Methanoic acid decomposition hydrogen production catalyst with photoresponse characteristic and preparation method thereof

Abstract

The invention relates to the technical field of new energy hydrogen storage and catalytic hydrogen production, in particular to a formic acid decomposition hydrogen production catalyst with a light response characteristic and a preparation method thereof. In order to achieve the purposes of broad spectrum response and efficient hydrogen production, the catalyst design adopts an N-doped modified semiconductor catalyst CeO2 method, the spectral response range of the catalyst CeO2 in visible light is widened, and the loaded metal Pd not only serves as an active catalytic metal for efficiently catalyzing formic acid decomposition to produce hydrogen, but also plays a role in further modifying the semiconductor catalyst CeO2, so that the catalytic activity of the catalyst CeO2 is improved. The photoresponse performance and the photocatalytic efficiency of CeO2 are further improved, and the selectivity of catalyzing formic acid to produce hydrogen is 100%.

Description

Technical Field

[0001] The present invention relates to the technical fields of new energy hydrogen storage and catalytic hydrogen production, and specifically relates to a formic acid decomposition hydrogen production catalyst with light response characteristics and a preparation method thereof. Background Art

[0002] Hydrogen energy has the advantages of being pollution-free, renewable, and having a wide range of sources. Its unit energy density is high, and the end product of utilization is water, which is considered to be one of the most ideal energy sources. In order to promote the development of the hydrogen energy industry, a series of support policies have been introduced in China. Therefore, to promote the application of the hydrogen energy industry, it is necessary to solve related technical problems such as hydrogen production and storage in the process of hydrogen energy utilization. Solid / liquid chemical materials (such as formic acid, methane, etc.) hydrogen storage technology is most promising to solve the problems of hydrogen storage and transportation in the process of hydrogen energy utilization, such as formic acid, methane, etc., but there are currently problems such as slow hydrogen production reaction kinetics of hydrogen storage materials.

[0003] Formic acid (HCOOH) has the advantages of a wide range of sources, stable chemical properties, being liquid at room temperature and normal pressure, and having a high hydrogen mass fraction (4.8 wt%). In addition, formic acid is not easy to burn, is safe and convenient for transportation and storage, and formic acid belongs to class C. Formic acid has obvious safety advantages in terms of stacking standards and total amount, etc., and is a very potential chemical hydrogen storage material. Formic acid can dehydrogenate and release H2 under the action of a catalyst at room temperature and normal pressure. Formic acid hydrogen production technology shows important application potential in fields such as distributed energy, industrial production, and agricultural innovation. During the catalytic formic acid hydrogen production reaction, formic acid first adsorbs onto the catalyst surface, the O-H bond breaks, generating HCOO - and H + ; the activation of HCOO - promotes the breakage of the C-H bond, generating CO2 and releasing H + ; H + combines with the H + generated in the previous step to form H2, completing dehydrogenation. However, the formic acid dehydrogenation reaction is usually affected by the competition of the dehydration reaction path, generating by-products such as H2O and CO. Therefore, the design and preparation of highly active and highly selective catalysts are one of the key problems that need to be solved urgently in formic acid hydrogen production technology.

[0004] Cerium dioxide (CeO2) is a good semiconductor photocatalytic active material, which has the advantages of high stability, low toxicity, low price, and being convenient for large-scale synthesis. CeO2 has a relatively wide band gap (about 3.2 eV), and its band gap value can be regulated by doping heteroelements. Due to its good redox performance and stability, cerium dioxide photocatalytic technology has been gradually widely applied in fields such as environmental governance, energy conversion, and organic synthesis. Summary of the Invention

[0005] To overcome the deficiencies in the background art, the object of the present invention is to provide a formic acid decomposition hydrogen production catalyst with light response characteristics and a preparation method thereof. This catalyst can catalyze the decomposition of formic acid to produce hydrogen in the absence of light, and under light conditions, it can quickly respond to light, generate a photo-coupled synergistic catalytic effect, strengthen the formic acid decomposition hydrogen production reaction, and obtain high formic acid hydrogen production performance. The preparation method of this catalyst is simple and suitable for large-scale and batch production.

