Carbon-doped tin dioxide loaded platinum-copper-nickel / cobalt catalyst as well as preparation method and application thereof
By preparing carbon-doped tin dioxide-supported platinum-copper-nickel/cobalt catalysts, the problems of insufficient stability and activation capacity of the catalysts during the hydrolysis of ammonia borane were solved, achieving efficient hydrogen release and high catalyst utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JILIN UNIVERSITY
- Filing Date
- 2026-03-11
- Publication Date
- 2026-05-19
AI Technical Summary
Existing catalysts suffer from poor stability and insufficient activation capacity during the hydrolysis of ammonia borane, making it difficult to achieve efficient hydrogen release. Furthermore, the scarcity of precious metals limits their large-scale application.
A single-atom platinum, copper, and nickel/cobalt catalyst was prepared by using carbon-doped tin dioxide supported on a hydrothermal reaction and a stepwise impregnation reduction method to ensure uniform metal dispersion. The carbon-doped tin dioxide support was combined to improve catalytic activity.
Highly efficient hydrogen production from ammonia borane hydrolysis was achieved. The catalyst maintained high activity and stability at high temperatures, significantly improving hydrogen release efficiency and bringing platinum utilization close to the theoretical limit.
Smart Images
Figure CN122057534A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalysis technology, specifically relating to a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst, its preparation method, and its application. Background Technology
[0002] The burning of fossil fuels has led to a shortage of non-renewable resources and global warming, making the development of clean and pollution-free renewable resources an urgent priority. Hydrogen energy, as a clean, pollution-free, high-energy-density, and sustainable energy source, is considered one of the most promising energy carriers for meeting the growing demand for clean energy. However, implementation barriers remain regarding the controlled release of sustainable hydrogen production and storage media, a key challenge that must be overcome to achieve a hydrogen economy. Ammonia borane, as a solid hydrogen storage material, is non-toxic, low-cost, lightweight, and possesses a high hydrogen storage capacity (19.6 wt%), thus exhibiting significant advantages in the hydrogen energy field. Reaction kinetics fundamentally depend on the catalyst-mediated activation of BH and OH bonds; therefore, the rational design of heterogeneous catalysts is crucial for optimizing hydrogen release efficiency.
[0003] While noble metals (Pt, Ru) exhibit excellent activity for the hydrolysis of ammonia borane (AB hydrolysis), their scarcity necessitates atomic-level dispersion to maximize catalytic efficiency. Unlike traditional metal nanoparticles, single-atom site catalysts (SASCs) achieve maximum metal dispersion and atom utilization efficiency, making them the most promising materials. SACs address this issue through near-theoretical metal utilization and diverse single-atom geometries, but stabilizing isolated atoms under hydrolysis conditions remains challenging. Furthermore, the gas-liquid-solid three-phase nature of AB hydrolysis places stringent requirements on catalyst wettability; optimal hydrogen evolution requires a hydrophilic surface to promote water activation while maintaining anaerobic properties for rapid separation of gaseous products. Summary of the Invention
[0004] In view of this, the present invention provides a carbon-doped tin dioxide supported platinum-copper-nickel / cobalt catalyst, its preparation method and its application. The catalyst provided by the present invention has high catalytic activity for the hydrolysis of ammonia borane to produce hydrogen.
[0005] This invention first involves a hydrothermal reaction of a carbon source, a tin source, and water to obtain a carbon-doped tin dioxide support precursor. The precursor is then calcined at different temperatures to obtain a carbon-doped tin dioxide support. Next, platinum, copper, and nickel / cobalt are loaded onto the support via a stepwise impregnation reduction method. The oxidized platinum, copper, and nickel / cobalt are then reduced to single atoms using a reducing agent, resulting in a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst. The preparation method provided by this invention is simple and easy to operate. In this invention, the single-atom platinum exhibits high activity, and the carbon-doped tin dioxide support has high binding performance with water and facilitates hydrogen desorption; therefore, the catalyst possesses high catalytic activity.
[0006] The present invention discloses a carbon-doped tin dioxide supported platinum-copper-nickel / cobalt catalyst, which consists of a carbon-doped tin dioxide support and supported atomically dispersed metallic platinum, metallic copper, and metallic nickel / cobalt.
