A metal oxide supported boron and phosphorus co-doped multi-element alloy catalyst, a preparation method and application thereof

Abstract

This invention proposes a boron-phosphorus co-doped multi-element alloy catalyst supported on a metal oxide substrate, its preparation method, and its application. It belongs to the technical field of sodium borohydride hydrolysis hydrogen production materials. The method involves loading cobalt salts (such as cobalt chloride or cobalt nitrate), iron salts (such as ferric chloride or ferric nitrate), and hypophosphite (such as sodium hypophosphite) onto a support (such as γ-alumina or titanium dioxide) using an initial wet impregnation method. Sodium borohydride solution is added for chemical reduction, and boron is added for doping. After washing the reduction product, the catalyst is dried to obtain the supported boron-phosphorus co-doped multi-element alloy catalyst. When used as a sodium borohydride hydrolysis hydrogen production catalyst, it provides a maximum hydrogen production rate of 12729.78 mL·g under optimal conditions. cat ‑1 ·min ‑1 It produces 100% of the theoretical hydrogen yield and features good catalytic performance, simple preparation method, abundant raw materials, and low cost.

Description

Technical Field

[0001] This invention belongs to the technical field of sodium borohydride hydrolysis hydrogen production materials, and particularly relates to a metal oxide supported boron and phosphorus co-doped multi-element alloy catalyst, its preparation method and application. Background Technology

[0002] Hydrogen is a clean alternative to natural gas. Hydrogen is the most abundant chemical element, estimated to make up 75% of the universe's mass. However, hydrogen as a gas is extremely rare. Hydrogen can be produced from a variety of resources, such as natural gas, nuclear power, biogas, and renewable energy sources like solar and wind power. The challenge lies in how to utilize hydrogen on a large scale to fuel our homes and businesses.

[0003] Sodium borohydride, as a hydrogen storage material, can spontaneously react with water to produce high-purity hydrogen. However, its drawbacks include a slow reaction rate and a conversion rate of only 7-8%. Noble metal catalysts such as palladium, ruthenium, and platinum exhibit highly efficient catalytic performance for the hydrolysis of sodium borohydride to produce hydrogen, but their high cost makes them unsuitable for widespread application.

[0004] Chinese invention patent CN113171776A discloses a supported catalyst, its preparation method, and its application for hydrogen production via sodium borohydride hydrolysis. The key feature is that solid nickel serves as the support, and Co, Fe, and B are dispersed uniformly within the pores of the solid nickel through chemical forces generated during calcination, forming a stable nickel-supported CoFeB sodium borohydride hydrolysis hydrogen production catalyst. At 50°C, the hydrogen production rate reaches 11300-148000 mL·g. cat -1 ·min -1 However, the reaction conditions for this patent are quite demanding, which is not conducive to market application.

[0005] Chinese invention patent CN114713230A discloses a CoNiB composite material with a Co / Ni ratio of 3:1 supported by carboxylated CNTs, its preparation method, and its application. The composite material is prepared using carboxylated CNTs, cobalt chloride hexahydrate, nickel chloride hexahydrate, triethylamine, anhydrous ethanol, water, and sodium borohydride as raw materials, employing an in-situ reduction method with sodium borohydride under ice-water conditions. The hydrogen production rate achieved at 25°C reaches 6100-6500 mL·g. cat -1 ·min -1 However, CNTs are relatively expensive, resulting in high catalyst preparation costs.

[0006] Chinese invention patent CN114984961A discloses a FeCo-Ni ternary alloy catalyst for hydrogen production via the hydrolysis of borohydride and its preparation method. The FeCo-Ni ternary alloy catalyst is electroplated onto a support using a spray electrodeposition method, providing a simple preparation process for a supported catalyst used in the hydrolysis of sodium borohydride solution to produce hydrogen, along with its preparation method and applications. A hydrogen production rate of 245.65 mL·g was achieved at 40°C. cat -1 ·min -1 The hydrogen production rate is low, and the catalytic performance is average. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention proposes a metal oxide-supported boron-phosphorus co-doped multi-element alloy catalyst, its preparation method, and its application.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] One of the technical solutions of the present invention:

[0010] A metal oxide supported boron and phosphorus co-doped multi-element alloy catalyst, the multi-element alloy catalyst comprising a support and multi-element doped Co active sites supported on the support;

[0011] The multi-element alloy catalyst is a rough and irregular aggregate with an amorphous surface structure. Co is electron-rich and exists mainly in its elemental and oxidized states. Fe, B, and P are all electron-deficient and exist mainly in their oxidized states. Doping with P increases the surface roughness and pore size of the catalyst, while B and Fe increase the electron cloud density of Co. The synergistic effect of B, Fe, and P enhances the catalytic performance of the catalyst.