[0006] For a formic acid decomposition hydrogen production catalyst with light response characteristics of the present invention, to achieve the purpose of wide-spectrum response and high-efficiency hydrogen production, the catalyst is designed by using the method of N-doped modified semiconductor catalyst CeO2 to improve the spectral response range of the catalyst CeO2 in the visible light. Loading metal Pd not only serves as an active catalytic metal for efficiently catalyzing the decomposition of formic acid to produce hydrogen, but also plays a role in further modifying the semiconductor catalyst CeO2, further enhancing the light response performance and photocatalytic efficiency of CeO2.

[0007] The preparation method of a formic acid decomposition hydrogen production catalyst with light response characteristics provided by the present invention specifically includes the following steps: (1) Dissolve Ce(NO3)3•6H2O in deionized water to obtain a Ce(NO3)3 solution, then slowly drip the NaOH aqueous solution into the above Ce(NO3)3 solution, perform magnetic stirring during the dripping process, then add the CO(NH2)2 aqueous solution, and then perform magnetic stirring to make it evenly mixed. Transfer the obtained mixed solution to a high-pressure reaction kettle, and then place the high-pressure reaction kettle in a constant temperature oven at 180°C to 200°C for reaction, and the reaction time is not less than 24h; after the reaction is completed, cool to room temperature, centrifuge the reaction solution, discard the supernatant, wash and dry the precipitate, and calcine it at a certain temperature to obtain N-doped CeO2, denoted as N-CeO2; (2) Ultrasonically disperse N-CeO2 in deionized water to form an N-CeO2 suspension, add 3-aminopropyltriethoxysilane (APTS) to the above suspension and stir, then add PdCl2 to the above suspension, fully stir to obtain a dispersion, and then slowly drip the newly prepared NaBH4 aqueous solution into the above dispersion, stir vigorously while adding, and the reaction time is not less than 30min. After the reaction is completed, centrifuge, wash, dry, and grind the obtained product to obtain a formic acid decomposition hydrogen production catalyst with light response characteristics, denoted as PdN-CeO2.

[0008] Further, in step (1), the precipitate is washed 3 times with deionized water and absolute ethanol respectively; Further, in step (1), it is calcined at 350°C to 550°C for 4 - 6h; Furthermore, in step (1), the molar concentration of the Ce(NO3)3 solution is 1-5 mol / L, the molar concentration of the NaOH aqueous solution is 1 mol / L; and the concentration of the CO(NH2)2 aqueous solution is 0.5-1.5 mol / L.

[0009] Furthermore, in step (1), the volume ratio of the CO(NH2)2 aqueous solution to the Ce(NO3)3 solution is (1-3):20; Furthermore, in step (2), N-CeO2 is ultrasonically dispersed in deionized water to form an N-CeO2 suspension with a concentration of 0.1-0.4 g / mL; Furthermore, 0.5-3.5 mL of APTS was added to the N-CeO2 suspension in step (2) and stirred for 30 min.

[0010] Furthermore, the mass ratio of the Pd atomic mass in the PdCl2 added in step (2) to the N-CeO2 is 1% to 12%, and the molar concentration of the NaBH4 aqueous solution is 1.0 to 2.5 mol / L.

[0011] The method for preparing the formic acid decomposition hydrogen production catalyst with light-responsive characteristics provided by the present invention can also adopt the following steps: (1) At room temperature, trisodium citrate dihydrate and CO(NH2)2 were dissolved in deionized water in succession and stirred to fully dissolve the solutes to obtain solution A; Ce(NO3)3•6H2O was then added to solution A and stirred continuously to obtain solution B. Solution B was then transferred to a high-pressure reactor and the high-pressure reactor was placed in a thermostat for heat preservation. After the heat preservation was completed, the solution was naturally cooled to room temperature to obtain solution C. PdCl2 was added to solution C and stirred thoroughly to obtain solution D. The newly prepared NaBH4 aqueous solution was then added dropwise to solution D while stirring vigorously. The reaction time was not less than 50 min. After the reaction was completed, the product was washed with anhydrous ethanol and deionized water respectively to remove impurities in the product; the washed solution was centrifuged to obtain a precipitate, and the precipitate was dried; (2) The powder obtained after drying in step (1) is calcined under an argon atmosphere to obtain a formic acid decomposition hydrogen production catalyst with photoresponsive characteristics, which is denoted as PdN-CeO2.