[0007] Preferably, the loaded platinum, copper, and nickel / cobalt metals are atomically uniformly dispersed on the substrate surface.
[0008] Preferably, the mass ratio of the single-atom platinum, single-atom copper, single-atom nickel / cobalt to the carbon-doped tin dioxide support is 0.0024~0.0035:0.015~0.04:0.015~0.04:1.
[0009] The present invention also provides a method for preparing the above-mentioned carbon-doped tin dioxide supported platinum-copper-nickel / cobalt catalyst, the steps of which are as follows:
[0010] (1) After mixing and stirring carbon source, tin source and deionized water for a certain period of time, hydrothermal reaction is carried out. After cooling, centrifugation is performed. The solid obtained by centrifugation is washed with deionized water and ethanol until neutral and then dried to obtain carbon-doped tin dioxide support precursor.
[0011] (2) The carbon-doped tin dioxide support precursor obtained in step (1) is calcined to obtain a carbon-doped tin dioxide support.
[0012] (3) Add carbon-doped tin dioxide support to deionized water and prepare tin dioxide support suspension by ultrasonication. Add soluble platinum source to deionized water to prepare platinum source solution. Add soluble copper source and soluble nickel source to deionized water to prepare copper source solution and nickel source solution, respectively.
[0013] (4) Mix the copper source solution, nickel source solution and carbon-doped tin dioxide support suspension for a certain time and add reducing agent solution for reduction. Then add platinum source solution, mix and stir for a certain time and add reducing agent solution for reduction. Wash the solid obtained by solid-liquid separation with water until neutral and dry to obtain carbon-doped tin dioxide supported platinum-copper-nickel / cobalt catalyst.
[0014] Preferably, the hydrothermal reaction temperature in step (1) is 170~190℃, the hydrothermal reaction time is 3~5h, and the hydrothermal reaction is carried out in a reaction vessel lined with polytetrafluoroethylene.
[0015] In step (1), the temperature is cooled to 20~35℃, centrifuged at 8000~12000r / min for 8~15min, and then dried at 70~90℃ for 10~15h.
[0016] In step (1), the mass ratio of carbon source to tin source is 3~5:1, the concentration of tin source in water is 0.1~0.2g / mL, the stirring temperature is 20~30℃, the stirring speed is 550~700r / min, and the stirring time is 0.75~12h.
[0017] In step (1), the carbon source is one of glucose, sucrose, or fructose, and the tin source is one of sodium stannate, potassium stannate, tin sulfate, or tin tetrachloride.
[0018] In step (2), the calcination temperature is 200~400℃ and the calcination time is 1~12h;
[0019] In step (3), the mass ratio of deionized water to carbon-doped tin dioxide support precursor is 180~220:1;
[0020] In step (3), the reducing agent is sodium borohydride, the platinum source is platinum nitrate, the copper source is copper nitrate, the nickel source is nickel nitrate, and the cobalt source is cobalt nitrate;
[0021] In step (4), the mass ratio of single-atom platinum, single-atom copper, single-atom nickel / cobalt in the platinum source, copper source, and nickel / cobalt source to the carbon-doped tin dioxide support is 0.0024~0.0035:0.015~0.04:0.015~0.04:1;
[0022] In step (4), the stirring speed is 550~700 r / min and the stirring time is 45 min~12 h; the concentration of the reducing agent solution is 2~5 mol / L; the solid-liquid separation is carried out by centrifugation or filtration, the centrifugation speed is 8000~10000 r / min and the centrifugation time is 5~15 min; the filtration is carried out by a vacuum filter and a 0.22 micron filter membrane; the drying temperature is 60~90℃ and the drying time is 10~15 h.
[0023] This invention also provides the application of the above-mentioned carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst in the hydrolysis of ammonia borane to produce hydrogen. In the hydrolysis of ammonia borane to produce hydrogen, the ratio of reactants to catalyst is 1 mmol: 10~100 mg, preferably 1 mmol: 10~65 mg. Attached Figure Description
[0024] Figure 1 The XRD patterns of the catalysts prepared in Example 1 and Comparative Example 5 are shown below.
