[0051] Such as figure 1 As shown, the present invention provides a method for preparing an ordered nanostructured membrane electrode applied to a fuel cell. The preparation method of the ordered nanostructured membrane electrode at least includes the following steps:
[0052] S1, providing a substrate and a porous template, the substrate comprising carbon paper and an electrode microporous layer coated on the carbon paper;
[0053] S2, preparing an adhesive, and bonding the porous template and the electrode microporous layer through the adhesive;
[0054] S3, preparing a mixed electroplating solution, and preparing a nano-array on the surface of the electrode microporous layer by electrodeposition;
[0055] S4, post-treatment of the deposited product, including removing the porous template and the binder, thereby preparing an ordered nano-array catalytic electrode;
[0056] S5, using the ordered nano-array catalytic electrode as a cathode and/or an anode, placing a proton exchange membrane between the cathode and the anode and forming a membrane electrode by hot pressing.
[0057] The method for preparing the ordered nanostructured membrane electrode of the present invention will be described in detail below.
[0058] First, step S1 is performed: providing a substrate and a porous template. The substrate includes carbon paper and an electrode microporous layer coated on the carbon paper.
[0059] The specific process of coating the microporous layer of the electrode is: mixing carbon powder, polytetrafluoroethylene (Polytetrafluoro Ethylene, PTFE) solution, and isopropanol (Iso-Propyl Alcohol, IPA) aqueous solution, and then sonicating it for 30 to 150 minutes. Coating on carbon paper with a mass fraction of 0~40% PTFE, the loading capacity is 0~2.0mg·cm -2 The carbon powder mixed with the PTFE solution and the IPA aqueous solution is sintered at a temperature of 100 to 500° C. for 10 to 60 minutes to obtain the electrode microporous layer.
[0060] The carbon powder may be a carbon nanotube material, a carbon fiber material or a carbon microsphere material. Of course, the carbon powder may also be other suitable carbon materials, which is not limited here.
[0061] The porous template is an anodic aluminum oxide template, a titanium dioxide nanotube template, or a polycarbonate porous template. Of course, the porous template may also be other suitable porous materials, which is not limited here.
[0062] Then, step S2 is performed: an adhesive is prepared, and the porous template is bonded to the electrode microporous layer through the adhesive.
[0063] The specific method of configuring the binder is: mixing Polyvinylidene Fluoride (PVDF) and N-Methyl Pyrrolidone (NMP) and magnetically stirring at 20~80℃ for 1~10h. A PVDF solution with a mass fraction of 2% to 15% is used as a binder.
[0064] The specific method for bonding the porous template and the substrate is: 2.0~15.0mg·cm -2 The PVDF solution is coated on the electrode microporous layer, and then a porous template with a double through hole diameter of 50-400 nm is bonded on the electrode microporous layer and left to stand for 0-30 minutes.
[0065] Then, step S3 is performed: preparing a mixed electroplating solution, and preparing a nano-array on the surface of the electrode microporous layer by electrodeposition.
[0066] The preparation method of the mixed electroplating solution is as follows: the platinum precursor or the platinum precursor and the noble metal compound are mixed with the acid solution and the lead salt to prepare the mixed electroplating solution, and then stand for 0-24 hours. Wherein, the platinum precursor can be one or a mixture of sodium chloroplatinate and chloroplatinic acid, and the noble metal compound can be palladium chloride, nickel chloride, chromium chloride, nickel nitrate, chromium nitrate Or ruthenium trichloride, the acid solution can be perchloric acid or dilute sulfuric acid, and the lead salt can be lead acetate or lead nitrate. In this embodiment, the concentration of the platinum precursor in the mixed electroplating solution is 1-10 mM, the concentration of the noble metal compound is 1-10 mM, the acid concentration is 0.01-0.2 M, and the lead salt concentration is 0.02 ~0.4mM.
[0067] The method of electrodeposition in this step is as follows: first, the bonded substrate and the porous template, and the electroplating solution are loaded into the deposition device; then, the carbon paper is used as the working electrode, and the microporous layer side Direct contact with the electroplating solution, platinum wire as the counter electrode, saturated calomel electrode as the reference electrode, and cyclic voltammetry for electrodeposition; the electrodeposition voltage is set to -1.0~0V, and the electrodeposition time is set to 1000~15000s Electrodeposition is carried out under the protection of nitrogen; after the electrodeposition is completed, the deposition device is disassembled, and the electrode microporous layer deposited with platinum or platinum alloy nano-array is allowed to stand for 4-24 hours. The morphology and size of the platinum or platinum alloy nanoarray can be adjusted by the deposition time and the concentration of the mixed electroplating solution, and the platinum or platinum alloy nanoarray finally obtained can be nanowires or nanotubes.
[0068] It should be noted that the nanoarray grown by electrodeposition is grown on the surface of the electrode microporous layer, and the nanoarray passes through the double through holes of the porous template.
[0069] Then, step S4: post-processing of the deposited product is performed; including removing the porous template and the binder, so as to prepare an ordered nano-array catalytic electrode.
[0070] The specific process is: the nanoarray prepared by electrodeposition is dissolved to remove the porous template. For example, if the porous template is an alkaline or amphoteric template such as anodized aluminum oxide template or titanium dioxide nanotube template, use the concentration setting 1.0-3.0M lye to dissolve the porous template; if the porous template is a polycarbonate porous template, use carbon tetrachloride, chloroform or tetrahydrofuran solvent to dissolve the porous template, and then use water, Alternate washing with ethanol for several times, and vacuum drying at a temperature of 30-100° C., to obtain the ordered nano-array catalytic electrode. The ordered nano-array catalytic electrode is used as a cathode and/or anode in a membrane electrode of a direct methanol fuel cell.
[0071] Finally, step S5 is performed: using the ordered nano-array catalytic electrode as the cathode and/or anode, placing a proton exchange membrane between the cathode and the anode and forming a membrane electrode by hot pressing.
[0072] A layer of Nafion resin is attached to the surface of the ordered nano-array electrode by spraying or scraping, and after drying treatment, under the conditions of 130℃ and 3-6MPa, hot-pressing to form a "triad of cathode, anode and proton exchange membrane" One" membrane electrode assembly.
[0073] The present invention also provides an ordered nanostructured membrane electrode, which is prepared by the above preparation method. The structure of the membrane electrode includes: a cathode, an anode, and protons formed between the cathode and the anode by hot pressing. Exchange membrane. Wherein, the cathode and the anode may both be the ordered nano-array catalytic electrode prepared by the present invention, or only the anode or the cathode may be the ordered nano-array catalytic electrode prepared by the present invention.
[0074] The ordered nano-array catalytic electrode at least includes: a substrate including carbon paper and an electrode microporous layer coated on the carbon paper; and a nano-array deposited on the surface of the electrode microporous layer.