[0012] Furthermore, in the method, in step (1), Ce(NO3)3•6H2O is added to solution A and stirred for 2 hours to obtain solution B; the high-pressure reactor is placed in a constant temperature box at 180-200°C and kept warm for 24 hours; the concentration of the newly prepared NaBH4 aqueous solution is 1.0-2.5 mol / L; after the reaction is completed, the solution is washed with anhydrous ethanol and deionized water three times respectively; the precipitate is dried at 80°C for 5 hours; Further, in step (2) of this method, the powder is calcined in an argon atmosphere at 350 - 550 °C for 4 - 6 hours.

[0013] The object of the present invention also lies in providing a formic acid decomposition hydrogen production catalyst with light response characteristics obtained according to the above two preparation methods.

[0014] The principle of the preparation method of the formic acid decomposition hydrogen production catalyst with light response characteristics of the present invention: The wide-bandgap semiconductor catalyst CeO2 with corrosion resistance and simple preparation method is used. N element is used to dope and modify the semiconductor catalyst CeO2. By utilizing the function of N element as an electron acceptor, the outer electron orbit of Ce atoms in CeO2 is doped, reducing the bandgap width of CeO2, and then improving the response ability of CeO2 to long-wavelength light. Then, in-situ generation and deposition of Pd metal element are carried out on N-doped CeO2 (N-CeO2). Pd metal not only has the effect of efficiently catalyzing the decomposition of formic acid to produce hydrogen, but also regulates the energy band structure of CeO2, further enhancing the response ability of CeO2 to long-wavelength light. At the same time, the metal conductor property of Pd metal can effectively separate photo-generated electron-hole pairs, reduce the recombination rate of photo-generated electron-hole pairs, and thus improve the photocatalytic efficiency.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a catalytic formic acid decomposition high-efficiency hydrogen production catalyst and its preparation method that are simply synthesized, easy to promote industrially, and have a wide-spectrum effect. This catalyst has a broad spectral response range, can utilize visible light with a relatively long wavelength or even infrared light, has a 100% selectivity for catalytic formic acid hydrogen production, and still has good catalytic formic acid hydrogen production activity at room temperature (25 °C). The synthesis process of the catalyst is simple, facilitating batch synthesis, and suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a spectral response influence diagram of PdN-CeO2 obtained in Example 1 of the present invention, N-CeO2 obtained in step (1) of Example 1, CeO2 obtained in Comparative Example 1, and Pd-CeO2 obtained in Comparative Example 2; Figure 2 It is an SEM diagram of the catalyst PdN-CeO2 obtained in Example 1 of the present invention; Figure 3 It is the catalytic formic acid decomposition gas production performance of the catalyst PdN-CeO2 obtained in Example 1 and Example 2 of the present invention under light irradiation conditions and non-light irradiation conditions respectively; Figure 4 For Figure 3 It is the component analysis spectrum of the gas produced by the catalytic decomposition of formic acid by the catalyst PdN-CeO2 in Example 1 under light irradiation conditions in DETAILED DESCRIPTION OF THE INVENTION

[0017] To better understand the content of the present invention, the present invention will be further elaborated below in combination with specific embodiments and drawings. The following embodiments are implemented based on the technology of the present invention, and detailed implementation manners and operation steps are given, but the protection scope of the present invention is not limited to the following embodiments.

[0018] In specific implementation, the sequence of doping with N element and depositing Pd metal element can be reversed. For example, in Example 1, doping with N element is carried out first and then depositing Pd metal element, while in Example 2, depositing Pd metal element is carried out first and then doping with N element; the purity of APTS is 99%.