[0025] Figure 2 Thermogravimetric curves of the catalysts prepared in Example 1 and Comparative Example 5 are shown.
[0026] Figure 3 Fourier transform infrared spectra of the catalysts prepared in Example 1 and Comparative Example 5;
[0027] Figure 4 TEM image of the catalyst prepared in Example 1;
[0028] Figure 5 The image shows a TEM image of the catalyst prepared in Comparative Example 1.
[0029] Figure 6 The catalytic performance curves of the catalysts prepared in Example 1 and Comparative Example 5 for the hydrolysis of ammonia borane are shown.
[0030] Figure 7 This is a bar chart comparing the catalytic performance of the catalyst obtained in Example 1 under cyclic catalysis.
[0031] Figure 8 The XRD patterns of the catalysts prepared in Example 2 and Comparative Example 6 are shown below.
[0032] Figure 9 The catalytic performance curves of the catalysts prepared in Example 2 and Comparative Example 6 for the hydrolysis of ammonia borane are shown.
[0033] Figure 10 The XRD patterns of the catalysts prepared in Examples 1, 3-6 are shown below.
[0034] Figure 11 The figures show the catalytic performance curves of the catalysts prepared in Examples 3-6 for the hydrolysis of ammonia borane. Detailed Implementation
[0035] This invention provides a high-performance carbon-doped tin dioxide-supported platinum-copper-nickel ammonia-borane hydrogen production catalyst, comprising carbon-doped tin dioxide and supported atomically dispersed metallic platinum. In this invention, the platinum is exhibiting a single-atom dispersion. In this invention, the mass ratio of the single-atom platinum, single-atom copper, single-atom nickel / cobalt, and carbon-doped tin dioxide support is 0.0024~0.0035 : 0.015~0.04 : 0.015~0.04 : 1, preferably 0.0024~0.0026 : 0.02~0.03 : 0.02~0.03 : 1.
[0036] In this invention, the carrier preferably comprises tin dioxide and carbon-doped tin dioxide.
[0037] In this invention, unless otherwise specified, all raw materials are conventional commercially available products. Sodium stannate (NaSnO3·3H2O), platinum nitrate (Pt(NO3)2), copper nitrate (Cu(NO3)2·3H2O), and nickel nitrate (Ni(NO3)2·6H2O) used in the examples were purchased from Shanghai Maclean Biochemical Co., Ltd., sodium borohydride (NaBH4) was purchased from Sinopharm Chemical Reagent Co., Ltd., and glucose (C6H4) was purchased from Sinopharm Chemical Reagent Co., Ltd. 12 O6 was purchased from Xilong Technology Co., Ltd., and the deionized water came from the Milli-Q integrated water purification system (Millipore, 18.2 MΩ·cm). -1 ).
[0038] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0039] Example 1
[0040] (1) 1.8g sodium stannate trihydrate, 5.8g glucose and 40mL deionized water were stirred at 25℃ and 650r / min for 1h until clear and transparent. Then the mixture was transferred to a stainless steel reactor with a polytetrafluoroethylene liner and subjected to a hydrothermal reaction at 180℃ for 4h. After cooling to 30℃, the mixture was centrifuged at 10000r / min for 10min. The solid obtained by centrifugation was washed with deionized water and ethanol until neutral and then dried at 80℃ for 12h to obtain carbon-doped tin dioxide support precursor.
[0041] (2) The above-mentioned carrier precursor was calcined in a muffle furnace at 300°C for 12 hours to obtain carbon-doped tin dioxide carrier (SnO2-C, product mass is 1.8g).