[0012] SEM analysis revealed that the supported catalyst of this invention has a rough and irregular aggregate structure. XRD characterization of the supported catalyst showed no obvious characteristic peaks, indicating an amorphous surface structure. The unique short-range ordered but long-range disordered structure of this amorphous catalyst enhances the catalytic activity of the Co active sites for the hydrolysis of sodium borohydride. XPS comparative analysis of Co-B / γ-Al₂O₃, Co-BP / γ-Al₂O₃, and Co-Fe-BP / γ-Al₂O₃ showed that Co is electron-rich and exists mainly in elemental and oxidized states; B, Fe, and P are all electron-deficient and exist mainly in oxidized states. The synergistic effect of Fe, B, and P increases the electron cloud density of Co, preventing its oxidation. Pore size analysis showed that P doping increases the surface roughness and pore size of the catalyst. Therefore, the synergistic effect of B, Fe, and P enables the boron-phosphorus co-doped multi-element alloy catalyst to exhibit high catalytic activity for the hydrolysis of sodium borohydride.

[0013] The second technical solution of the present invention:

[0014] A method for preparing a boron-phosphorus co-doped multi-element alloy catalyst supported on a metal oxide comprises the following steps:

[0015] Cobalt salts, iron salts, and hypophosphite were loaded onto a support using a wet impregnation method.

[0016] Sodium borohydride solution was added for chemical reduction, and the reduction product was washed and dried to obtain a metal oxide-supported boron and phosphorus co-doped multi-element alloy catalyst.

[0017] Preferably, the specific method for attaching cobalt salt, iron salt, and hypophosphite onto the carrier via initial wet impregnation is as follows:

[0018] Cobalt salt, iron salt, and hypophosphite were dissolved in water by ultrasonication, then a carrier was added and stirred.

[0019] The cobalt salt is cobalt chloride (CoCl2) or cobalt nitrate (Co(NO3)2); the iron salt is ferric chloride (FeCl3) or ferric nitrate (Fe(NO3)3); and the hypophosphite is sodium hypophosphite (NaH2PO2).

[0020] Preferably, the mass ratio of the cobalt salt, iron salt and hypophosphite is 6:(1-5):16, more preferably 6:3:16.

[0021] Preferably, the mass ratio of the cobalt salt to the carrier is 60:1.

[0022] Preferably, the stirring refers to stirring at 50°C for 1 hour.

[0023] Preferably, the ratio of the amount of sodium borohydride to the total amount of Co and Fe in the metal salt ions is NaBH4∶(Co+Fe)=4∶1, to ensure complete reduction of the metal salt ions.

[0024] Preferably, the chemical reduction takes 1 hour.

[0025] Preferably, the washing refers to washing three times alternately with deionized water and anhydrous ethanol.

[0026] Preferably, the drying temperature is 80°C and the drying time is 8 hours.

[0027] The third technical solution of the present invention:

[0028] A sodium borohydride hydrolysis hydrogen production material prepared from the above-mentioned metal oxide supported boron and phosphorus co-doped multi-element alloy catalyst.

[0029] The fourth technical solution of the present invention:

[0030] The aforementioned metal oxide-supported boron-phosphorus co-doped multi-element alloy catalyst, when used in the catalytic hydrolysis of sodium borohydride to produce hydrogen, provides a hydrogen production rate of 12729.78 mL·gcat under optimal conditions. -1 ·min -1 The hydrogen production is 100% of the theoretical value.

[0031] Compared with the patents mentioned in the background art, the Co-Fe-BP quaternary alloy catalyst of the present invention, due to the unique synergistic effect of Fe, B and P, enables the catalyst to have a better hydrogen production rate under milder conditions (30°C), and the hydrogen production rate is not affected by the type of cobalt salt, iron salt and support.

[0032] Compared with the prior art, the present invention has the following advantages and technical effects:

[0033] (1) The structure of the multi-element alloy catalyst of this invention is a rough and irregular aggregate. XRD characterization analysis of the supported catalyst showed no obvious characteristic peaks, and the surface is an amorphous structure. Due to the unique short-range ordered but long-range disordered structure of the amorphous structure, the catalytic activity of the Co active sites for the hydrolysis of sodium borohydride is enhanced. By comparing the analysis of Co-B / γ-Al2O3, Co-BP / γ-Al2O3, and Co-Fe-BP / γ-Al2O3 by XPS, it can be found that: Co is electron-rich and mainly exists in the elemental and oxidized states; B, Fe, and P are all electron-deficient and mainly exist in the oxidized state. The synergistic effect of Fe, B, and P increases the electron cloud density of Co, preventing Co from being oxidized and improving its performance.

