal component and the support is weak, resulting in poor bonding stability. Under the high-temperature, high-pressure hydrogenation reaction environment, the active metal is highly susceptible to agglomeration, migration, sintering, and even detachment, causing rapid degradation of catalyst activity, minimal number of cycles, and short service life. This significantly increases catalyst replacement and maintenance costs in industrial production.

[0007] Fourth, the precision of catalyst surface structure control is insufficient. The core challenge in the preparation of 1,5-pentanediol by furfural hydrogenation ring-opening lies in the precise control of the adsorption configuration and ring-opening pathway of the reactants, which is closely related to the oxygen vacancy concentration and basic site density on the catalyst surface. Existing technologies cannot achieve precise matching between oxygen vacancies and basic active sites, making it difficult to accurately adsorb and activate furfural molecules, effectively eliminate the steric hindrance effect during the furan ring-opening process, and guide the reaction towards the target ring-opening pathway, thus restricting the improvement of the selectivity of the target product from a microscopic mechanism perspective.

[0008] Fifth, some existing processes have low levels of greenness and industrialization. Some improved catalysts have problems such as cumbersome preparation processes, complex process parameters, and harsh reaction conditions, requiring a reaction environment with high temperature, high pressure, and high hydrogen partial pressure, resulting in high overall production energy consumption. At the same time, the preparation and reaction processes easily generate pollutants such as wastewater and waste residue, and the cost of treating these three wastes is high. This is not in line with the current industry development trend of green and low-carbon chemical engineering, and it is difficult to achieve large-scale, green industrial production.

[0009] In summary, current technologies for the hydrogenation of furfural to 1,5-pentanediol generally suffer from numerous problems, including high catalyst costs, poor selectivity, weak stability, difficulty in microstructure control, and a lack of green processes, which significantly hinder the industrialization of biomass-based 1,5-pentanediol. Therefore, developing a novel non-precious metal catalyst with low cost, high selectivity, and high cycle stability, and developing a simple, mild, and scalable preparation technology to overcome the core shortcomings of existing technologies, is of significant theoretical research value and practical engineering significance for realizing the high-value utilization of agricultural and forestry biomass waste, promoting the green industrial production of 1,5-pentanediol, and improving the biomass chemical industry chain. Summary of the Invention

[0010] Purpose of the invention: To provide a more effective non-precious metal catalyst, preparation method and application for the selective cleavage of CO bonds in furan rings to 1,5-pentanediol based on furfural, the specific purpose of which is described in several substantial technical effects in the detailed embodiments section.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: A non-noble metal catalyst for the selective cleavage of the CO bond in the furan ring and the directional formation of 1,5-pentanediol based on furfural, characterized in that it comprises a first metal component, a second metal component and an oxide support; The first metal component is selected from one or two of Co and Ni; The second metal component is selected from one or more of Mn, Sr, Ce, and Sn; The carrier metal component is selected from one or more of Zr, Al, Ti, Si, Mg, and Zn; Based on the total weight of the catalyst, the content of the first metal component oxide is 20 wt.% to 60 wt.%, the content of the second metal component oxide is 1 wt.% to 20 wt%, and the content of the oxide support is 20 wt.% to 70 wt%.

[0012] A further technical solution of the present invention is that the catalyst is a composite oxide formed by the co-precipitation of multiple metals, the metal components are atomically dispersed, and the surface has a controllable distribution of oxygen vacancies and basic sites. A further technical solution of the present invention is that the catalyst can achieve tilted adsorption of the C2-end of furan-like reactants and directional cleavage of the C2-O1 bond of the furan ring by controlling the concentration of oxygen vacancies and the density of basic sites on the surface. The catalyst is prepared by a soft template coupled homogeneous coprecipitation-hydrothermal crystallization process, which can induce the spontaneous assembly of multiple metal ions under weakly alkaline conditions to form a layered hydroxide precursor with a hydrotalcite-like structure. After precise control by gradient crystallization, the precursor exhibits a typical nanosheet stacked morphology. After calcination, the layered topology of the precursor is partially retained and transformed into a hydrotalcite-like derived porous composite oxide structure, which can not only achieve atomic-level dispersion of metal components, but also achieve precise control of surface oxygen vacancies and basic sites. The catalyst combines the structural advantages of high specific surface area and strong surface alkalinity of hydrotalcite materials with the performance of multi-metal synergistic catalysis.

[0013] A method for preparing a non-noble metal catalyst based on the selective cleavage of the CO bond in the furan ring of furfural to generate 1,5-pentanediol, characterized in that... It comprises a first metal component, a second metal component, and an oxide support; The first metal component is selected from one or two of Co and Ni; The second metal component is selected from one or more of Mn, Sr, Ce, and Sn; The carrier metal component is selected from one or more of Zr, Al, Ti, Si, Mg, and Zn; Based on the total weight of the catalyst, the content of the first metal component oxide is 20 wt.% to 60 wt.%, the content of the second metal component oxide is 1 wt.% to 20 wt%, and the content of the oxide support is 20 wt.% to 70 wt%. (1) Dissolve the structure-regulating additive in an alcohol-water mixed solvent, then add the first metal soluble salt, the second metal soluble salt and the carrier metal soluble salt, stir at room temperature for 30 min ~ 120 min to form a clear and transparent multi-metal complex homogeneous solution. (2) Slowly add an alkaline precipitant to the homogeneous solution of the multi-metal complex, control the pH of the system to 9.0~13.0, and stir at a constant temperature of 35℃~60℃ for 30 min~180 min to achieve simultaneous co-precipitation of all metal ions; (3) The precipitate is subjected to two-stage gradient crystallization: the first stage is static aging at 40 ℃~80 ℃ for 2 h~8 h, and the second stage is hydrothermal crystallization at 90 ℃~150 ℃ for 2 h~4 h; (4) The crystallized product was washed alternately with deionized water and ethanol until the filtrate was neutral and free of NO3. - Detected, then subjected to gradient drying; (5) The dried precursor was calcined in air under programmed heating and then naturally cooled to obtain a non-precious metal multi-component oxide catalyst. A further technical solution of the present invention is that the structure regulating additive is selected from one or more of glucose, CTAB, chitosan, and citric acid, and the amount added is 2 wt.% to 15 wt.% of the total mass of all metal salts. A further technical solution of the present invention is that the first metal soluble salt, the second metal soluble salt, and the carrier metal soluble salt are all selected from one or more of nitrates, acetates, and chlorides; in the alcohol-water mixed solvent, the volume ratio of deionized water to anhydrous ethanol is 1:1 to 6:1; and the alkaline precipitant is one or two of NaOH, Na2CO3, KOH, K2CO3, and ammonia. A further technical solution of the present invention is that the gradient drying is as follows: first, vacuum drying at 60℃ for 6 h to 10 h, followed by forced-air drying at 100℃ for 2 h to 8 h; the programmed temperature rise calcination is as follows: rising to 350℃ to 550℃ at a rate of 1℃ / min to 3℃ / min, and holding at that temperature for 3 h to 6 h; It also includes an optional reduction step: reducing the calcined catalyst at 300℃~500℃ for 1 h~5 h in a 30% V H2 / N2 mixed atmosphere. Application of non-noble metal catalysts based on the selective cleavage of the CO bond in the furan ring of furfural to produce 1,5-pentanediol in the hydrogenation of furfural to prepare 1,5-pentanediol. A method for the selective cleavage of the CO bond in the furan ring of furfural to generate 1,5-pentanediol, characterized in that a non-noble metal catalyst based on the selective cleavage of the CO bond in the furan ring of furfural as described in any one of the above methods is used, and the reaction conditions are: reaction temperature 150 ℃~200 ℃, hydrogen pressure 2 MPa~6 MPa, reaction time 2 h~10 h, and the reaction solvent is selected from ethanol, isopropanol, and water.