[0042] (3) Platinum nitrate, copper nitrate and nickel nitrate were added to deionized water to prepare platinum nitrate solution, copper nitrate solution and nickel nitrate solution with concentrations of 4.7 mg / mL, 12 mg / mL and 12 mg / mL respectively;
[0043] (4) 0.4 g of carbon-doped tin dioxide support was added to 80 mL of deionized water and sonicated for 25 min to obtain a support suspension; 1 mL of copper nitrate solution and 1 mL of nickel nitrate solution were added to the support suspension and stirred at 25 °C and 650 r / min for 2.5 h; then 1 mL of 4 M sodium borohydride solution was added and stirred at 650 r / min for 45 min for reduction; then 0.4 mL of platinum nitrate solution was added to the above solution and stirred at 550 r / min for 50 min; then 1 mL of 2 M sodium borohydride solution was added and stirred at 650 r / min for 12 h for reduction; the above solution was filtered, and the solid obtained by filtration was washed with deionized water until neutral and then dried at 60 °C for 12 h to obtain carbon-doped tin dioxide supported platinum copper nickel catalyst (PtCuNi / SnO2-C), with a product mass of 0.4 g. In this embodiment, the mass ratio of single-atom platinum, single-atom copper, single-atom nickel and carbon-doped tin dioxide support is 0.0024:0.0175:0.0179:1.
[0044] Example 2
[0045] (1) 1.8g sodium stannate trihydrate, 5.8g glucose and 40mL deionized water were stirred at 25℃ and 650r / min for 1h until clear and transparent. Then the mixture was transferred to a stainless steel reactor with a polytetrafluoroethylene liner and subjected to a hydrothermal reaction at 180℃ for 4h. After cooling to 30℃, the mixture was centrifuged at 10000r / min for 10min. The solid obtained by centrifugation was washed with deionized water and ethanol until neutral and then dried at 80℃ for 12h to obtain carbon-doped tin dioxide support precursor.
[0046] (2) The above-mentioned carrier precursor was calcined in a muffle furnace at 300°C for 12 hours to obtain carbon-doped tin dioxide carrier (SnO2-C, product mass is 1.8g).
[0047] (3) Platinum nitrate, copper nitrate and cobalt nitrate were added to deionized water to prepare platinum nitrate solution, copper nitrate solution and cobalt nitrate solution with concentrations of 4.7 mg / mL, 12 mg / mL and 12 mg / mL respectively;
[0048] (4) 0.4 g of carbon-doped tin dioxide support was added to 80 mL of deionized water and sonicated for 25 min to obtain a support suspension; 1 mL of copper nitrate solution and 1 mL of cobalt nitrate solution were added to the support suspension and stirred at 25 °C and 650 r / min for 2.5 h; then 1 mL of 4 M sodium borohydride solution was added and stirred at 650 r / min for 45 min for reduction; then 0.4 mL of platinum nitrate solution was added to the above solution and stirred at 550 r / min for 50 min; then 1 mL of 2 M sodium borohydride solution was added and stirred at 650 r / min for 12 h for reduction; the above solution was filtered, and the obtained solid was washed with deionized water until neutral and then dried at 60 °C for 12 h to obtain carbon-doped tin dioxide supported platinum copper cobalt catalyst (PtCuCo / SnO2-C), with a product mass of 0.4 g. In this embodiment, the mass ratio of single-atom platinum, single-atom copper, single-atom cobalt and carbon-doped tin dioxide support is 0.0025:0.0216:0.0208:1.
[0049] Comparative Example 1
[0050] (1) 1.8g sodium stannate trihydrate, 5.8g glucose and 40mL deionized water were stirred at 25℃ and 650r / min for 1h until clear and transparent. Then the mixture was transferred to a stainless steel reactor with a polytetrafluoroethylene liner and subjected to a hydrothermal reaction at 180℃ for 4h. After cooling to 30℃, the mixture was centrifuged at 10000r / min for 10min. The solid obtained by centrifugation was washed with deionized water and ethanol until neutral and then dried at 80℃ for 12h to obtain carbon-doped tin dioxide support precursor.
[0051] (2) The above-mentioned carrier precursor was calcined in a muffle furnace at 300°C for 12 hours to obtain carbon-doped tin dioxide carrier (SnO2-C, product mass is 1.8g).
