A method for preparing an ultra-low chlorine content platinum-carbon catalyst
By using platinum nitrate as a platinum precursor, combined with high-shear emulsification and inert gas protection, a platinum-carbon catalyst with ultra-low chlorine content was prepared, solving the problem of high chlorine content in the catalyst and improving catalyst performance and service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHAOXING CAMBRIAN ENERGY CO LTD
- Filing Date
- 2026-02-02
- Publication Date
- 2026-06-09
AI Technical Summary
The high chlorine content in existing Pt/C catalysts leads to decreased catalyst performance and shortened service life. In particular, chloride ions participate in oxidation reactions in electrochemical systems, exacerbating corrosion.
Platinum nitrate was used as a platinum precursor, and a platinum-carbon catalyst with ultra-low chlorine content was prepared by controlling the reaction temperature and time through high-shear emulsification and inert gas protection.
It significantly reduces the chlorine content in the catalyst, improves performance and extends service life, and avoids the corrosive effects of chloride ions on the catalyst.
Smart Images
Figure CN122164513A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hydrogen energy technology, specifically to a method for preparing an ultra-low chlorine content platinum-carbon catalyst. Background Technology
[0002] Currently, chloroplatinic acid is conventionally used as a platinum precursor in the preparation of Pt / C catalysts. This has resulted in chlorine content in commercially available Pt / C catalysts ranging from 100 ppm to 500 ppm, negatively impacting catalyst performance. Specifically, chloride ions strongly adsorb onto platinum (Pt) active sites, forming stable platinum-chlorine compounds (such as PtCl4²⁻), which directly occupy the catalytic reaction centers, leading to decreased activity. Simultaneously, chloride ions corrode the carbon support, disrupting its anchoring effect on platinum particles and causing platinum nanoparticle aggregation. Furthermore, in electrochemical systems (such as fuel cells), chloride ions may participate in oxidation reactions to generate hypochlorous acid (HClO), exacerbating catalyst and electrode corrosion, thus affecting catalyst performance and shortening its lifespan. Summary of the Invention
[0003] To address the aforementioned problems, this invention provides a method for preparing an ultra-low chlorine content platinum-carbon catalyst using platinum nitrate as a platinum precursor, which effectively reduces the chlorine content in the catalyst and overcomes the process difficulties caused by platinum precursor substitution.
[0004] To address the shortcomings of existing technologies, the present invention provides the following technical solution: A method for preparing an ultra-low chlorine content platinum-carbon catalyst includes the following steps: Step 1: Add the carbon support to the polyol solvent and mix and stir, then perform high-shear homogenization emulsification for 20-180 min; Step 2: Add platinum nitrate; Step 3: Perform high-shear emulsification and dispersion for 30-180 minutes, during which inert gas is passed through for protection; Step 4: The reaction is carried out at a constant temperature of 110℃-160℃ for 0.5h-10h; Step 5: Clean the filter; Step 6: Drying and grinding; Step 7: Inspection and warehousing.
[0005] Preferably, the carbon carrier is carbon black.
[0006] Preferably, the polyol solvent is ethylene glycol.
[0007] Preferably, in step 4, the reaction temperature is 130℃-160℃.
[0008] More preferably, in step 4, the reaction temperature is 140℃-150℃.
[0009] Preferably, in step 4, the reaction time is 4-8 hours.
[0010] More preferably, in step 4, the reaction time is 5.5h-6.5h.
[0011] The present invention also provides a platinum-carbon catalyst prepared by the method described above.
[0012] Furthermore, in the platinum-carbon catalyst, the mass content of platinum is 20-70%.
[0013] The present invention also provides a catalyst coating film prepared by the above-mentioned platinum-carbon catalyst.
[0014] Compared with existing technologies, the advantages of this invention are as follows: In the preparation process of this invention, the conventionally used chloroplatinic acid precursor is replaced with platinum nitrate. The chlorine content in the resulting catalyst is detected to be below 0.1 mg / L, thereby improving catalyst performance and helping to extend the catalyst's lifespan. Furthermore, this invention overcomes the technical difficulties caused by the replacement of the platinum precursor through precise control of process parameters. Attached Figure Description
[0015] Figure 1 This is a transmission electron microscope (TEM) image of the platinum-carbon catalyst prepared in Experimental Example 1 of this invention.
[0016] Figure 2 This is a histogram of the particle size distribution of the platinum-carbon catalyst prepared in Experimental Example 1 of this invention.
[0017] Figure 3 This is an energy dispersive spectroscopy (EDS) analysis report of the platinum-carbon catalyst prepared in Experimental Example 1 of this invention.
[0018] Figure 4 This is a polarization curve of the platinum-carbon catalyst prepared in Experimental Example 1 of this invention.
[0019] Figure 5 This is a transmission electron microscope (TEM) image of the platinum-carbon catalyst prepared in Experimental Example 2 of this invention.
[0020] Figure 6 This is a histogram of the particle size distribution of the platinum-carbon catalyst prepared in Experimental Example 2 of this invention.
[0021] Figure 7 This is the energy dispersive spectroscopy (EDS) analysis report of the platinum-carbon catalyst prepared in Experimental Example 2 of this invention.