[0014] A non-noble metal catalyst based on furfural for the selective cleavage of the CO bond in the furan ring to produce 1,5-pentanediol, wherein the catalyst is any one of the following: Option 1: Ni-Ce / Al2O3 catalyst (additive: CTAB) (1) Mix 400 mL of deionized water with 100 mL of anhydrous ethanol, add 3.20 g of CTAB and stir to dissolve; add 58.20 g of nickel nitrate hexahydrate, 8.70 g of cerium nitrate hexahydrate, and 49.50 g of aluminum nitrate nonahydrate, stir for 90 min to form a transparent homogeneous complex solution; slowly add KOH alkaline solution dropwise with stirring until pH=9.8, and then add the solution at 50 °C. o Continue stirring for 120 minutes to complete co-precipitation; transfer the suspension to a hydrothermal reactor and pass it through a 65°C bath. o C aging for 8 hours, 95 o Hydrothermal crystallization at C for 4 h, the product was washed alternately with deionized water and ethanol until neutral, 60 o Vacuum drying at 100°C for 8 hours. o Drying at 1.5°C with forced air for 3 hours; o C / min increased to 480 o Calcination at C for 5 h, followed by calcination at 350 °C in a 30% V H2 / N2 mixed atmosphere. o After C reduction for 3 h, a Ni / CeO2-Al2O3 catalyst was obtained, in which the mass fraction of NiO was 46.9%, the mass fraction of CeO2 was 10.8%, and the mass fraction of Al was 42.3%. Option 2: Co-Sr / MgO catalyst (additive: chitosan) (1) Mix 300 mL of deionized water with 100 mL of ethanol, add 1.20 g of chitosan to dissolve; add 43.5 g of cobalt nitrate, 5.8 g of strontium chloride hexahydrate, and 48.2 g of magnesium nitrate hexahydrate in sequence, stir for 90 min to form a transparent homogeneous complex solution; slowly add NaOH alkaline solution dropwise with stirring until pH=10.0, and then add the solution at 50 °C. o Continue stirring for 120 min to complete co-precipitation; transfer the suspension to a hydrothermal reactor and heat for 70 minutes. o Aging at C for 6 h, followed by hydrothermal crystallization at 100 °C for 3 h, the product was washed alternately with deionized water and ethanol until neutral, and then... o Vacuum drying at 100°C for 8 hours. o C-air drying for 3 hours; after drying, 500℃ o Calcination at C for 4 h, followed by calcination at 400 °C in a 30% VH2 / N2 mixed atmosphere. o C reduction for 3 h yielded a Co / SrO-MgO catalyst, wherein the mass fraction of CoO was 56%, the mass fraction of SrO was 11.3%, and the mass fraction of MgO was 32.7%. Option 3: Co-Sn / Al2O3 catalyst (additive: citric acid) (1) Mix 350 mL of water with 70 mL of ethanol, add 4.50 g of citric acid; add 41.30 g of cobalt nitrate hexahydrate, 5.20 g of tin chloride, and 50.10 g of magnesium nitrate nonahydrate, stir for 80 min to form a transparent homogeneous complex solution; slowly add ammonia water dropwise with stirring until pH=9.0, 55 o Stirring at C for 100 min for initial co-precipitation; then transfer the suspension to a hydrothermal reactor, first at 80°C. o C aging for 4 hours, then at 110 o C hydrothermal crystallization for 2 hours, followed by washing and drying at 550°C. o Calcination at C for 3 h, then in a 30 vol.% H2 / N2 atmosphere at 380 °C o C reduction for 3 h yielded a Co-Sn / Al2O3 catalyst, wherein the mass fraction of CoO was 54.6%, the mass fraction of SnO2 was 15.4%, and the mass fraction of Al2O3 was 30.0%. Option 4: Co-Mn / ZrO2 catalyst (additive: glucose) (1) Catalyst preparation: 300 mL of deionized water and 100 mL of anhydrous ethanol were mixed, and 5.0 g of glucose was added and stirred until completely dissolved; 48.4 g of cobalt nitrate hexahydrate, 6.0 g of manganese nitrate hexahydrate, and 52.8 g of zirconium nitrate pentahydrate were added sequentially, and stirred at room temperature for 90 min to form a transparent homogeneous complex solution; a mixed alkaline solution of NaOH and Na2CO3 was slowly added dropwise under stirring until the pH of the system reached 10.0, and the solution was then stirred at 50 °C. o Continue stirring for 120 min to complete co-precipitation; transfer the suspension to a hydrothermal reactor and heat at 70°C. o Static aging at 100°C for 6 hours o Hydrothermal crystallization at C for 3 h; the product was washed alternately with deionized water and ethanol until neutral, then at 60 °C. o Vacuum drying at 100°C for 8 hours. o C-air drying for 3 hours; under air atmosphere at 2 o C / min increased to 500 o Calcination at C for 4 h, followed by calcination at 350 °C in a 30% V H2 / N2 mixed atmosphere. o C reduction for 2 h yielded a Co / Mn2O3-ZrO2 composite oxide catalyst; wherein the mass fraction of CoO was 42.6%, the mass fraction of Mn2O3 was 5.6%, and the mass fraction of ZrO2 was 51.8%. Option 5: Ni-Mn / ZnO catalyst (additives: glucose + citric acid) Mix 300 mL of water with 100 mL of ethanol, add 3.00 g of glucose and 2.00 g of citric acid; add 38.20 g of nickel nitrate hexahydrate, 6.00 g of manganese nitrate hexahydrate, and 47.60 g of zinc nitrate hexahydrate, and stir for 90 min to form a transparent homogeneous complex solution; slowly add Na₂CO₃ alkaline solution dropwise while stirring until the pH reaches 9.5. o Stirring at C for 100 min for initial co-precipitation; then transfer the suspension to a hydrothermal reactor, first at 80°C. o Age at C for 4 hours, then at 130 o C hydrothermal crystallization for 2 hours, 500 o Calcination at C for 4 h, and finally heated at 350 °C in a 30 vol.% H2 / N2 atmosphere. o After C reduction for 3 h, a Ni-Mn / ZnO catalyst was obtained, in which the mass fraction of NiO was 40.1%, the mass fraction of Mn2O3 was 6.7%, and the mass fraction of ZnO was 53.2%.