[0052] (3) Prepare a 4.7 mg / mL platinum nitrate solution;
[0053] (4) 0.4 g of carbon-doped tin dioxide support was added to 80 mL of deionized water and sonicated for 25 min to obtain a support suspension; 0.4 mL of platinum nitrate solution was added to the above solution, and the mixture was stirred at 550 r / min for 50 min, then 1 mL of 2 M sodium borohydride solution was added, and the mixture was stirred at 650 r / min for 12 h for reduction; the above solution was filtered, and the resulting solid was washed with deionized water until neutral and then dried at 60 °C for 12 h to obtain a carbon-doped tin dioxide-supported platinum catalyst (Pt / SnO2-C), with a product mass of 0.4 g. In this comparative example, the mass ratio of single-atom platinum to carbon-doped tin dioxide support was 0.0026:1.
[0054] Comparative Example 2
[0055] (1) 1.8g sodium stannate trihydrate, 5.8g glucose and 40mL deionized water were stirred at 25℃ and 650r / min for 1h until clear and transparent. Then the mixture was transferred to a stainless steel reactor with a polytetrafluoroethylene liner and subjected to a hydrothermal reaction at 180℃ for 4h. After cooling to 30℃, the mixture was centrifuged at 10000r / min for 10min. The solid obtained by centrifugation was washed with deionized water and ethanol until neutral and then dried at 80℃ for 12h to obtain carbon-doped tin dioxide support precursor.
[0056] (2) The above-mentioned carrier precursor was calcined in a muffle furnace at 300°C for 12 hours to obtain carbon-doped tin dioxide carrier (SnO2-C, product mass is 1.8g).
[0057] (3) Prepare a 12 mg / mL copper nitrate solution;
[0058] (4) 0.4 g of carbon-doped tin dioxide support was added to 80 mL of deionized water and sonicated for 25 min to obtain a support suspension; 1 mL of copper nitrate solution was added to the above solution, and the mixture was stirred for 2.5 h at 25 °C and 650 r / min; then 1 mL of 2 M sodium borohydride solution was added, and the mixture was stirred for 12 h at 650 r / min; the above solution was filtered, and the resulting solid was washed with deionized water until neutral and then dried at 60 °C for 12 h to obtain carbon-doped tin dioxide supported copper catalyst (Cu / SnO2-C), with a product mass of 0.4 g. In this comparative example, the mass ratio of single-atom copper to carbon-doped tin dioxide support was 0.0202:1.
[0059] Comparative Example 3
[0060] (1) 1.8g sodium stannate trihydrate, 5.8g glucose and 40mL deionized water were stirred at 25℃ and 650r / min for 1h until clear and transparent. Then the mixture was transferred to a stainless steel reactor with a polytetrafluoroethylene liner and subjected to a hydrothermal reaction at 180℃ for 4h. After cooling to 30℃, the mixture was centrifuged at 10000r / min for 10min. The solid obtained by centrifugation was washed with deionized water and ethanol until neutral and then dried at 80℃ for 12h to obtain carbon-doped tin dioxide support precursor.
[0061] (2) The above-mentioned carrier precursor was calcined in a muffle furnace at 300°C for 12 hours to obtain carbon-doped tin dioxide carrier (SnO2-C, product mass is 1.8g).
[0062] (3) Prepare a 12 mg / mL nickel nitrate solution;
[0063] (4) 0.4 g of carbon-doped tin dioxide support was added to 80 mL of deionized water and sonicated for 25 min to obtain a support suspension; 1 mL of nickel nitrate solution was added to the above solution, and the mixture was stirred for 2.5 h at 25 °C and 650 r / min; then 1 mL of 2 M sodium borohydride solution was added, and the mixture was stirred for 12 h at 650 r / min; the above solution was filtered, and the resulting solid was washed with deionized water until neutral and then dried at 60 °C for 12 h to obtain carbon-doped tin dioxide supported nickel catalyst (Ni / SnO2-C), with a product mass of 0.4 g. In this comparative example, the mass ratio of single-atom nickel to carbon-doped tin dioxide support was 0.0179:1.