[0019] Example 1: (1) Dissolve 20 g of Ce(NO3)3•6H2O in deionized water to obtain a Ce(NO3)3 solution with a molar concentration of 1.0 mol / L. Then slowly drip 15 mL of a 1 mol / L NaOH aqueous solution into the above Ce(NO3)3 solution, and perform magnetic stirring during the dripping process to ensure uniform mixing. Subsequently, add 5 mL of a 0.5 mol / L CO(NH2)2 solution, and then stir magnetically for 20 min to make it evenly mixed. Transfer the obtained mixed solution to a high-pressure reaction kettle, and then place the high-pressure reaction kettle in an incubator at 180 °C for reaction, and the reaction time is 24 h; after the reaction is completed, cool it to room temperature, centrifuge the reaction solution, discard the supernatant, wash the precipitate 3 times with deionized water and anhydrous ethanol respectively, then dry it at 80 °C for 5 hours, transfer the dried powdery substance to a roasting furnace, and roast it at 500 °C for 5 hours to obtain an N-doped CeO2 sample, denoted as N-CeO2; (2) Weigh 8 g of the N-CeO2 sample obtained in step (1) and ultrasonically disperse it in 40 mL of deionized water to form an N-CeO2 suspension. Add 0.6 mL of APTS to this suspension, then stir for 30 min, and then add 0.14 g of PdCl2 to the above suspension as well. Stir well to obtain a dispersion liquid, and then slowly drip 10 mL of a newly prepared 2 mol / L NaBH4 solution into the above dispersion liquid drop by drop, while vigorously stirring during the addition, and the reaction time is 50 min. After the reaction is completed, centrifuge the obtained product, discard the supernatant, wash the precipitate with deionized water, and finally dry and grind it to obtain a formic acid decomposition hydrogen production catalyst with light response characteristics, denoted as PdN-CeO2.

[0020] Example 2: (1) At room temperature, 1.5 g of trisodium citrate dihydrate and 1.0 g of CO(NH2)2 were successively dissolved in 40 mL of deionized water and magnetically stirred to fully dissolve the solutes, obtaining solution A; then 20 g of Ce(NO3)3•6H2O was added to solution A, and stirring was continued at room temperature for 2 h to fully dissolve cerium nitrate and mix it with other components in solution A, obtaining solution B. Subsequently, solution B was transferred to a high-pressure reaction kettle, and the high-pressure reaction kettle was placed in an incubator at 180 °C for heat preservation for 24 hours. During the heat preservation process, chemical reactions occurred among the substances in the solution. After the heat preservation was completed, it was naturally cooled to room temperature to obtain solution C. 0.39 g of PdCl2 was added to solution C, and after sufficient stirring, solution D was obtained. Then, 10 mL of freshly prepared aqueous NaBH4 solution with a concentration of 2 mol / L was added dropwise to solution D while vigorously stirring. The reaction time was 50 min. After the reaction was completed, the resulting solution was centrifuged to obtain a precipitate. The precipitate was washed 3 times each with absolute ethanol and deionized water to remove impurities, and then the precipitate was dried at 80 °C for 5 hours to remove the moisture therein; (2) The powder obtained after drying in step (1) was calcined in an argon atmosphere at 500 °C for 5 hours to obtain a hydrogen production catalyst for formic acid decomposition with light response characteristics, denoted as PdN-CeO2.

[0021] Example 3: (1) 30 g of Ce(NO3)3•6H2O was dissolved in deionized water to obtain a Ce(NO3)3 solution with a molar concentration of 2.0 mol / L. Then, 15 mL of an aqueous NaOH solution with a concentration of 1 mol / L was slowly added dropwise to the above Ce(NO3)3 solution. Magnetic stirring was carried out during the dropping process to ensure uniform mixing. Subsequently, 5 mL of an aqueous CO(NH2)2 solution with a concentration of 0.5 mol / L was added, and then magnetic stirring was carried out for 20 min to mix it evenly. The resulting mixed solution was transferred to a high-pressure reaction kettle, and the high-pressure reaction kettle was placed in an incubator at 200 °C for reaction for 24 h; after the reaction was completed, it was cooled to room temperature. The reaction solution was centrifuged to discard the supernatant. The precipitate was washed 3 times each with deionized water and absolute ethanol, and then dried at 80 °C for 5 hours. The powdered substance obtained after drying was transferred to a roasting furnace and calcined at 450 °C for 5 hours to obtain an N-doped CeO2 sample, denoted as N-CeO2; (2) Weigh 16 g of the N-CeO2 sample obtained in step (1) and ultrasonically disperse it in 50 mL of deionized water to form an N-CeO2 suspension. Add 0.6 mL of APTS to this suspension, then stir for 30 min. Next, add 0.28 g of PdCl2 to the above suspension and stir well to obtain a dispersion. Then, gradually add 10 mL of freshly prepared NaBH4 solution with a concentration of 2.5 mol / L dropwise to the above dispersion while vigorously stirring. The reaction time is 50 min. After the reaction, centrifuge the resulting product, discard the supernatant, wash the precipitate with deionized water, and finally dry and grind it to obtain a hydrogen production catalyst for formic acid decomposition with light-responsive properties, denoted as PdN-CeO2.