[0015] The present invention, employing the above technical solution, has the following beneficial effects compared to the prior art: The present invention achieves a breakthrough improvement in catalytic performance through multi-component synergy and innovative preparation process, and its core mechanism of action is as follows: (1) Homogeneous complexation of fully soluble salts: The support dissolves and complexes with the active metal salt in the form of soluble salts, avoiding the problem of uneven metal dispersion caused by solid supports in traditional supported catalysts, realizing atomic-level mixing of metal components and greatly increasing the number of active sites; (2) Dual role of complexation-soft template: The additive not only coordinates with metal ions to form stable complexes, inhibiting the rapid nucleation and aggregation of metal ions, but also pyrolyzes during the calcination process to form mesoporous channels, thereby regulating the specific surface area and pore structure of the catalyst and improving the diffusion efficiency of reactants and products. (3) Gradient process control of structure: Gradient crystallization makes the crystal structure more regular, and gradient drying avoids hard agglomeration of particles, ultimately obtaining a thin-layer, highly dispersed composite oxide structure. (4) Synergistic optimization of oxygen vacancies and alkalinity: The introduction of the second metal component and the precise control of the calcination process simultaneously regulate the concentration of oxygen vacancies and the density of alkaline sites on the catalyst surface, so that furfural is bound to the catalyst surface in a C2-end tilted adsorption mode, effectively overcoming the steric hindrance of furan ring opening, directionally breaking C2-O1 bonds, and inhibiting the occurrence of side reactions. (5) Enhanced structural stability: The composite oxide skeleton formed by the co-precipitation of multiple metals has a stable structure and strong interfacial interaction between the metal components and the support, which effectively inhibits the sintering and loss of metal particles and improves the cycle stability of the catalyst. Attached Figure Description

[0016] To further illustrate the present invention, the following description is provided in conjunction with the accompanying drawings: Figure 1 This is an electron microscope image of the precursor after calcination; Figure 2 A bar chart showing the effects of the invention. Detailed Implementation The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0017] This invention provides a non-precious metal multi-component composite oxide catalyst. This catalyst, through an innovative soft-template coupled homogeneous co-precipitation-hydrothermal crystallization process, induces the spontaneous assembly of multi-metal ions under weakly alkaline conditions to form a layered hydroxide precursor with a hydrotalcite-like structure. Through precise gradient crystallization control, the precursor exhibits a typical nanosheet stacked morphology. After calcination, the layered topology of the precursor is partially retained and transformed into a hydrotalcite-derived porous composite oxide structure. Figure 1 This catalyst not only achieves atomic-level dispersion of the metal components but also enables precise control of surface oxygen vacancies and basic sites. It combines the structural advantages of high specific surface area and strong surface alkalinity of hydrotalcite materials with the performance advantages of synergistic catalysis by multiple metals. It can significantly improve the catalytic activity, selectivity, and stability of the furfural hydrogenation to 1,5-pentanediol reaction, while effectively reducing catalyst preparation costs and simplifying process steps, fully meeting the needs of industrial applications. The non-precious metal multi-component composite oxide catalyst of this invention is composed of a first metal component, a second metal component, and a support metal component. 1. First metal component: selected from one or both of Co and Ni, serving as the active center for hydrogenation and the active site for CO bond breaking, with an oxide content of 20 wt.% ~ 60 wt.%; 1 wt.% ~ 20 wt.% of the total catalyst weight. 2. Second metal component: selected from one or more of Mn, Sr, Ce, and Sn, used to regulate the basic site density and oxygen vacancy concentration on the catalyst surface, with an oxide content of 1 wt.% to 20 wt.% of the total catalyst weight; 3. Support metal component: selected from one or more of Zr, Al, Ti, Si, Mg, and Zn, used to construct a stable composite oxide framework and improve the structural stability of the catalyst. Its oxide content is 20 wt.% to 70 wt.% of the total weight of the catalyst.

[0018] This invention employs a complexation-homogeneous precipitation coupled soft template method to prepare the catalyst, and the specific steps are as follows: 1. Preparation of a homogeneous multi-metal complex solution: Deionized water and anhydrous ethanol are mixed at a volume ratio of 1:1 to 6:1 to form an alcohol-water mixed solvent; structure-regulating and complexing additives are added to the solvent and stirred until completely dissolved to form a homogeneous template solution; the additives are selected from one or more of glucose, CTAB, chitosan, and citric acid, and the amount added is 2 wt.% to 15 wt.% of the total mass of all metal salts; then, soluble first metal salt, second metal salt, and soluble carrier metal salt are added to the template solution in sequence, and stirred at room temperature for 30 min to 120 min to allow all metal ions to fully coordinate and complex with the additive molecules to form a clear and transparent homogeneous multi-metal complex solution; 2. Homogeneous simultaneous coprecipitation reaction: One or two of the alkaline precipitants NaOH, Na2CO3, KOH and ammonia water are slowly added dropwise to the above multi-metal complex homogeneous solution through a constant pressure dropping funnel at a rate of 1 mL / min to 3 mL / min. The pH value of the system is controlled to be stable at 9.0 to 13.0. The mixture is stirred at 35℃ to 60℃ for 30 min to 180 min to achieve simultaneous coprecipitation of all metal ions. 3. Gradient crystallization aging: The precipitated suspension is transferred to a hydrothermal reactor and statically aged at 40℃~80℃ for 2h~8h to complete the initial growth of crystal nuclei and structural regularization; then hydrothermally crystallizes at 90℃~150℃ for 2h~4h to enhance the assembly of the layered structure of the catalyst precursor. 4. Gradient washing and agglomeration-free drying: Remove the crystallized product and wash it alternately with deionized water and anhydrous ethanol 3-5 times until the filtrate has a pH of 7.0 and is free of Cl. - NO3 - Detected; then first at 60 o Vacuum drying at C for 6-10 hours, then at 100°C o Drying in C-air for 2 h ~ 8 h; to obtain the catalyst precursor; 5. Programmed temperature roasting and defect-controlled activation: The precursor is placed in a tube furnace and heated to 350 °C at a rate of 1 °C / min to 3 °C / min. o C~550 o C, heat for 3-6 hours. After natural cooling, a non-precious metal multi-component composite oxide catalyst is obtained. 6. Optional reduction step: The calcined catalyst is reduced at 300℃~500℃ for 1 h~5 h in a 5% H2 / Ar mixed atmosphere to construct highly active low-valence metal active sites.