[0034] (2) The preparation method of the multi-element alloy catalyst of the present invention is simple, low in cost, and has a wide range of raw material sources;

[0035] (3) The multi-element alloy catalyst of this invention has high catalytic performance and high catalytic activity for the hydrolysis reaction of sodium borohydride. When used to catalyze the hydrolysis of sodium borohydride to produce hydrogen, the hydrogen production rate provided at 30°C can reach 12729.78 mL·gcat. -1 ·min -1 The hydrogen production is 100% of the theoretical value. Attached Figure Description

[0036] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0037] Figure 1 The XRD patterns of the supported catalysts Co-Fe-BP / γ-Al2O3 with different Co:Fe ratios in Examples 1-5 are shown.

[0038] Figure 2 SEM images of Co-B / γ-Al2O3 (a) in Comparative Example 6, Co-BP / γ-Al2O3 (b) in Comparative Example 7, Co-Fe-B / γ-Al2O3 in Comparative Example 1, and the supported catalyst Co-Fe-BP / γ-Al2O3 (d) with Co:Fe = 6:3 in Example 3;

[0039] Figure 3 XPS spectrum of Co-B / γ-Al2O3 catalyst in Comparative Example 6;

[0040] Figure 4 The XPS spectrum of the Co-BP / γ-Al2O3 catalyst in Comparative Example 7 is shown below.

[0041] Figure 5 The XPS spectrum of the supported catalyst Co-Fe-BP / γ-Al2O3 with Co:Fe = 6:3 in Example 3 is shown.

[0042] Figure 6 The pore size distributions of Co-B / γ-Al2O3 (a) in Comparative Example 6, Co-BP / γ-Al2O3 (b) in Comparative Example 7, Co-Fe-B / γ-Al2O3 (c) in Comparative Example 8, and the supported catalyst Co-Fe-BP / γ-Al2O3 (d) with Co:Fe = 6:3 in Example 3 are shown.

[0043] Figure 7 The performance graphs for the supported catalyst Co-Fe-BP / γ-Al2O3 with different Co:Fe ratios in Examples 1-5 are shown. The test conditions were: NaBH4 concentration of 10 wt.%, NaOH concentration of 10 wt.%, and temperature of 30°C.

[0044] Figure 8 The graph shows the performance of the Co-Fe-BP / γ-Al2O3 catalyst in Example 3 at different NaOH concentrations (2wt%, 4wt%, 6wt%, 8wt%, 10wt%). The test conditions were: NaBH4 concentration of 10wt.% and temperature of 30℃.

[0045] Figure 9 The graph shows the performance of the Co-Fe-BP / γ-Al2O3 catalyst in Example 3 under different NaBH4 concentrations (2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 20wt%). The test conditions were: NaOH concentration of 2wt.% and temperature of 30℃. Detailed Implementation

[0046] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0047] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0048] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0049] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0050] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0051] All raw materials used in the embodiments of this invention were obtained through commercial purchase.

[0052] The technical solution of the present invention will be further illustrated by the following embodiments.

[0053] Example 1

[0054] A method for preparing a supported catalyst Co-Fe-BP / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0055] 1) Weigh 0.6g CoCl2·6H2O, 0.1g Fe(NO3)3·6H2O and 1.6g NaH2PO2·H2O and dissolve them in 100mL of deionized water to form dispersion system A (i.e., the Co:Fe ratio is 6:1);

[0056] 2) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0057] 3) Weigh 0.419g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0058] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0059] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried under vacuum at 80°C for 8 hours to obtain the supported catalyst Co-Fe-BP / γ-Al2O3.

[0060] The supported catalyst prepared above was used for the catalytic hydrolysis of sodium borohydride to produce hydrogen:

[0061] Using an alkaline sodium borohydride aqueous solution as the raw material, with NaBH4 and NaOH both at concentrations of 10 wt%, the raw material and the supported catalyst Co-Fe-BP / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 4299.12 mL·g. cat -1 ·min -1 (See details) Figure 7 ).

[0062] Example 2

[0063] A method for preparing a supported catalyst Co-Fe-BP / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0064] 1) Weigh 0.6g CoCl2·6H2O, 0.2g Fe(NO3)3·6H2O and 1.6g NaH2PO2·H2O and dissolve them in 100mL of deionized water to form dispersion system A (i.e., the Co:Fe ratio is 6:2);

[0065] 2) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0066] 3) Weigh 0.4565g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0067] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0068] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 8 hours to obtain the supported catalyst Co-Fe-BP / γ-Al2O3.