[0064] Comparative Example 4
[0065] (1) 1.8g sodium stannate trihydrate, 5.8g glucose and 40mL deionized water were stirred at 25℃ and 650r / min for 1h until clear and transparent. Then the mixture was transferred to a stainless steel reactor with a polytetrafluoroethylene liner and subjected to a hydrothermal reaction at 180℃ for 4h. After cooling to 30℃, the mixture was centrifuged at 10000r / min for 10min. The solid obtained by centrifugation was washed with deionized water and ethanol until neutral and then dried at 80℃ for 12h to obtain carbon-doped tin dioxide support precursor.
[0066] (2) The above-mentioned carrier precursor was calcined in a muffle furnace at 300°C for 12 hours to obtain carbon-doped tin dioxide carrier (SnO2-C, product mass is 1.8g).
[0067] (3) Prepare copper nitrate and nickel nitrate solutions of 12 mg / mL copper nitrate and 12 mg / mL nickel nitrate, respectively;
[0068] (4) 0.4 g of carbon-doped tin dioxide support was added to 80 mL of deionized water and sonicated for 25 min to obtain a support suspension. 1 mL of copper nitrate solution and 1 mL of nickel nitrate solution were added to the above suspension, and the mixture was stirred for 2.5 h at 25 °C and 650 r / min. Then, 1 mL of 4 M sodium borohydride solution was added, and the mixture was stirred at 650 r / min for 12 h. The above solution was filtered, and the resulting solid was washed with deionized water until neutral and then dried at 60 °C for 12 h to obtain a carbon-doped tin dioxide-supported copper-nickel catalyst (CuNi / SnO2-C). The mass of the product was 0.4 g. In this comparative example, the mass ratio of single-atom copper, single-atom nickel, and carbon-doped tin dioxide support was 0.0180:0.0200:1.
[0069] Comparative Example 5
[0070] (1) A carbon-doped tin dioxide support precursor was prepared according to the method of Example 1;
[0071] (2) The carbon-doped tin dioxide support precursor was calcined at 500°C for 1 h in a muffle furnace to obtain tin dioxide support (SnO2);
[0072] (3) A tin dioxide-supported platinum-copper-nickel catalyst (PtCuNi / SnO2) was prepared by loading metals according to the method of Example 1. The product mass was 0.4 g. In this comparative example, the mass ratio of single-atom platinum, single-atom copper, single-atom nickel and tin dioxide support was 0.0031:0.0179:0.0169:1.
[0073] Comparative Example 6
[0074] (1) A carbon-doped tin dioxide support precursor was prepared according to the method of Example 2;
[0075] (2) The carbon-doped tin dioxide support precursor was calcined at 500°C for 1 h in a muffle furnace to obtain tin dioxide support (SnO2);
[0076] (3) A tin dioxide-supported platinum-copper-cobalt catalyst (PtCuCo / SnO2) was prepared by loading metals according to the method of Example 1. The product mass was 0.4 g. In this comparative example, the mass ratio of single-atom platinum, single-atom copper, single-atom cobalt and tin dioxide support was 0.0035:0.0235:0.0264:1.
[0077] The catalysts prepared in Example 1 and Comparative Example 5 were subjected to XRD analysis, and the XRD spectra were obtained as follows: Figure 1 As shown. By Figure 1 It can be seen that the XRD spectra of the catalysts prepared in Example 1 and Comparative Example 5 do not have metal diffraction peaks, indicating that the metal supported in the catalysts prepared in the examples is very small and uniformly dispersed, and the corresponding diffraction peaks cannot be detected by XRD.
[0078] Thermogravimetric analysis was performed on the catalysts prepared in Example 1 and Comparative Example 5, and thermogravimetric curves were obtained, as shown in the figure. Figure 2 As shown. By Figure 2 It can be seen that the catalyst prepared in Example 1 still has a weight loss peak at temperatures above 300°C, indicating that the sample contains carbon species. The catalyst prepared in Comparative Example 5 only contains adsorbed water molecules (no weight loss peak at high temperature) and does not contain other species.
[0079] Fourier transform infrared (FTIR) detection was performed on the catalysts prepared in Example 1 and Comparative Example 5, and the Fourier transform infrared spectra were obtained, as shown below. Figure 3 As shown. By Figure 3It can be seen that the catalyst prepared in Example 1 contains the vibrational peak of CH bond (2880 cm⁻¹). -1 ~2980cm -1 This indicates that the sample contains carbon species; the catalyst prepared in Comparative Example 5 does not contain the vibrational peaks of CH bonds (2880~2980 cm⁻¹). -1 This indicates that the sample does not contain carbon species.