[0022] Figure 8 This is a polarization curve of the platinum-carbon catalyst prepared in Experimental Example 2 of this invention.
[0023] Figure 9 This is a transmission electron microscope (TEM) image of the platinum-carbon catalyst prepared in Experimental Example 3 of this invention.
[0024] Figure 10 This is a histogram of the particle size distribution of the platinum-carbon catalyst prepared in Experimental Example 3 of this invention.
[0025] Figure 11 This is a color transmission electron microscope image of the platinum-carbon catalyst prepared in Experimental Example 3 of the present invention.
[0026] Figure 12 This is an energy dispersive spectroscopy (EDS) analysis report of the platinum-carbon catalyst prepared in Experimental Example 3 of this invention.
[0027] Figure 13 This is a polarization curve of the platinum-carbon catalyst prepared in Experimental Example 3 of this invention.
[0028] Figure 14 This is a transmission electron microscope (TEM) image of the platinum-carbon catalyst prepared in Experimental Example 4 of this invention.
[0029] Figure 15 This is a histogram of the particle size distribution of the platinum-carbon catalyst prepared in Experimental Example 4 of this invention.
[0030] Figure 16 This is a statistical analysis report on the particle size distribution of the platinum-carbon catalyst prepared in Experimental Example 4 of this invention (NanoMeasurer).
[0031] Figure 17 This is a polarization curve of the platinum-carbon catalyst prepared in Experimental Example 4 of this invention.
[0032] Figure 18 This is a transmission electron microscope (TEM) image of the platinum-carbon catalyst prepared in Experimental Example 5 of this invention.
[0033] Figure 19 This is a histogram of the particle size distribution of the platinum-carbon catalyst prepared in Experimental Example 5 of this invention.
[0034] Figure 20 This is a statistical analysis report on the particle size distribution of the platinum-carbon catalyst prepared in Experimental Example 5 of this invention (NanoMeasurer).
[0035] Figure 21 This is a polarization curve of the platinum-carbon catalyst prepared in Experimental Example 5 of this invention.
[0036] Figure 22 This is a comparison of the X-ray diffraction (XRD) patterns of sample 1# 201 and sample 2# 202 in this invention.
[0037] Figure 23 This is a comparison chart of the pore size distribution curves of sample 1# 201 and sample 2# 202 in this invention.
[0038] Figure 24 This is a comparison of nitrogen adsorption-desorption isotherms (BET) of samples 1# 201 and 2# 202 in this invention. Detailed Implementation
[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments. Example
[0040] A method for preparing an ultra-low chlorine content platinum-carbon catalyst includes the following steps: 1. First, add 0.25-2.40 parts by weight of carbon black to ethylene glycol and mix and stir for 20-180 minutes, then perform high-shear homogenization emulsification for 20-180 minutes; 2. Add 0.55-4.66 parts by weight of platinum nitrate as required; 3. Perform high-shear emulsification dispersion for 30-180 minutes (with inert gas protection during the process); 4. The reaction was carried out at a constant temperature of 110℃-160℃ for N hours; 5. Clean the filter; 6. Drying and grinding; 7. Inspection and warehousing. Experimental Example 1 1. First, add 1.2g of carbon black to 690ml of ethylene glycol and mix for 60min, then perform high-shear homogenization emulsification for 60min; 2. Add 3.1g of platinum nitrate as required; 3. Perform high-shear emulsification and dispersion for 90 minutes (with inert gas protection during the process); 4. The reaction was carried out at a constant temperature of 115℃ for 15 minutes; 5. Clean the filter; the filtrate will turn yellowish during the cleaning process. 6. Drying and grinding; 7. Performance testing, theoretical platinum content 60%.
[0041] Test results as follows Figure 1-4 As shown in the figure, analysis revealed that the obtained catalyst had low platinum content, small particle size, minimal agglomeration, and uniform distribution; the ECA was 15.3 μm. 2 / g, single-cell polarization data 0.206V@1A / cm 2 .
[0042] Correspondingly, when chloroplatinic acid is used in the same process as in Experimental Example 1 to prepare a platinum-carbon catalyst, the resulting platinum-carbon catalyst can already reach the theoretical platinum content. In comparison, simply replacing chloroplatinic acid with platinum nitrate cannot achieve the same product requirements, so the preparation process needs to be further improved. Experiment Example 2 1. First, add 1.2g of carbon black to 690ml of ethylene glycol and mix for 60min, then perform high-shear homogenization emulsification for 60min; 2. Add 3.1g of platinum nitrate as required; 3. Perform high-shear emulsification dispersion for 90 minutes (with inert gas protection during the process); 4. The reaction was carried out at a constant temperature of 115℃ for 2 hours; 5. Clean the filter; the filtrate will turn yellowish during the cleaning process. 6. Drying and grinding; 7. Performance testing, theoretical platinum content 60%.