[0069] The supported catalyst prepared above was used for the catalytic hydrolysis of sodium borohydride to produce hydrogen:

[0070] Using an alkaline sodium borohydride aqueous solution as the raw material, with NaBH4 and NaOH both at concentrations of 10 wt%, the raw material and the supported catalyst Co-Fe-BP / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 5258.28 mL·g. cat -1 ·min -1 (See details) Figure 7 ).

[0071] Example 3

[0072] A method for preparing a supported catalyst Co-Fe-BP / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0073] 1) Weigh 0.6g CoCl2·6H2O, 0.3g Fe(NO3)3·6H2O and 1.6g NaH2PO2·H2O and dissolve them in 100mL of deionized water to form dispersion system A (i.e., the Co:Fe ratio is 6:3);

[0074] 2) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0075] 3) Weigh 0.494g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0076] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0077] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 8 hours to obtain the supported catalyst Co-Fe-BP / γ-Al2O3.

[0078] The supported catalyst prepared above was used for the catalytic hydrolysis of sodium borohydride to produce hydrogen:

[0079] Using an alkaline sodium borohydride aqueous solution as raw material, with a NaBH4 concentration of 4 wt% and a NaOH concentration of 2 wt%, the raw material and the supported catalyst Co-Fe-BP / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 12729.78 mL·g. cat -1 ·min -1 (See details) Figure 9 ).

[0080] Example 4

[0081] A method for preparing a supported catalyst Co-Fe-BP / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0082] 1) Weigh 0.6g CoCl2·6H2O, 0.4g Fe(NO3)3·6H2O and 1.6g NaH2PO2·H2O and dissolve them in 100mL of deionized water to form dispersion system A (i.e., the Co:Fe ratio is 6:4, by mass).

[0083] 1) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0084] 2) Weigh 0.5314g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0085] 3) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0086] 4) The black solid was washed three times with deionized water and anhydrous ethanol alternately, and then dried at 80°C for 8 hours to obtain the supported catalyst Co-Fe-BP / γ-Al2O3.

[0087] The supported catalyst prepared above was used for the catalytic hydrolysis of sodium borohydride to produce hydrogen:

[0088] Using an alkaline sodium borohydride aqueous solution as the raw material, with NaBH4 and NaOH both at concentrations of 10 wt%, the raw material and the supported catalyst Co-Fe-BP / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 5545.32 mL·g. cat -1 ·min -1 (See details) Figure 7 ).

[0089] Example 5

[0090] A method for preparing a supported catalyst Co-Fe-BP / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0091] 1) Weigh 0.6g CoCl2·6H2O, 0.5g Fe(NO3)3·6H2O and 1.6g NaH2PO2·H2O and dissolve them in 100mL of deionized water to form dispersion system A (i.e., the Co:Fe ratio is 6:5);

[0092] 2) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0093] 3) Weigh 0.5689g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0094] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0095] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 8 hours to obtain the supported catalyst Co-Fe-BP / γ-Al2O3.

[0096] The supported catalyst prepared above was used for the catalytic hydrolysis of sodium borohydride to produce hydrogen:

[0097] Using an alkaline sodium borohydride aqueous solution as a raw material, with NaBH4 and NaOH both at concentrations of 10 wt%, the raw material and the supported catalyst Co-Fe-BP / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 5016.3 mL·g. cat -1 ·min -1 (See details) Figure 7 ).

[0098] Example 6

[0099] A method for preparing a supported catalyst Co-Fe-BP / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0100] 1) Weigh 0.6g CoCl2·6H2O, 0.3g FeCl3·6H2O and 1.6g NaH2PO2·H2O and dissolve them in 100mL of deionized water to form dispersion system A (i.e., the Co:Fe ratio is 6:3);

[0101] 2) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0102] 3) Weigh 0.5495g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0103] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0104] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 8 hours to obtain the supported catalyst Co-Fe-BP / γ-Al2O3.

[0105] The supported catalyst prepared above was used for the catalytic hydrolysis of sodium borohydride to produce hydrogen:

[0106] Using an alkaline sodium borohydride aqueous solution as raw material, with a NaBH4 concentration of 4 wt% and a NaOH concentration of 2 wt%, the raw material and the supported catalyst Co-Fe-BP / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 8611.5 mL·g. cat -1 ·min -1 .