[0022] Example 4: (1) At room temperature, dissolve 3 g of trisodium citrate dihydrate and 1.5 g of CO(NH2)2 successively in 40 mL of deionized water and stir magnetically to fully dissolve the solutes to obtain solution A; then add 40 g of Ce(NO3)3·6H2O to solution A and continue to stir at room temperature for 2 h to fully dissolve cerium nitrate and mix it with other components in solution A to obtain solution B. Then transfer solution B to a high-pressure reaction kettle and place the high-pressure reaction kettle in an incubator at 200 °C for 24 h. During the insulation process, chemical reactions will occur among the substances in the solution. After the insulation is completed, naturally cool to room temperature to obtain solution C. Add 0.78 g of PdCl2 to solution C and stir well to obtain solution D. Then, gradually add 10 mL of freshly prepared aqueous NaBH4 solution with a concentration of 2.5 mol / L dropwise to solution D while vigorously stirring. The reaction time is 50 min. After the reaction, centrifuge the resulting solution to obtain a precipitate. Wash the precipitate 3 times each with absolute ethanol and deionized water to remove impurities, and then dry the precipitate at 80 °C for 5 h to remove the moisture therein.

[0023] (2) Calcinate the powder obtained after drying in step (1) in an argon atmosphere at 450 °C for 5 h to obtain a hydrogen production catalyst for formic acid decomposition with light-responsive properties, denoted as PdN-CeO2.

[0024] Comparative Example 1: Dissolve 20 g of Ce(NO3)3•6H2O in deionized water to obtain a Ce(NO3)3 solution with a molar concentration of 2.0 mol / L. Then, slowly add 15 mL of a 1 mol / L NaOH aqueous solution dropwise to the above Ce(NO3)3 solution, and perform magnetic stirring during the dropping process to ensure uniform mixing. Transfer the obtained mixed solution to a high-pressure reactor, and then place the high-pressure reactor in an incubator at 180 °C for reaction for 24 h; after the reaction, cool it to room temperature, centrifuge the reaction solution, discard the supernatant, wash the precipitate 3 times with deionized water and anhydrous ethanol respectively, and then dry it at 80 °C for 5 hours. Transfer the dried powdery substance to a roasting furnace and roast it at 500 °C for 5 hours to obtain a pure CeO2 sample, denoted as CeO2; Comparative Example 2: Weigh 8 g of the CeO2 sample obtained in Comparative Example 1 and ultrasonically disperse it in 40 mL of deionized water to form a CeO2 suspension. Add 0.6 mL of APTS to this suspension, then stir for 30 min, and then add 0.14 g of PdCl2 to the above suspension as well. Stir well to obtain a dispersion, and then slowly add 10 mL of a newly prepared 2 mol / L NaBH4 solution dropwise to the above dispersion, and stir vigorously while adding. The reaction time is 50 min. After the reaction, centrifuge the obtained product, discard the supernatant, wash the precipitate with deionized water, and finally dry and grind it to obtain a semiconductor catalyst deposited with Pd metal, denoted as Pd-CeO2.

[0025] Figure 1 It is a graph showing the influence of spectral response of PdN-CeO2 obtained in Example 1 of the present invention, N-CeO2 obtained in step (1) of Example 1, CeO2 obtained in Comparative Example 1, and Pd-CeO2 obtained in Comparative Example 2; the figure shows that the doping of non-metallic element N (N-CeO2) improves the response absorption ability of CeO2 to long-wavelength light from 300 nm to 800 nm, while the doping of metallic element Pd (Pd-CeO2) improves the response absorption ability of CeO2 to short-wavelength light with a wavelength of 100 nm to 250 nm. The light response absorption ability of the catalyst PdN-CeO2 modified by co-doping of N and Pd is significantly improved in the full wavelength range.