[0080] The catalysts prepared in Example 1 and Comparative Example 5 were examined by transmission electron microscopy (TEM) to obtain TEM images, as shown below. Figures 4-5 As shown, where Figure 4 These are TEM images of the catalyst prepared in Example 1 at different magnifications. Figure 5 TEM images of the catalyst prepared in Comparative Example 5 at different magnifications are shown below. Figure 4 As shown, the flower-like spheres in the image are carbon-doped tin dioxide. Because the contrast between the carrier and the metal is too weak, nanoparticles were not observed. Meanwhile... Figure 5 In the image, the flower-shaped spheres are tin dioxide, and the bright spots on them are platinum nanoparticles (copper and nickel have smaller molecular weights than tin in the support, so they are covered by the support in the dark). Figure 5 (a) The average particle size of the platinum nanoparticles was found to be 2.4 nm.
[0081] The samples obtained in Example 1 and Comparative Example 5 were used as catalysts to catalyze the hydrolysis of ammonia borane to produce hydrogen. The molar amount of ammonia borane reactant was 1 mmol; the solvent was water, 0.5 mL; the catalyst was a platinum molar amount / ammonia borane molar amount of 0.0008 / 1 (meaning the molar amount of Pt in PtCuNi / SnO2-C was 0.0008 / 1); the temperature was 25 °C; and the magnetic stirring speed was 650 r / min.
[0082] Based on the catalytic performance curves of hydrogen production from the hydrolysis of ammonia boronane in Example 1 and Comparative Example 5, as follows: Figure 6 As shown, the catalyst prepared in Example 1 exhibits an extremely high hydrogen production rate from the hydrolysis of ammonia borane (TOF = 1967 mol). H2 mol Pt -1 min -1 Its hydrogen production rate is approximately three times that of Comparative Example 5 (TOF = 694 mol). H2 mol Pt -1 min -1 ).
[0083] The sample obtained in Example 1 was used as a catalyst for the cyclic catalytic production of hydrogen from ammonia borane. The molar amount of ammonia borane reactant was 1 mmol; the solvent was water, 0.5 mL; the catalyst was platinum molar amount / ammonia borane molar amount = 0.0008 / 1; the temperature was 25 °C; and the magnetic stirring speed was 650 r / min.
[0084] like Figure 7 As shown, the catalyst PtCuNi / SnO2-C prepared in Example 1 exhibits excellent cycling stability in the cycling stability test of ammonia borane, with a catalytic performance loss of <1% in five consecutive runs.
[0085] The catalysts prepared in Example 2 and Comparative Example 6 were subjected to XRD analysis, and the XRD spectra were obtained as follows: Figure 8 As shown. By Figure 8 It can be seen that the XRD spectra of the catalysts prepared in Example 2 and Comparative Example 6 do not have metal diffraction peaks, indicating that the metal supported in the catalysts prepared in the examples is very small and uniformly dispersed, and the corresponding diffraction peaks cannot be detected by XRD.
[0086] Based on the catalytic performance curves of hydrogen production from the hydrolysis of ammonia borane in Example 2 and Comparative Example 6, as follows: Figure 9 As shown, the catalyst prepared in Example 2 exhibits an extremely high hydrogen production rate from the hydrolysis of ammonia borane (TOF = 1634 mol). H2 mol Pt -1 min -1 Its hydrogen production rate is approximately 2.5 times that of Comparative Example 6 (TOF = 650 mol). H2 mol Pt -1 min -1 ).
[0087] The catalysts prepared in Examples 1, 3-6 were subjected to XRD analysis, and the XRD spectra were obtained, as shown below. Figure 10 As shown. By Figure 10 It can be seen that the XRD patterns of the catalysts prepared in Examples 1, 3-6 do not have metal diffraction peaks, indicating that the metal supported in the catalysts prepared in the examples is very small and uniformly dispersed, and the corresponding diffraction peaks cannot be detected by XRD.