[0107] Example 7

[0108] A method for preparing a supported catalyst Co-Fe-BP / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0109] 1) Weigh 0.6g Co(NO3)2·6H2O, 0.3g Fe(NO3)3·6H2O and 1.6g NaH2PO2·H2O and dissolve them in 100mL of deionized water to form dispersion system A (i.e., the Co:Fe ratio is 6:3);

[0110] 2) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0111] 3) Weigh 0.4243g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0112] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0113] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 8 hours to obtain the supported catalyst Co-Fe-BP / γ-Al2O3.

[0114] The supported catalyst prepared above was used for the catalytic hydrolysis of sodium borohydride to produce hydrogen:

[0115] Using an alkaline sodium borohydride aqueous solution as raw material, with a NaBH4 concentration of 4 wt% and a NaOH concentration of 2 wt%, the raw material and the supported catalyst Co-Fe-BP / γ-Al₂O₃ were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 11481.66 mL·g. cat -1 ·min -1 .

[0116] Example 8

[0117] A method for preparing a Co-Fe-BP / TiO2 supported catalyst for hydrogen production by hydrolysis of sodium borohydride, the specific steps of which are as follows:

[0118] 1) Weigh 0.6g CoCl2·6H2O, 0.3g Fe(NO3)3·6H2O and 1.6g NaH2PO2·H2O and dissolve them in 100mL of deionized water to form dispersion system A (i.e., the Co:Fe ratio is 6:3);

[0119] 2) Weigh 0.01g TiO2 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0120] 3) Weigh 0.494g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0121] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0122] 5) The black solid was washed three times with deionized water and anhydrous ethanol alternately, and then dried at 80°C for 8 hours to obtain the supported catalyst Co-Fe-BP / TiO2.

[0123] The supported catalyst prepared above was used for the catalytic hydrolysis of sodium borohydride to produce hydrogen:

[0124] Using an alkaline sodium borohydride aqueous solution as raw material, with a NaBH4 concentration of 4 wt% and a NaOH concentration of 2 wt%, the raw material and the supported catalyst Co-Fe-BP / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. Its catalytic hydrogen production rate from sodium borohydride hydrolysis was 9611.15 mL·g. cat -1 ·min -1 .

[0125] Comparative Example 1

[0126] A method for preparing a supported catalyst Co-Ni-B / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0127] 1) Weigh 0.25g CoCl2·6H2O, 0.25g NiCl2·6H2O and 0.05g citric acid and dissolve them in 100mL of deionized water to form dispersion system A;

[0128] 2) Weigh 0.02g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0129] 3) Weigh 0.3182g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0130] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0131] 5) The black solid was washed three times with deionized water and anhydrous ethanol alternately, and then dried at 80°C for 10 h to obtain the supported catalyst Co-Ni-B / γ-Al2O3.

[0132] The catalyst prepared above was used to catalyze the hydrolysis of sodium borohydride to produce hydrogen:

[0133] Using an alkaline sodium borohydride aqueous solution as a raw material, with NaBH4 and NaOH each at a concentration of 10 wt%, the raw material and the supported catalyst Co-Ni-B / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 900.6 mL·g. cat -1 ·min -1 .

[0134] Comparative Example 2

[0135] A method for preparing a supported catalyst Co-Mn-B / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0136] 1) Weigh 0.25g CoCl2·6H2O, 0.25g Mn(NO3)2 and 0.05g citric acid and dissolve them in 100mL of deionized water to form dispersion system A;

[0137] 2) Weigh 0.02g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0138] 3) Weigh 0.3706 g of NaBH4 and dissolve it in 5 mL of deionized water to obtain a NaBH4 solution;

[0139] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0140] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 10 h to obtain the supported catalyst Co-Mn-B / γ-Al2O3.

[0141] The catalyst prepared above was used to catalyze the hydrolysis of sodium borohydride to produce hydrogen:

[0142] Using an alkaline sodium borohydride aqueous solution as raw material, with NaBH4 and NaOH each at concentrations of 10 wt%, the raw material and the supported catalyst Co-Mn-B / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 1652.88 mL·g. cat -1 ·min -1 .

[0143] Comparative Example 3

[0144] A method for preparing a supported catalyst Co-Ce-B / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0145] 1) Weigh 0.25g CoCl2·6H2O, 0.25g Ce(NO3)2·6H2O and 0.05g citric acid and dissolve them in 100mL of deionized water to form dispersion system A;

[0146] 2) Weigh 0.02g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0147] 3) Weigh 0.103g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0148] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0149] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 10 h to obtain the supported catalyst Co-Ce-B / γ-Al2O3.