[0026] Figure 2 It is the SEM image of the catalyst PdN-CeO2 obtained in Example 1. From Figure 2 it can be seen that the catalyst prepared by the hydrothermal method in Example 1 has a honeycomb pore structure, and the pore size is 20 - 50 nm. The honeycomb pore structure is beneficial to increasing the specific surface area of the catalyst and improving the adsorption ability of reactants on the catalyst surface, and thus is beneficial to the progress of the catalytic reaction.

[0027] The catalysts PdN-CeO2 prepared in Examples 1 and 2 were respectively used for hydrogen production by formic acid decomposition. The reactant formic acid was of analytical purity. The mass ratio of the catalyst to formic acid added was 1:10 in both cases. The reaction temperature was controlled at 50 °C by a thermocouple and a heating jacket. The amount of gas produced was collected and measured by the water displacement method. Before the experiment, the experimental apparatus and pipelines were purged with nitrogen of 99.99% purity to ensure that all the air in the apparatus and pipelines was exhausted. The purity of the product hydrogen was determined by a gas chromatograph, and a 50 W xenon lamp was used to simulate sunlight.

[0028] Figure 3 Shown are the performances of the catalysts PdN-CeO2 obtained in Example 1 and Example 2 for catalytic formic acid decomposition to produce gas under light and non-light conditions. Figure 3 It can be seen that under non-light conditions, the catalysts PdN-CeO2 corresponding to Example 1 and Example 2 can both efficiently catalyze the decomposition of formic acid to generate a mixed gas. The rate of the catalyst PdN-CeO2 corresponding to Example 1 for catalyzing the decomposition of formic acid to generate a mixed gas is slightly higher than that of the catalyst PdN-CeO2 corresponding to Example 2. At the same time, the catalysts in both examples can respond to visible light. Under light conditions, both the efficiency and rate of formic acid decomposition to produce a mixed gas are increased. For the catalyst obtained in Example 1, with the introduction of light conditions, the rate of formic acid decomposition to produce a mixed gas is increased from 0.29 mL / min to 0.38 mL / min.

[0029] Figure 4 Shown is Figure 3 the component analysis spectrum of the gas produced by the catalyst PdN-CeO2 in Example 1 for catalytic formic acid decomposition under light conditions. The gas components generated by the catalyst catalyzing the decomposition of formic acid were analyzed by a gas chromatograph. It was detected that the gas mainly contained H2 and CO2 and did not contain CO components. This indicates that in the catalytic formic acid decomposition reaction of the catalyst PdN-CeO2 in this example, the main reaction occurring was the dehydrogenation of formic acid, and the hydrogen production selectivity reached 100%. The N2 component shown by the N2 signal peak in the figure was due to the residual high-purity nitrogen used to purge the experimental apparatus and pipelines.

[0030] The above are only examples of the present invention and do not impose any form of limitation on the present invention. The present invention can also have other forms of embodiments based on the above structures and functions, which will not be listed one by one. Therefore, any person skilled in the art, without departing from the scope of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A preparation method of a formic acid decomposition hydrogen production catalyst with light response characteristics, characterized in that, The specific steps include: (1) Ce(NO3)3•6H2O was dissolved in deionized water to obtain a Ce(NO3)3 solution, and then a NaOH aqueous solution was slowly added dropwise to the Ce(NO3)3 solution, and magnetic stirring was performed during the addition process. Then, a CO(NH2)2 aqueous solution was added, and then magnetic stirring was performed to mix uniformly. The obtained mixed solution was transferred to a high-pressure reactor, and then the high-pressure reactor was placed in a constant temperature box at 180℃~200℃ for reaction, and the reaction time was not less than 24h; after the reaction was completed, it was cooled to room temperature, the reaction solution was centrifuged, the supernatant was discarded, and the precipitate was washed, dried, and calcined to obtain N-doped CeO2, which was recorded as N-CeO2; (2) N-CeO2 was ultrasonically dispersed in deionized water to form an N-CeO2 suspension. APTS was added to the suspension and stirred. PdCl2 was also added to the suspension and stirred thoroughly to obtain a dispersion. The newly prepared NaBH4 aqueous solution was then added dropwise to the dispersion while stirring vigorously. The reaction time was not less than 30 min. After the reaction was completed, the obtained product was centrifuged, washed, dried, and ground to obtain a formic acid decomposition hydrogen production catalyst with light-responsive characteristics, which was recorded as PdN-CeO2.