[0043] Test results as follows Figure 5-8 As shown in the figure, the analysis revealed that compared to the catalyst obtained in Experimental Example 1, the platinum content was slightly increased, the particle size was smaller, there was less agglomeration, and the distribution was more uniform; the ECA was 66.27 μm. 2 / g, single-cell polarization data 0.571V@1A / cm 2 . Experimental Example 3 1. First, add 1.2g of carbon black to 690ml of ethylene glycol and mix for 60min, then perform high-shear homogenization emulsification for 60min; 2. Add 3.1g of platinum nitrate as required; 3. Perform high-shear emulsification dispersion for 90 minutes (with inert gas protection during the process); 4. The reaction was carried out at a constant temperature of 125℃ for 6 hours; 5. Clean the filter; 6. Drying and grinding; 7. Performance testing.
[0044] Test results as follows Figure 9-13 As shown, the filtrate was transparent during washing and filtration, with a theoretical platinum content of 60% and an actual measured platinum content of 52.11%; the ECA was 48.23 mg / L. 2 / g, mass activity 11.49 A / g, single-cell polarization data 0.647 V @ 1 A / cm 2 . Example
[0045] 1. First, add 1.2g of carbon black to 690ml of ethylene glycol and mix for 90min, then perform high-shear homogenization emulsification for 90min; 2. Add 3.1g of platinum nitrate as required; 3. Perform high-shear emulsification dispersion for 180 min (with inert gas protection during the process); 4. The reaction was carried out at a constant temperature of 135℃ for 6 hours (to obtain sample 1# 201). 5. Clean the filter; 6. Drying and grinding; 7. Performance testing.
[0046] Test results as follows Figure 14-17 As shown, the filtrate was transparent during washing and filtration, with a theoretical platinum content of 60% and an actual measured platinum content of 57.28%; the ECA was 60.36m. 2 / g, single-cell polarization data 0.701V@1A / cm 2 0.59V@2A / cm 2 . Experimental Example 5 1. First, add 1.2g of carbon black to 690ml of ethylene glycol and mix for 90min, then perform high-shear homogenization emulsification for 90min; 2. Add 3.1g of platinum nitrate as required; 3. Perform high-shear emulsification dispersion for 180 min (with inert gas protection during the process); 4. The reaction was carried out at a constant temperature of 145℃ for 6 hours (to obtain sample 2# 202); 5. Clean the filter; 6. Drying and grinding; 7. Performance testing.
[0047] Test results as follows Figure 18-21 As shown, the filtrate was transparent during washing and filtration, with a theoretical platinum content of 60% and an actual measured platinum content of 60.29%; the ECA was 68.75m. 2 / g, single-cell polarization data 0.726V@1A / cm 2 0.6329v@2A / cm 2 . Comparison of Sample 1# 201 and Sample 2# 202: X-ray diffraction (XRD) patterns, for example Figure 22 As shown in the figure, the diffraction peak positions of the two samples are basically the same, indicating that their crystal structures are similar. However, the diffraction peak intensity of sample 2#202 is higher, indicating that sample 2#202 has better crystallinity.
[0048] Comparison of pore size distribution curves, for example Figure 23 As shown, the pore size is mainly concentrated below 5nm, and the proportion of low pore size is even higher in sample 2# 202.
[0049] Nitrogen adsorption-desorption isotherm (BET) comparison, for example Figure 24 As shown, the two curves follow the same trend, indicating good data repeatability, and the adsorption capacity of sample 2#202 is slightly higher.
[0050] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A method for preparing an ultra-low chlorine content platinum-carbon catalyst, characterized in that, Includes the following steps: Step 1: Add the carbon support to the polyol solvent and mix and stir, then perform high-shear homogenization emulsification for 20-180 min; Step 2: Add platinum nitrate; Step 3: Perform high-shear emulsification and dispersion for 30-180 minutes, during which inert gas is passed through for protection; Step 4: The reaction is carried out at a constant temperature of 110℃-160℃ for 0.5h-10h; Step 5: Clean the filter; Step 6: Drying and grinding; Step 7: Inspection and warehousing.
2. The method for preparing an ultra-low chlorine content platinum-carbon catalyst according to claim 1, characterized in that, The carbon carrier is carbon black.
3. The method for preparing an ultra-low chlorine content platinum-carbon catalyst according to claim 1, characterized in that, The polyol solvent is ethylene glycol.
4. The method for preparing an ultra-low chlorine content platinum-carbon catalyst according to claim 1, characterized in that, In step 4, the reaction temperature is 130℃-160℃.
5. The method for preparing an ultra-low chlorine content platinum-carbon catalyst according to claim 4, characterized in that, In step 4, the reaction temperature is 140℃-150℃.
6. The method for preparing an ultra-low chlorine content platinum-carbon catalyst according to claim 1, characterized in that, In step 4, the reaction time is 4-8 hours.
7. The method for preparing an ultra-low chlorine content platinum-carbon catalyst according to claim 6, characterized in that, In step 4, the reaction time is 5.5h-6.5h.
8. The platinum-carbon catalyst prepared by the method for preparing an ultra-low chlorine content platinum-carbon catalyst as described in claims 1-7.
9. The platinum-carbon catalyst according to claim 8, characterized in that, The platinum-carbon catalyst contains 20-70% platinum by mass.
10. A catalyst coating film prepared using the platinum-carbon catalyst as described in claim 8.