[0019] The first metal soluble salt, the second metal soluble salt, and the carrier metal soluble salt are all selected from one or more of nitrates, acetates, and chlorides, such as nickel nitrate, cobalt nitrate, manganese nitrate, cerium nitrate, zirconium nitrate, and aluminum nitrate.

[0020] The catalyst is used in the hydrogenation of furfural to prepare 1,5-pentanediol, specifically under the following conditions: reaction temperature 150°C. o C~200 o C, hydrogen pressure is 2 MPa ~ 6 MPa, reaction time is 2 ~ 6 h, reaction solvent is selected from ethanol, isopropanol, water or a mixture thereof; catalyst amount is 5% ~ 15% of furfural mass.

[0021] Figure 1 shows the scanning electron microscope (SEM) image of the catalyst precursor after calcination, with a scale bar of 200 nm and a magnification of 50.0 kx. The image clearly shows a well-defined, hydrotalcite-derived porous structure with regularly stacked nanosheets. The sheets are uniform in thickness and loosely distributed, with no obvious metal particle agglomeration or clumping. The overall morphology is regular and the pore structure is well-developed. From the microstructural characteristics, the stacked sheet morphology provides the catalyst with a larger specific surface area and abundant pores, offering ample space for furfural molecule adsorption, mass transfer, and hydrogenation ring-opening reactions. Simultaneously, the metal components are highly dispersed in the sheet structure, with no obvious crystallite aggregation. This confirms that the soft-template coupled homogeneous co-precipitation-hydrothermal crystallization and gradient crystallization drying preparation process of this invention can achieve atomic-level dispersion of multiple metals, successfully constructing a layered composite oxide framework with controllable oxygen vacancies and basic sites.

[0022] Figure 1 visually demonstrates that the present invention employs a soft template-homogeneous coprecipitation-gradient crystallization process to successfully prepare a hydrotalcite-derived composite oxide catalyst with stacked nanosheets, highly dispersed metals, and well-developed porous structure. This process verifies the precise control of the catalyst structure by the preparation process at the microscopic morphology level, and solves the defects of traditional catalysts such as metal agglomeration, small specific surface area, and underdeveloped pores.

[0023] This strongly demonstrates the feasibility of the design concept of spontaneous assembly of multi-metal co-precipitation and preservation of gradient crystallization topology in this invention. It enables the atomic-level dispersion of active components and the controllable preparation of catalyst channels and lamellar morphology, providing a structural basis for the directional selective breaking of CO bonds in furfural-furan rings.

[0024] Figure 2 is a bar chart comparing the performance and catalytic effect of the catalyst after repeated use. It covers the data of multiple cycles of the optimal Co-Mn / ZrO2 catalyst of this invention, as well as the furfural conversion rate and 1,5-pentanediol selectivity of the conventional impregnation method and the additive-free coprecipitation catalyst. The bar chart shows that after six cycles, the furfural conversion rate of the catalyst of this invention remains at 100%, and the 1,5-pentanediol selectivity remains above 96%, with no significant decline. In contrast, the conventional impregnation method and the ordinary coprecipitation catalyst without additives not only have much lower initial conversion rates and selectivity than the catalyst of this invention, but also lack the advantage of cycle stability. The differences in the bar chart also clearly demonstrate the performance leap brought about by the multi-component synergy, structural regulation, and optimization of oxygen vacancies and basic sites of this invention, showing a significant performance gap compared to the control samples.

[0025] Figure 2 quantitatively demonstrates that the non-precious metal composite oxide catalyst of this invention possesses ultra-high catalytic activity, high selectivity for the target product, and excellent cycle stability. The furfural conversion rate can reach 100%, the 1,5-pentanediol selectivity is stable at 96.0%~97.7%, and the performance does not decrease significantly after 6 cycles, which is far superior to catalysts prepared by traditional impregnation method and ordinary coprecipitation.

[0026] This strongly demonstrates that the present invention fundamentally suppresses the problems of metal sintering, loss, and activity decay under high-temperature hydrogenation conditions by optimizing the metal composition ratio, synergistically regulating surface oxygen vacancies and basic sites, and constructing a stable layered oxide framework. It breaks through the technical bottlenecks of existing non-precious metal catalysts, which have low selectivity, poor stability, and short service life, and has excellent potential for continuous industrial application.

[0027] Combining the technical principles of the patent text with the characterization and performance results of the two graphs, Figure 1 verifies the scientific nature of the controllable preparation of the catalyst from the perspective of microscopic morphology and structure, while Figure 2 verifies the practical value of the catalyst from the perspective of macroscopic catalytic performance and cycle life. The two mutually corroborate each other, fully demonstrating that the non-precious metal catalyst of this invention can achieve selective and directional cleavage of the CO bond in the furfural-furan ring, and efficiently prepare 1,5-pentanediol. It has the comprehensive advantages of low cost, high activity, high selectivity, and high stability, and is fully adapted to the industrial production needs of biomass catalytic conversion.

[0028] The present invention will be further illustrated by the following embodiments, but is not limited to the following embodiments.

[0029] Example 1: Ni-Ce / Al2O3 catalyst (additive: CTAB) (1) Mix 400 mL of deionized water with 100 mL of anhydrous ethanol, add 3.20 g of CTAB and stir to dissolve. Add 58.20 g of nickel nitrate hexahydrate, 8.70 g of cerium nitrate hexahydrate, and 49.50 g of aluminum nitrate nonahydrate, and stir for 90 min to form a transparent homogeneous complex solution. Slowly add KOH alkaline solution dropwise with stirring until pH = 9.8, and then add the solution at 50 °C. o Continue stirring for 120 minutes to complete co-precipitation. Transfer the suspension to a hydrothermal reactor and pass it through a 65°C tank. o C aging for 8 hours, 95 o Hydrothermal crystallization at C for 4 h, the product was washed alternately with deionized water and ethanol until neutral, 60 o Vacuum drying at 100°C for 8 hours. o Drying at 1.5°C using forced air for 3 hours. o C / min increased to 480 o Calcination at C for 5 h, followed by calcination at 350 °C in a 30% V H2 / N2 mixed atmosphere. o After C reduction for 3 h, a Ni / CeO2-Al2O3 catalyst was obtained, in which the mass fraction of NiO was 46.9%, the mass fraction of CeO2 was 10.8%, and the mass fraction of Al was 42.3%.

[0030] (2) Evaluation of catalytic performance: 1) The activated catalyst is loaded into a high-pressure reactor, furfuryl alcohol is added, and pure hydrogen is introduced to carry out the hydrogenation reaction; 2) The product after the reaction was separated by centrifugation to obtain the upper layer product, which was then analyzed by gas chromatography; 3) At a reaction temperature of 150°C o At C, under a pressure of 6 MPa H2, the reaction was carried out in isopropanol solvent for 4 hours, with a furfural conversion rate of 100% and a 1,5-pentanediol selectivity of 96.2%.