2. The preparation method of the formic acid decomposition hydrogen production catalyst with light response characteristics according to claim 1, characterized in that, In step (1), the molar concentration of the Ce(NO3)3 solution is 1~5 mol / L; the molar concentration of the NaOH aqueous solution is 1 mol / L; and the concentration of the CO(NH2)2 aqueous solution is 0.5~1.5 mol / L.

3. The preparation method of the formic acid decomposition hydrogen production catalyst with light response characteristics according to claim 1, characterized in that, In step (1), the volume ratio of CO(NH2)2 aqueous solution to Ce(NO3)3 solution is (1~3):

20.

4. The preparation method of the formic acid decomposition hydrogen production catalyst with light response characteristics according to claim 1, characterized in that, In step (1), the calcination step is carried out at 350°C to 550°C for 4-6 hours; and washing step is washing the precipitate with deionized water and anhydrous ethanol three times respectively.

5. The preparation method of the formic acid decomposition hydrogen production catalyst with light response characteristics according to claim 1, characterized in that, In step (2), N-CeO2 is ultrasonically dispersed in deionized water to form an N-CeO2 suspension with a concentration of 0.1-0.4 g / mL; 0.5-3.5 mL of APTS is added to the N-CeO2 suspension and stirred for 30 minutes.

6. The preparation method of the formic acid decomposition hydrogen production catalyst with light response characteristics according to claim 1, characterized in that, The mass ratio of the Pd atomic mass in the PdCl2 added in step (2) to the N-CeO2 is 1% to 12%, and the molar concentration of the NaBH4 aqueous solution is 1.0 to 2.5 mol / L.

7. The preparation method of the formic acid decomposition hydrogen production catalyst with light response characteristics according to claim 1, characterized in that, The preparation steps are replaced as follows: (1) At room temperature, sodium citrate dihydrate and CO(NH2)2 were successively dissolved in deionized water and stirred to fully dissolve the solutes to obtain solution A; then Ce(NO3)3•6H2O was added to solution A and stirring was continued to obtain solution B. After that, solution B was transferred to a high-pressure reaction kettle, and the high-pressure reaction kettle was placed in an incubator for heat preservation. After the heat preservation was completed, it was naturally cooled to room temperature to obtain solution C. PdCl2 was added to solution C and stirred thoroughly to obtain solution D. Then, the newly prepared aqueous solution of NaBH4 was added dropwise to solution D while stirring vigorously. The reaction time was not less than 50 min. After the reaction was completed, it was washed with absolute ethanol and deionized water respectively to remove impurities in the product; the washed solution was centrifuged to obtain a precipitate, and the precipitate was dried. (2) The powder obtained after drying in step (1) was calcined in an argon atmosphere to obtain a hydrogen production catalyst for formic acid decomposition with light response characteristics, denoted as PdN-CeO2.

8. The preparation method of the formic acid decomposition hydrogen production catalyst with light response characteristics according to claim 7, characterized in that, In step (1), Ce(NO3)3•6H2O was added to solution A and stirring was continued for 2 h to obtain solution B; the high-pressure reaction kettle was placed in an incubator at 180 - 200 °C for heat preservation for 24 hours; the concentration of the newly prepared aqueous solution of NaBH4 was 1.0 - 2.5 mol / L; after the reaction was completed, it was washed 3 times each with absolute ethanol and deionized water; the precipitate was dried at 80 °C for 5 hours.

9. The preparation method of the formic acid decomposition hydrogen production catalyst with light response characteristics according to claim 7, characterized in that, In step (2), the powder was calcined in an argon atmosphere at 350 - 550 °C for 4 - 6 hours.

10. A hydrogen production catalyst for formic acid decomposition with light response characteristics prepared by the preparation method according to any one of claims 1 - 9.

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