[0150] The catalyst prepared above was used to catalyze the hydrolysis of sodium borohydride to produce hydrogen:

[0151] Using an alkaline sodium borohydride aqueous solution as raw material, with NaBH4 and NaOH each at a concentration of 10 wt%, the raw material and the supported catalyst Co-Ce-B / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. Its catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 1454.28 mL·g. cat -1 ·min -1.

[0152] Comparative Example 4

[0153] A method for preparing a supported catalyst Co-Ca-B / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0154] 1) Weigh 0.25g CoCl2·6H2O, 0.25g Ca(NO3)2·4H2O and 0.05g citric acid and dissolve them in 100mL of deionized water to form dispersion system A;

[0155] 2) Weigh 0.02g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0156] 3) Weigh 0.1761g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0157] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0158] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 10 h to obtain the supported catalyst Co-Ca-B / γ-Al2O3.

[0159] The catalyst prepared above was used to catalyze the hydrolysis of sodium borohydride to produce hydrogen:

[0160] Using an alkaline sodium borohydride aqueous solution as raw material, with NaBH4 and NaOH each at a concentration of 10 wt%, the raw material and the supported catalyst Co-Ca-B / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 1598.64 mL·g. cat -1 ·min -1 .

[0161] Comparative Example 5

[0162] A method for preparing a supported catalyst Co-Cu-B / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0163] 1) Weigh 0.25g CoCl2·6H2O, 0.25g CuCl2·2H2O and 0.05g citric acid and dissolve them in 100mL of deionized water to form dispersion system A;

[0164] 2) Weigh 0.02g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0165] 3) Weigh 0.2378g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0166] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0167] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 10 h to obtain the supported catalyst Co-Cu-B / γ-Al2O3.

[0168] The catalyst prepared above was used to catalyze the hydrolysis of sodium borohydride to produce hydrogen:

[0169] Using an alkaline sodium borohydride aqueous solution as raw material, with NaBH4 and NaOH each at a concentration of 10 wt%, the raw material and Co-Cu-B / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. Its catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 746.4 mL·g. cat -1 ·min -1 .

[0170] Comparative Example 6

[0171] A method for preparing a supported catalyst Co-B / γ-Al2O3 for hydrogen production by hydrolysis of sodium borohydride, the specific steps of which are as follows:

[0172] 1) Weigh 0.6g of CoCl2·6H2O and dissolve it in 100mL of deionized water to form dispersion system A;

[0173] 2) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0174] 3) Weigh 0.2496g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0175] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0176] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 10 h to obtain the supported catalyst Co-B / γ-Al2O3.

[0177] The catalyst prepared above was used to catalyze the hydrolysis of sodium borohydride to produce hydrogen:

[0178] Using an alkaline sodium borohydride aqueous solution as raw material, with a NaBH4 concentration of 4 wt% and a NaOH concentration of 2 wt.%, the raw material and Co-B / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. Its catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 2221.44 mL·g. cat -1 ·min -1 .

[0179] Comparative Example 7

[0180] A method for preparing a supported catalyst Co-BP / γ-Al2O3 for hydrogen production by hydrolysis of sodium borohydride, the specific steps of which are as follows:

[0181] 1) Weigh 0.6g CoCl2·6H2O and 1.6g NaH2PO·H2O and dissolve them in 100mL of deionized water to form dispersion system A;

[0182] 2) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0183] 3) Weigh 0.2496g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0184] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0185] 5) The black solid was washed three times with deionized water and anhydrous ethanol alternately, and then dried at 80°C for 10 h to obtain the supported catalyst Co-BP / γ-Al2O3.

[0186] The catalyst prepared above was used to catalyze the hydrolysis of sodium borohydride to produce hydrogen:

[0187] Using an alkaline sodium borohydride aqueous solution as raw material, with a NaBH4 concentration of 4 wt% and a NaOH concentration of 2 wt.%, the raw material and Co-BP / γ-Al2O3 were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. Its catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 4170.6 mL·g. cat -1 ·min -1 .

[0188] Comparative Example 8

[0189] A method for preparing a supported catalyst Co-Fe-B / γ-Al2O3 for hydrogen production by sodium borohydride hydrolysis, the specific steps of which are as follows:

[0190] 1) Weigh 0.6g CoCl2·6H2O and 0.3g Fe(NO3)3·6H2O and dissolve them in 100mL of deionized water to form dispersion system A;

[0191] 2) Weigh 0.01g of γ-Al2O3 and place it in dispersion system A, stir at 50℃ for 1h to form dispersion system B;

[0192] 3) Weigh 0.494g of NaBH4 and dissolve it in 5mL of deionized water to obtain a NaBH4 solution;

[0193] 4) Add NaBH4 solution dropwise to dispersion system B, react for 1 hour, and then centrifuge to obtain a black solid;

[0194] 5) The black solid was washed three times with deionized water and anhydrous ethanol, and then dried at 80°C for 10 h to obtain the supported catalyst Co-Fe-B / γ-Al2O3.