[0031] Example 2 Co-Sr / MgO catalyst (additive: chitosan) (1) Mix 300 mL of deionized water with 100 mL of ethanol, add shell H2, react in isopropanol solvent for 4 h, furfural conversion rate is 100%, 1,5-pentanediol selectivity is 96.2%.

[0032] Example 2: Co-Sr / MgO catalyst (additive: 1.20 g polysaccharide dissolved. 43.5 g cobalt nitrate, 5.8 g strontium chloride hexahydrate, and 48.2 g magnesium nitrate hexahydrate were added sequentially, and the mixture was stirred for 90 min to form a transparent homogeneous complex solution. NaOH alkaline solution was slowly added dropwise with stirring until the pH reached 10.0, and the solution was then heated to 50 °C. oContinue stirring for 120 min to complete co-precipitation. Transfer the suspension to a hydrothermal reactor and heat for 70 minutes. o Aging at C for 6 h, followed by hydrothermal crystallization at 100 °C for 3 h, the product was washed alternately with deionized water and ethanol until neutral, and then... o Vacuum drying at 100°C for 8 hours. o Dry in a forced-air environment for 3 hours. After drying, 500°C o Calcination at C for 4 h, followed by calcination at 400 °C in a 30% V H2 / N2 mixed atmosphere. o After C reduction for 3 h, a Co / SrO-MgO catalyst was obtained, in which the mass fraction of CoO was 56%, the mass fraction of SrO was 11.3%, and the mass fraction of MgO was 32.7%.

[0033] (2) Catalytic performance 1) The operation method according to Example 1 2) At a reaction temperature of 180°C o At C, under a pressure of 4 MPa H2, the reaction was carried out in a mixed solvent of ethanol and water for 2 h, with a furfural conversion rate of 100% and a 1,5-pentanediol selectivity of 96.8%.

[0034] Example 3: Co-Sn / Al2O3 catalyst (additive: citric acid) (1) Mix 350 mL of water with 70 mL of ethanol, and add 4.50 g of citric acid. Add 41.30 g of cobalt nitrate hexahydrate, 5.20 g of tin chloride, and 50.10 g of magnesium nitrate nonahydrate, and stir for 80 min to form a transparent homogeneous complex solution. Slowly add ammonia water dropwise with stirring until the pH reaches 9.0. o Stirring at C for 100 min for initial co-precipitation. Then transfer the suspension to a hydrothermal reactor and heat at 80°C. o C aging for 4 hours, then at 110 o C hydrothermal crystallization for 2 hours, followed by washing and drying at 550°C. o Calcination at C for 3 h, then in a 30 vol.% H2 / N2 atmosphere at 380 °C o C reduction for 3 h yielded a Co-Sn / Al2O3 catalyst, in which the mass fraction of CoO was 54.6%, the mass fraction of SnO2 was 15.4%, and the mass fraction of Al2O3 was 30.0%.

[0035] (2) Catalytic performance 1) The operation method according to Example 1 2) At a reaction temperature of 190°C o At C, under a pressure of 5 MPa H2, the reaction was carried out in a mixed solvent of isopropanol and water for 2 h, with a furfural conversion rate of 100% and a 1,5-pentanediol selectivity of 96.7%.

[0036] Example 4: Co-Mn / ZrO2 catalyst (additive: glucose) (1) Catalyst preparation: 300 mL of deionized water and 100 mL of anhydrous ethanol were mixed, and 5.0 g of glucose was added and stirred until completely dissolved. 48.4 g of cobalt nitrate hexahydrate, 6.0 g of manganese nitrate hexahydrate, and 52.8 g of zirconium nitrate pentahydrate were added sequentially, and the mixture was stirred at room temperature for 90 min to form a transparent homogeneous complex solution. A mixed alkaline solution of NaOH and Na₂CO₃ was slowly added dropwise with stirring until the pH of the system reached 10.0. The solution was then stirred at 50 °C. o Continue stirring for 120 min to complete co-precipitation. Transfer the suspension to a hydrothermal reactor at 70°C. o Static aging at 100°C for 6 hours o Hydrothermal crystallization at 60°C for 3 hours. The product was washed alternately with deionized water and ethanol until neutral, then... o Vacuum drying at 100°C for 8 hours. o Drying at 2°C with forced air for 3 hours. (The rest of the text appears to be incomplete and requires further context.) o C / min increased to 500 o Calcination at C for 4 h, followed by calcination at 350 °C in a 30% V H2 / N2 mixed atmosphere. o C reduction for 2 h yielded a Co / Mn2O3-ZrO2 composite oxide catalyst. The mass fraction of CoO was 42.6%, the mass fraction of Mn2O3 was 5.6%, and the mass fraction of ZrO2 was 51.8%.

[0037] (2) Evaluation of catalytic performance: 1) The operation method according to Example 1 2) At a reaction temperature of 160°C o At C, with a pressure of 5 MPa and H2, the reaction was carried out in ethanol solvent for 4 h, resulting in a furfural conversion rate of 100% and a 1,5-pentanediol selectivity of 97.7%.

[0038] Example 5 Ni-Mn / ZnO catalyst (additives: glucose + citric acid) (1) Mix 300 mL of water with 100 mL of ethanol, add 3.00 g of glucose and 2.00 g of citric acid. Add 38.20 g of nickel nitrate hexahydrate, 6.00 g of manganese nitrate hexahydrate, and 47.60 g of zinc nitrate hexahydrate, and stir for 90 min to form a transparent homogeneous complex solution. Slowly add Na2CO3 alkaline solution dropwise while stirring until pH=9.5. o Stirring at C for 100 min for initial co-precipitation. Then transfer the suspension to a hydrothermal reactor and heat at 80°C. o Age at C for 4 hours, then at 130o C hydrothermal crystallization for 2 hours, 500 o Calcination at C for 4 h, and finally heated at 350 °C in a 30 vol.% H2 / N2 atmosphere. o After C reduction for 3 h, a Ni-Mn / ZnO catalyst was obtained, in which the mass fraction of NiO was 40.1%, the mass fraction of Mn2O3 was 6.7%, and the mass fraction of ZnO was 53.2%.

[0039] (2) Catalytic performance 1) The operation method according to Example 1 4) At a reaction temperature of 160°C o At C, under a pressure of 5 MPa and H2, the reaction was carried out in ethanol solvent for 2 h, with a furfural conversion rate of 100% and a 1,5-pentanediol selectivity of 96.0%.

[0040] Example 6: The catalyst prepared in Example 4 was recycled 6 times under the conditions of Example 4. There was no significant decrease in catalyst activity or product selectivity. Figure 2 This indicates that the catalyst has excellent stability.

[0041] Comparative Example 1 (Conventional Impregnation Method, Solid Carrier) (1) Solid Al2O3 was used as a carrier, and Ni and Ce active components were loaded by the traditional impregnation method. The proportions of other components, calcination and reduction conditions were the same as in Example 1.

