Preparation method of curved surface electrode catalyst layer

Abstract

The invention provides a preparation method of a curved surface electrode catalyst layer, which is characterized by comprising the following steps of: 1, preprocessing an electrode matrix; 2, carrying out electrochemical deposition on a catalyst: inserting the preprocessed electrode matrix into an electrochemical deposition pool, loading an electroplating bath containing catalyst cations in the electrochemical deposition pool, forming a three-electrode system with a reference electrode and a counter electrode with the electrode matrix as a working electrode, controlling the potential of the working electrode to be -0.7-0.5V relative to a standard hydrogen electrode for carrying out electrochemical deposition until the loading capacity of the catalyst on the electrode matrix reaches a preset loading capacity, then taking the electrode matrix out, rinsing with deionized water for drying in air for later use; 3, dipping in a perfluorinated sulfonic acid resin solution; 4, repeating the step 2 and the step 3 until the loading capacity of the catalyst on the electrode matrix reaches the set loading capacity of the catalyst, entering the step 5; and 5, activating an electrode.

Description

technical field [0001] The invention relates to a method for preparing an electrode catalyst layer, in particular to a method for preparing a curved surface electrode catalyst layer. Background technique [0002] Electrode substrates commonly used in various common electrochemical reactors including fuel cells, electrolytic cells, electrochemical cells, etc. mainly include carbon paper, carbon cloth, carbon felt, graphite plate and other electrochemically stable and corrosion-resistant carbon materials. The prices of carbon paper, carbon cloth, carbon felt, and graphite plate are all high, resulting in high cost of electrochemical reactors. Carbon paper, carbon cloth, carbon felt, graphite plate, etc. are generally used as planar electrodes. However, the study of W.R. Merida, G. McLean, N. Djilali, Journal of Power Sources, 102 (2001) 178-185. Compared with planar electrodes, electrodes can significantly improve the performance and volume power density of electrochemica...

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Problems solved by technology

For example, in the patent US2004072047-A1, the electrochemical deposition method is used to electrochemically deposit the catalyst, which will cause dendritic growth of the catalyst crystal, increase the particle size of the catalyst crystal, and reduce the electrochemical active surface area and catalytic activity of the catalyst; directly The adhesion method is to mix catalyst nanoparticles such as Pd black or Pd / C with deionized water and perfluorosulfonic acid resin Nafion solution in a certain proportion to form a catalyst slurry Catalyst ink, perform ultrasonic vibration to make it evenly dispersed, and then coat it On the surface of the electrode, the catalyst layer is formed after drying with a heat lamp; the nanoparticle catalyst used by the direct attachment method has a high activity, but this preparation method is only suitable for a flat electrode structure, and it is difficult to prepare a catalyst slurry on the surface of a curved electrode. Evenly distributed, and due to the uneven heating of the surface of the curved surface, the catalyst layer prepared by the direct adhesion method will appear cracking, delamination, and falling off caused by thermal stress, resulting in waste of catalyst, and even completely invalidating the catalyst

In addition, due to the agglomeration of catalyst nanoparticles in the catalyst slurry, some catalysts cannot be in contact with the reaction substances, and cannot produce catalytic effects, resulting in limited utilization of noble metal catalysts; such as the catalyst used in the patent US2006210867-A1 The direct attachment method is to mix palladium black Pd black catalyst nanoparticles with Nafion solution and deionized water in a certain proportion, ultrasonically oscillate evenly, drop them on the surface of the carbon substrate, and dry them with a heat lamp to prepare a flat electrode.

This method not only causes catalyst agglomeration but is not suitable for curved electrode surfaces

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