[0195] The catalyst prepared above was used to catalyze the hydrolysis of sodium borohydride to produce hydrogen:

[0196] Using an alkaline sodium borohydride aqueous solution as raw material, with NaBH4 at 4 wt.% and NaOH at 2 wt%, the raw material and the supported catalyst Co-Ni-B / γ-Al₂O₃ were placed in a reactor, and the temperature was kept constant at 30 °C. The catalyst was then tested. The catalytic hydrogen production rate from the hydrolysis of sodium borohydride was 2362.68 mL·g. cat -1 ·min -1 .

[0197] The XRD patterns of the supported catalysts Co-Fe-BP / γ-Al2O3 with different Co:Fe ratios in Examples 1-5 are shown in Figure 5. Figure 1 ,Depend on Figure 1 It can be seen that the prepared Co-Fe-BP / γ-Al2O3 catalyst has an amorphous structure.

[0198] Figure 2 The images show SEM images of the supported catalysts Co-B / γ-Al2O3 (a) in Comparative Example 6, Co-BP / γ-Al2O3 (b) in Comparative Example 7, Co-Fe-B / γ-Al2O3 in Comparative Example 1, and Co-Fe-BP / γ-Al2O3 (d) in Example 3, where Co:Fe = 6:3. Figure 2 It can be seen that the undoped Co-B / γ-Al2O3 and Co-BP / γ-Al2O3 catalysts have a smooth layered structure, while the doped Co-BP / γ-Al2O3 and Co-Fe-BP / γ-Al2O3 have similar structures, exhibiting rough particle aggregates. It can be seen that the addition of P can increase the surface roughness of the catalyst.

[0199] Figure 3 The XPS spectrum of the Co-B / γ-Al2O3 catalyst in Comparative Example 6 is shown below. Figure 3 It can be seen that Co mainly exists in the oxidized state and the CoB form. The peak at 777.9 eV is attributed to CoB 2p3 / 2, while the peaks at 780.96 eV and 796.82 eV are attributed to Co, respectively. 2+ 2p3 / 2 and Co 2+ 2p1 / 2.

[0200] Figure 4 The XPS spectrum of the Co-BP / γ-Al2O3 catalyst in Comparative Example 7 is shown below. Figure 4 It can be seen that Co mainly exists in the oxidized state and the CoB form. The peak at 777.99 eV is attributed to CoB 2p3 / 2, and the peaks at 781.33 eV and 797.24 eV are attributed to Co, respectively. 2+ 2p3 / 2 and Co 2+ 2p1 / 2. Compared with the Co-BP / γ-Al2O3 catalyst, the binding energy of Co shifts to higher binding energies, indicating that the electron cloud density of Co decreases.

[0201] Figure 5 The XPS spectrum of the supported catalyst Co-Fe-BP / γ-Al2O3 with Co:Fe = 6:3 in Example 3 is shown below. Figure 5 It can be seen that Co mainly exists in the oxidized state and the CoB form. The peak at 777.91 eV is attributed to CoB 2p3 / 2, and the peaks at 780.68 eV and 796.68 eV are attributed to Co, respectively. 2+ 2p3 / 2 and Co 2+ 2p1 / 2. Compared with Co-B / γ-Al2O3 and Co-BP / γ-Al2O3 catalysts, the binding energy of Co shifts to lower binding energies, indicating an increase in the electron cloud density of Co.

[0202] Figure 6The pore size distributions are shown for Co-B / γ-Al2O3 (a) in Comparative Example 6, Co-BP / γ-Al2O3 (b) in Comparative Example 7, Co-Fe-B / γ-Al2O3 (c) in Comparative Example 8, and the supported catalyst Co-Fe-BP / γ-Al2O3 (d) with a Co:Fe ratio of 6:3 in Example 3. It can be seen that the undoped Co-B / γ-Al2O3 and Co-Fe-B / γ-Al2O3 are mainly mesoporous structures; after doping with P, the pore size of the Co-BP / γ-Al2O3 and Co-Fe-BP / γ-Al2O3 catalysts increases, although they are still predominantly mesoporous, macroporous structures appear. Therefore, P doping can increase the pore size of the catalyst, which is beneficial for the adsorption of sodium borohydride molecules and increases the catalyst activity.