[0042] (2) Catalytic performance 1) The operation method according to Example 1 2) At a reaction temperature of 150°C o At C, under a pressure of 6 MPa H2, the reaction was carried out in isopropanol solvent for 4 h, with a furfural conversion rate of 88% and a 1,5-pentanediol selectivity of 38.2%, which was significantly lower than that of the embodiments of the present invention.

[0043] Comparative Example 2 (no additives, traditional co-precipitation) Except for the absence of any structure-regulating additives, the other components, dosages, calcination and reduction conditions were exactly the same as in Example 4.

[0044] (2) Catalytic performance 1) The operation method according to Example 1 2) At a reaction temperature of 160°C o At C, with a pressure of 5 MPa and H2, the reaction was carried out in ethanol solvent for 4 h, resulting in a furfural conversion rate of 90% and a 1,5-pentanediol selectivity of 42%.

[0045] The above experiments show that the prepared catalyst significantly improves the activity, selectivity and stability of the catalyst, and has high industrial application value.

[0046] In summary, this invention discloses a non-precious metal composite oxide catalyst for the hydrogenation of furfural to 1,5-pentanediol and its preparation method, belonging to the field of biomass catalytic conversion technology. The catalyst comprises a first metal component, a second metal component, and an oxide support; the first metal component is one or two of Co and Ni, and the second metal component is one or more of Mn, Sr, Ce, and Sn. Based on the total weight of the catalyst, the oxide content of the first metal component is 20 wt.%~60 wt.%, the oxide content of the second metal component is 1 wt.%~20 wt.%, and the oxide support content is 20 wt.%~70 wt.%. This invention employs a complexation-homogeneous precipitation coupled soft template method, adding all metal components (including the support) in the form of soluble salts, along with one or two of the following structure-regulating additives: glucose, CTAB (hexadecyltrimethylammonium bromide), chitosan, and citric acid. Through a process of multi-metal homogeneous complexation, simultaneous co-precipitation, gradient crystallization, gradient drying, and programmed temperature calcination, atomic-level metal dispersion, in-situ construction of mesoporous structures, and precise control of surface oxygen vacancy and basicity site densities are achieved. This significantly optimizes the adsorption configuration of furan reactants and enhances the selective breaking of the C2-O1 bond in the furan ring. The catalyst exhibits high conversion rate, high selectivity, and excellent cycling stability in the hydrogenation of furfural to 1,5-pentanediol. Furthermore, it is free of precious metals, has a simple preparation process, low cost, and can be mass-produced, showing broad application prospects in the field of efficient biomass catalytic conversion.

[0047] Compared with the shortcomings of existing technologies: Although noble metal catalysts such as Pt, Ru, and Pd have high activity, they are scarce, expensive, and have high preparation and operation costs. They are also prone to metal loss and activity decay, which cannot meet the economic requirements of large-scale industrial production. This patent innovatively and non-obviously abandons the precious metal system, using Co and Ni as the primary non-precious metal active components throughout the entire process, combined with Mn, Sr, Ce, and Sn as secondary modified metal components, and non-precious metal oxide supports such as Zr, Al, and Ti. It utilizes abundant and inexpensive non-precious metal raw materials to construct a multi-component composite oxide catalyst, completely eliminating dependence on precious metals from the source. Simultaneously, the catalyst inhibits metal loss and activity decay through strong metal-support interface interactions, significantly reducing catalyst preparation costs and industrial operation and maintenance costs. This fully meets the economic requirements of continuous industrial production, precisely addressing the core defect of poor industrial adaptability of existing precious metal catalysts.

[0048] Compared with the shortcomings of existing technologies: traditional non-precious metal catalysts have few active sites, poor metal component dispersion, surface electronic structure and acid-base properties cannot be precisely controlled, cannot directionally break furfural-furan ring C2-O1 bonds, produce many by-products, and the selectivity of 1,5-pentanediol is difficult to exceed 65%, resulting in low raw material utilization and economic benefits. This patent innovatively employs a non-obvious, homogeneous co-precipitation-hydrothermal crystallization process coupled with a soft template. This process achieves atomic-level uniform dispersion of the first metal, second metal, and support metal in the form of soluble salts, significantly increasing the number of effective active sites. Simultaneously, through precise control of the second metal component doping and calcination process, the oxygen vacancy concentration and basicity site density on the catalyst surface can be controlled. This induces furfural molecules to adhere to the catalyst surface with a C2-end tilted adsorption configuration, overcoming the steric hindrance of the furan ring opening and selectively breaking the C2-O1 bond of the furan ring, thus inhibiting side reactions such as tetrahydrofurfuryl alcohol and 1,2-pentanediol. In the examples, the furfural conversion rate reaches 100%, and the selectivity of 1,5-pentanediol is consistently above 96.0%, reaching a maximum of 97.7%, far exceeding the selectivity limit of existing non-precious metal catalysts and completely solving the technical shortcomings of low selectivity and numerous byproducts.

[0049] Compared with the shortcomings of existing technologies: catalysts prepared by impregnation method and simple co-precipitation method have small specific surface area, underdeveloped pore structure, weak interfacial interaction between active metal and support, and are prone to metal agglomeration, migration, sintering and shedding under high temperature and high pressure hydrogenation conditions, resulting in rapid activity decay, few cycles and short service life. This patent innovatively introduces a two-stage gradient crystallization, gradient washing, and gradient drying process, which induces the spontaneous assembly of multiple metal ions under weakly alkaline conditions to form a layered hydroxide precursor similar to hydrotalcite. After calcination, the layered topology is retained, transforming it into a porous composite oxide framework derived from hydrotalcite. This structure has a high specific surface area, well-developed pore structure, and the co-precipitation of multiple metals forms a stable composite oxide framework. The interaction between the active metal and the support interface is significantly enhanced, inhibiting the agglomeration, sintering, and detachment of metal particles at the structural level. After six cycles, the catalyst activity and selectivity show no significant decline, exhibiting excellent cycle stability, effectively extending the catalyst's lifespan and reducing industrial catalyst replacement and maintenance costs.

[0050] Compared to the shortcomings of existing technologies: existing technologies cannot accurately match oxygen vacancies and basic active sites on the catalyst surface, making it difficult to accurately adsorb and activate furfural molecules, and cannot regulate the directional ring-opening pathway of furan rings. Microscopic mechanisms limit the improvement of the selectivity of target products. This patent innovatively and non-obviously utilizes the dual effects of complexation and soft templates of structure-regulating additives (glucose, CTAB, chitosan, citric acid). On the one hand, it coordinates with metal ions to precisely regulate the nucleation and growth behavior of metals; on the other hand, it combines gradient crystallization and programmed temperature calcination processes to precisely and synchronously regulate the concentration of oxygen vacancies and the density of basic sites on the catalyst surface, achieving a precise match between oxygen vacancies and basic active sites. It precisely adsorbs and activates furfural molecules at the microscopic level, guiding the furan ring to open along the target path, eliminating steric hindrance effects, and fundamentally solving the technical problem of insufficient precision in surface structure regulation and inability to directionally guide the reaction path.