[0088] like Figure 11 It can be seen that the hydrogen production rate of CuNi / SnO2-C (comparative Example 4 product) is similar to that of Pt / SnO2-C (comparative Example 1 product) (TOF=155 mol). H2 mol Pt -1 min -1The results were close to those of Cu / SnO2-C (comparative Example 2 product) and Ni / SnO2-C (comparative Example 3 product), while Cu / SnO2-C produced almost no hydrogen.
[0089] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.
Claims
1. A method for preparing a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst, comprising the following steps: (1) After mixing and stirring carbon source, tin source and deionized water for a certain period of time, hydrothermal reaction is carried out. After cooling, centrifugation is performed. The solid obtained by centrifugation is washed with deionized water and ethanol until neutral and then dried to obtain carbon-doped tin dioxide support precursor. (2) The carbon-doped tin dioxide support precursor obtained in step (1) is calcined to obtain a carbon-doped tin dioxide support. (3) Add carbon-doped tin dioxide support to deionized water and prepare tin dioxide support suspension by ultrasonication. Add soluble platinum source to deionized water to prepare platinum source solution. Add soluble copper source and soluble nickel source to deionized water to prepare copper source solution and nickel source solution, respectively. (4) Mix the copper source solution, nickel source solution and carbon-doped tin dioxide support suspension, stir for a certain time, add reducing agent solution for reduction, and then add platinum source solution. The mixture was stirred for a certain period of time and a reducing agent solution was added for reduction. The solid obtained from solid-liquid separation was washed with water until neutral and then dried to obtain a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst.
2. The method for preparing a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst as described in claim 1, characterized in that: The hydrothermal reaction temperature in step (1) is 170~190℃, the hydrothermal reaction time is 3~5h, and the hydrothermal reaction is carried out in a reaction vessel lined with polytetrafluoroethylene; it is cooled to 20~35℃, centrifuged at 8000~12000r / min for 8~15min, and then dried at 70~90℃ for 10~15h.
3. The method for preparing a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst as described in claim 1, characterized in that: In step (1), the mass ratio of carbon source to tin source is 3~5:1, the concentration of tin source in water is 0.1~0.2g / mL, the stirring temperature is 20~30℃, the stirring speed is 550~700r / min, and the stirring time is 0.75~12h.
4. The method for preparing a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst as described in claim 1, characterized in that: In step (1), the carbon source is one of glucose, sucrose, or fructose, and the tin source is one of sodium stannate, potassium stannate, tin sulfate, or tin tetrachloride.
5. The method for preparing a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst as described in claim 1, characterized in that: In step (2), the calcination temperature is 200~400℃ and the calcination time is 1~12h.
6. The method for preparing a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst as described in claim 1, characterized in that: In step (3), the mass ratio of deionized water to carbon-doped tin dioxide carrier precursor is 180~220:
1.
7. The method for preparing a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst as described in claim 1, characterized in that: In step (3), the reducing agent is sodium borohydride, the platinum source is platinum nitrate, the copper source is copper nitrate, the nickel source is nickel nitrate, and the cobalt source is cobalt nitrate; the mass ratio of single-atom platinum, single-atom copper, single-atom nickel / cobalt in the platinum source, copper source, and nickel / cobalt source to the carbon-doped tin dioxide support is 0.0024~0.0035:0.015~0.04:0.015~0.04:
1.
8. The method for preparing a carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst as described in claim 1, characterized in that: In step (4), the stirring speed is 550~700 r / min and the stirring time is 45 min~12 h; the concentration of the reducing agent solution is 2~5 mol / L; the solid-liquid separation is carried out by centrifugation or filtration, the centrifugation speed is 8000~10000 r / min and the centrifugation time is 5~15 min; the filtration is carried out by a vacuum filter and a 0.22 micron filter membrane; the drying temperature is 60~90℃ and the drying time is 10~15 h.
9. A carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 8.
10. The application of the carbon-doped tin dioxide-supported platinum-copper-nickel / cobalt catalyst according to claim 9 in the hydrolysis of ammonia borane to produce hydrogen.