[0203] Figure 7 The performance graphs for the supported catalyst Co-Fe-BP / γ-Al2O3 with different Co:Fe ratios in Examples 1-5 are shown (reaction conditions: NaBH4 and NaOH concentrations are both 10 wt.%, temperature is 30℃). It can be seen that the performance of the Co-Fe-BP / γ-Al2O3 catalysts with different Co:Fe ratios exhibits a volcano-like curve, reaching a maximum value of 6218.4 mL·g when Co:Fe = 6:3. cat -1 ·min -1 .

[0204] Figure 8 The graph shows the performance of the Co-Fe-BP / γ-Al2O3 catalyst in Example 3 at different NaOH concentrations (2 wt%, 4 wt%, 6 wt%, 8 wt%, and 10 wt%). The test conditions were: NaBH4 concentration of 10 wt.% and temperature of 30°C. It can be seen that the Co-Fe-BP / γ-Al2O3 catalyst in Example 3 exhibits the highest performance at a NaOH concentration of 2 wt.%. Increasing the NaOH concentration slightly decreases the catalyst's performance, then it remains constant.

[0205] Figure 9 The graph shows the performance of the Co-Fe-BP / γ-Al2O3 catalyst in Example 3 at different NaBH4 concentrations (2wt%, 4wt%, 6wt%, 8wt%, 10wt%, and 20wt%). The test conditions were: NaOH concentration of 2wt.% and temperature of 30℃. It can be seen that the performance of the Co-Fe-BP / γ-Al2O3 catalyst in Example 3 exhibits a volcanic effect under different NaBH4 concentrations, reaching a maximum value of 12729.78 mL·g at a concentration of 4wt.%. cat -1 ·min -1 .

[0206] In conjunction with Examples 1-8 and Comparative Examples 1-8, the γ-Al₂O₃-supported Co-Fe-BP catalyst exhibits significantly improved catalytic performance compared to monometallic borides, Co-Ni bimetallic borides, Co-Mn bimetallic borides, Co-Ce bimetallic borides, Co-Ca bimetallic borides, and Co-Cu bimetallic borides. This is because Co, Fe, B, and P exhibit a synergistic effect in the catalytic hydrolysis of sodium borohydride. The addition of P increases the surface roughness and pore size of the catalyst, thereby increasing the number of active sites; the addition of Fe increases the electron cloud density of Co, thus enhancing the catalytic performance. Compared to Fe, other metals have weaker electron-donating abilities, resulting in smaller performance improvements.

[0207] In summary, the supported catalyst for hydrogen production by hydrolysis of sodium borohydride prepared by this invention has the advantages of simple preparation process, short preparation cycle, superior catalytic performance, abundant raw materials, and low cost, and can be used for large-scale production.

[0208] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing a boron-phosphorus co-doped multi-element alloy catalyst supported on a metal oxide, characterized in that, Includes the following steps: Cobalt salt, iron salt and hypophosphite are loaded onto a support by a wet impregnation method, wherein the mass ratio of cobalt salt, iron salt and hypophosphite is 6:(1~5):16 and the mass ratio of cobalt salt to support is 60:

1. Sodium borohydride solution was added for chemical reduction. The reduction product was washed and dried to obtain a metal oxide-supported boron and phosphorus co-doped multi-element alloy catalyst. The chemical reduction time was 1 hour. The ratio of the amount of sodium borohydride to the total amount of Co and Fe in the metal salt ions is NaBH4∶(Co+Fe)=4∶1.

2. The method for preparing a metal oxide-supported boron and phosphorus co-doped multi-element alloy catalyst according to claim 1, characterized in that, The specific method for loading cobalt salts, iron salts, and hypophosphite onto the carrier via initial wet impregnation is as follows: Cobalt salt, iron salt, and hypophosphite were dissolved in water by ultrasonication, then a carrier was added and stirred. The cobalt salt is cobalt chloride or cobalt nitrate; the iron salt is ferric chloride or ferric nitrate; and the hypophosphite is sodium hypophosphite.

3. The method for preparing a metal oxide-supported boron and phosphorus co-doped multi-element alloy catalyst according to claim 2, characterized in that, The stirring refers to stirring at 50°C for 1 hour.

4. A sodium borohydride hydrolysis hydrogen production material, characterized in that, The catalyst is prepared by the preparation method described in any one of claims 1 to 3.

5. The application of the metal oxide-supported boron and phosphorus co-doped multi-element alloy catalyst prepared by the preparation method according to any one of claims 1 to 3 in the catalytic hydrolysis of sodium borohydride to produce hydrogen.

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