[0051] Compared to the shortcomings of existing technologies: the existing improved catalyst preparation process is cumbersome, the process parameters are complex, the reaction conditions are harsh, the production energy consumption is high, and the preparation and reaction process is prone to generating three types of pollutants, which does not conform to the development trend of green and low-carbon chemical industry and is difficult to scale up green production. This patent innovatively simplifies the preparation process in a non-obvious way, establishing a standardized modular preparation process of homogeneous complexation-simultaneous co-precipitation-gradient crystallization-washing and drying-programmed calcination-optional reduction. The parameters are controllable and easily scaled up. The catalytic reaction conditions are mild, with the reaction temperature controlled at 150-200 ℃ and the hydrogen pressure at 2-6 MPa, eliminating the need for extreme high temperature, high pressure, and high hydrogen partial pressure, thus significantly reducing production energy consumption. The preparation process uses an alcohol-water system, controllable pH precipitation, and alternating alcohol-water washing, resulting in no large-scale emission of harmful additives, low waste generation, and low treatment costs. It meets the development requirements of green chemical and low-carbon chemical industries, enabling large-scale, green industrial production and overcoming the shortcomings of existing processes in terms of low industrialization and greening.

Claims

1. A non-noble metal catalyst based on the selective cleavage of the CO bond in the furan ring of furfural to produce 1,5-pentanediol, characterized in that, It comprises a first metal component, a second metal component, and an oxide support; The first metal component is selected from one or two of Co and Ni; The second metal component is selected from one or more of Mn, Sr, Ce, and Sn; The carrier metal component is selected from one or more of Zr, Al, Ti, Si, Mg, and Zn; Based on the total weight of the catalyst, the content of the first metal component oxide is 20 wt.% to 60 wt.%, the content of the second metal component oxide is 1 wt.% to 20 wt%, and the content of the oxide support is 20 wt.% to 70 wt%.

2. The non-noble metal catalyst for the selective cleavage of the CO bond in the furan ring to 1,5-pentanediol based on furfural as described in claim 1, characterized in that... The catalyst is a composite oxide formed by the co-precipitation of multiple metals, with the metal components dispersed at the atomic level and the surface having a controllable distribution of oxygen vacancies and basic sites.

3. The non-noble metal catalyst for the selective cleavage of the CO bond in the furan ring to 1,5-pentanediol based on furfural as described in claim 1, characterized in that... The catalyst can achieve tilted adsorption of furan reactants at the C2-end by regulating the surface oxygen vacancy concentration and basic site density, and directionally break the C2-O1 bond of the furan ring. The catalyst is prepared by a soft template coupled homogeneous coprecipitation-hydrothermal crystallization process, and can induce the spontaneous assembly of multiple metal ions under weakly alkaline conditions to form a layered hydroxide precursor with a hydrotalcite-like structure. Through precise control of gradient crystallization, the precursor exhibits a typical nanosheet stacked morphology; After calcination, the layered topology of the precursor is partially retained and transformed into a porous composite oxide structure similar to hydrotalcite. This not only enables atomic-level dispersion of metal components but also achieves precise control of surface oxygen vacancies and alkaline sites. The catalyst combines the structural advantages of high specific surface area and strong surface alkalinity of hydrotalcite materials with the performance of multi-metal synergistic catalysis.

4. A method for preparing a non-noble metal catalyst based on the selective cleavage of the CO bond in the furan ring of furfural to generate 1,5-pentanediol, characterized in that, It comprises a first metal component, a second metal component, and an oxide support; The first metal component is selected from one or two of Co and Ni; The second metal component is selected from one or more of Mn, Sr, Ce, and Sn; The carrier metal component is selected from one or more of Zr, Al, Ti, Si, Mg, and Zn; Based on the total weight of the catalyst, the content of the first metal component oxide is 20 wt.% to 60 wt.%, the content of the second metal component oxide is 1 wt.% to 20 wt%, and the content of the oxide support is 20 wt.% to 70 wt%. (1) Dissolve the structure-regulating additive in an alcohol-water mixed solvent, then add the first metal soluble salt, the second metal soluble salt and the carrier metal soluble salt, stir at room temperature for 30 min ~ 120 min to form a clear and transparent multi-metal complex homogeneous solution. (2) Slowly add an alkaline precipitant to the homogeneous solution of the multi-metal complex, control the pH of the system to 9.0~13.0, and stir at a constant temperature of 35℃~60℃ for 30 min~180 min to achieve simultaneous co-precipitation of all metal ions; (3) The precipitate is subjected to two-stage gradient crystallization: the first stage is static aging at 40 ℃~80 ℃ for 2 h~8 h, and the second stage is hydrothermal crystallization at 90 ℃~150 ℃ for 2 h~4 h; (4) The crystallized product was washed alternately with deionized water and ethanol until the filtrate was neutral and no NO3⁻ was detected, and then subjected to gradient drying. (5) The dried precursor was calcined in air under programmed heating and then naturally cooled to obtain a non-precious metal multi-component oxide catalyst.

5. The preparation method of the non-noble metal catalyst based on furfural for the selective cleavage of CO bonds in the furan ring to produce 1,5-pentanediol as described in claim 4, characterized in that... The structure-regulating additive is selected from one or more of glucose, CTAB, chitosan, and citric acid, and the amount added is 2 wt.% to 15 wt.% of the total mass of all metal salts.

6. The preparation method of the non-noble metal catalyst based on furfural for the selective cleavage of CO bonds in the furan ring to produce 1,5-pentanediol as described in claim 4, characterized in that... The first metal soluble salt, the second metal soluble salt, and the carrier metal soluble salt are all selected from one or more of nitrates, acetates, and chlorides; in the alcohol-water mixed solvent, the volume ratio of deionized water to anhydrous ethanol is 1:1 to 6:1; the alkaline precipitant is one or two of NaOH, Na2CO3, KOH, K2CO3, and ammonia.

7. The preparation method of the non-noble metal catalyst based on furfural for the selective cleavage of CO bonds in the furan ring to produce 1,5-pentanediol as described in claim 4, characterized in that... The gradient drying process involves first vacuum drying at 60 °C for 6-10 h, followed by forced-air drying at 100 °C for 2-8 h; the programmed temperature calcination process involves increasing the temperature to 350 °C-550 °C at a rate of 1 °C / min-3 °C / min, and holding at that temperature for 3-6 h. It also includes an optional reduction step: reducing the calcined catalyst at 300℃~500℃ for 1 h~5 h in a 30% V H2 / N2 mixed atmosphere.

8. The application of the non-noble metal catalyst based on furfural for selectively breaking the CO bond of the furan ring to generate 1,5-pentanediol as described in claims 1-3 in the hydrogenation of furfural to prepare 1,5-pentanediol.

9. A method for the selective cleavage of the CO bond in the furan ring of furfural to generate 1,5-pentanediol, characterized in that, The non-noble metal catalyst based on furfural for selectively breaking the CO bond of the furan ring to generate 1,5-pentanediol, as described in any one of claims 1-3, is used under the following reaction conditions: reaction temperature 150 ℃~200 ℃, hydrogen pressure 2 MPa~6 MPa, reaction time 2 h~10 h, and the reaction solvent is selected from ethanol, isopropanol, and water.

10. A non-noble metal catalyst for the selective cleavage of the CO bond in the furan ring to 1,5-pentanediol based on furfural, wherein the catalyst is any one of the following: Option 1: Ni-Ce / Al2O3 catalyst (additive: CTAB) (1) Mix 400 mL of deionized water with 100 mL of anhydrous ethanol, add 3.20 g of CTAB and stir to dissolve; add 58.20 g of nickel nitrate hexahydrate, 8.70 g of cerium nitrate hexahydrate, and 49.50 g of aluminum nitrate nonahydrate, stir for 90 min to form a transparent homogeneous complex solution; slowly add KOH alkaline solution dropwise with stirring until pH=9.8, and then add the solution at 50 °C. o Continue stirring for 120 min to complete co-precipitation; transfer the suspension to a hydrothermal reactor and pass it through a 65°C bath. o C aging for 8 hours, 95 o Hydrothermal crystallization at C for 4 h, the product was washed alternately with deionized water and ethanol until neutral, 60 o Vacuum drying at 100°C for 8 hours. o Drying at C for 3 hours with forced air; using 1.5 o C / min increased to 480 o Calcination at C for 5 h, followed by calcination at 350 °C in a 30% V H2 / N2 mixed atmosphere. o After C reduction for 3 h, a Ni / CeO2-Al2O3 catalyst was obtained, in which the mass fraction of NiO was 46.9%, the mass fraction of CeO2 was 10.8%, and the mass fraction of Al was 42.3%. Option 2: Co-Sr / MgO catalyst (additive: chitosan) (1) Mix 300 mL of deionized water with 100 mL of ethanol, add 1.20 g of chitosan to dissolve; add 43.5 g of cobalt nitrate, 5.8 g of strontium chloride hexahydrate, and 48.2 g of magnesium nitrate hexahydrate in sequence, stir for 90 min to form a transparent homogeneous complex solution; slowly add NaOH alkaline solution dropwise with stirring until pH=10.0, and then add the solution at 50 °C. o Continue stirring for 120 min to complete co-precipitation; transfer the suspension to a hydrothermal reactor and heat for 70 minutes. o Aging at C for 6 h, followed by hydrothermal crystallization at 100 °C for 3 h, the product was washed alternately with deionized water and ethanol until neutral, and then... o Vacuum drying at 100°C for 8 hours. o C-air drying for 3 hours; after drying, 500℃ o Calcination at C for 4 h, followed by calcination at 400 °C in a 30% VH2 / N2 mixed atmosphere. o C reduction for 3 h yielded a Co / SrO-MgO catalyst, wherein the mass fraction of CoO was 56%, the mass fraction of SrO was 11.3%, and the mass fraction of MgO was 32.7%. Option 3: Co-Sn / Al2O3 catalyst (additive: citric acid) (1) Mix 350 mL of water with 70 mL of ethanol, add 4.50 g of citric acid; add 41.30 g of cobalt nitrate hexahydrate, 5.20 g of tin chloride, and 50.10 g of magnesium nitrate nonahydrate, stir for 80 min to form a transparent homogeneous complex solution; slowly add ammonia water dropwise with stirring until pH=9.0, 55 o Stirring at C for 100 min for initial co-precipitation; then transfer the suspension to a hydrothermal reactor, first at 80°C. o C aging for 4 hours, then at 110 o C hydrothermal crystallization for 2 hours, followed by washing and drying at 550°C o Calcination at C for 3 h, then in a 30 vol.% H2 / N2 atmosphere at 380 °C o C reduction for 3 h yielded a Co-Sn / Al2O3 catalyst, wherein the mass fraction of CoO was 54.6%, the mass fraction of SnO2 was 15.4%, and the mass fraction of Al2O3 was 30.0%. Option 4: Co-Mn / ZrO2 catalyst (additive: glucose) (1) Catalyst preparation: 300 mL of deionized water and 100 mL of anhydrous ethanol were mixed, and 5.0 g of glucose was added and stirred until completely dissolved; 48.4 g of cobalt nitrate hexahydrate, 6.0 g of manganese nitrate hexahydrate, and 52.8 g of zirconium nitrate pentahydrate were added sequentially, and stirred at room temperature for 90 min to form a transparent homogeneous complex solution; a mixed alkaline solution of NaOH and Na2CO3 was slowly added dropwise under stirring until the pH of the system reached 10.0, and the solution was then stirred at 50 °C. o Continue stirring for 120 min to complete co-precipitation; transfer the suspension to a hydrothermal reactor and heat at 70°C. o Static aging at 100°C for 6 hours. o Hydrothermal crystallization at C for 3 h; the product was washed alternately with deionized water and ethanol until neutral, then at 60 °C. o Vacuum drying at 100°C for 8 hours. o C-air drying for 3 hours; under air atmosphere at 2 o C / min increased to 500 o Calcination at C for 4 h, followed by calcination at 350 °C in a 30% V H2 / N2 mixed atmosphere. o C reduction for 2 h yielded a Co / Mn2O3-ZrO2 composite oxide catalyst; wherein the mass fraction of CoO was 42.6%, the mass fraction of Mn2O3 was 5.6%, and the mass fraction of ZrO2 was 51.8%. Option 5: Ni-Mn / ZnO catalyst (additives: glucose + citric acid) (1) Mix 300 mL of water with 100 mL of ethanol, add 3.00 g of glucose and 2.00 g of citric acid; add 38.20 g of nickel nitrate hexahydrate, 6.00 g of manganese nitrate hexahydrate, and 47.60 g of zinc nitrate hexahydrate, stir for 90 min to form a transparent homogeneous complex solution; slowly add Na2CO3 alkaline solution dropwise while stirring until pH=9.5, 55 o Stirring at C for 100 min for initial co-precipitation; then transfer the suspension to a hydrothermal reactor, first at 80°C. o Age at C for 4 hours, then at 130 o C hydrothermal crystallization for 2 hours, 500 o Calcination at C for 4 h, and finally heated at 350 °C in a 30 vol.% H2 / N2 atmosphere. o After C reduction for 3 h, a Ni-Mn / ZnO catalyst was obtained, in which the mass fraction of NiO was 40.1%, the mass fraction of Mn2O3 was 6.7%, and the mass fraction of ZnO was 53.2%.

Images