WO2008003225A1 - A catalyst slurry and the preparation method of the same - Google Patents

Abstract

A catalyst slurry, which comprises solid catalyst particle 1-40wt%, high molecular polymer proton conductor 1-40 wt%, water 0.1-50 wt% and ethanol 1-50 wt% and further comprises 1-90wt% organic acid. A preparation method of the catalyst slurry, which comprises the steps of preparing the dispersion liquid of high molecular polymer proton conductor and preparing the catalyst slurry and etc. The property of the electrode prepared by the catalyst slurry according to the present invention is superior to that of the electrode prepared by the catalyst slurry according to the current technology. Furthermore, the preparation of the catalyst slurry according to the present invention is convenient and the cost and energy-consuming are reduced.

Description

 Catalyst slurry and preparation method thereof

 The present invention relates to a catalyst and a process for the preparation thereof, and more particularly to a catalyst paddle and a method of preparing the same. Background technique

 The catalyst coating on the fuel cell membrane electrode is prepared by dispersing a solid particulate catalyst in a solvent to prepare a catalyst slurry, applying the slurry to a proton exchange membrane, and then drying the film into a film. The performance of the catalyst slurry directly affects the performance of the membrane electrode produced, and ultimately affects the power generation performance of the fuel cell.

 A catalyst slurry is given in the European patent EP 0 955 687 A2, mainly by adding an aqueous solution of Nafion alcohol produced by Dupont, USA, to MOH, a solution of H+ form Nafion to M+, and then using a high boiling polar solvent to produce Dupont. The Nafion alcohol aqueous solution was evaporated and replaced, then a catalyst was added, stirred to form a slurry, dried on a diffusion layer to form a catalyst layer, and then placed in an acid to convert Na+ of Nafion to H+. It can be seen that the electrode fabrication process is very complicated.

 A catalyst slurry is given in PCT/US2003/033133, the first solvent in the slurry being water and the second solvent being a polar aprotic solvent such as hydrazine, hydrazine, hydrazine-dimethylformamide, hydrazine, hydrazine. - High boiling point solvents such as dimethylacetamide, DMSO, and acetonitrile. This slurry ensures that the electrode will not burn when dried at 80 to 140 °C.

 In general, the solvent for preparing the catalyst slurry includes water and an organic solvent such as an alcohol, an ether, an ester, a ketone, and a high-boiling hydrazine, hydrazine, hydrazine-dimethylformamide, N,N-dimethylacetamide, DMSO, Acetonitrile and the like.

 The solid polymer proton conductor for the preparation of the catalyst slurry, such as Nafion manufactured by Dupont, is generally dissolved in a solution of water and alcohol. If the catalyst is separately added to the solution for stirring and mixing, the catalyst and Nafion in the prepared catalyst slurry cannot be effectively dispersed and combined, which affects the direct application of the catalyst to the CCM fuel cell member, thereby affecting the electrode performance of the battery.

The method of solvent replacement of Nafion/water and alcohol solution is time consuming, energy consuming, and very troublesome. Moreover, most of the solvents are organic solvents, which are relatively toxic and require a relatively high operating environment. Summary of the invention

 SUMMARY OF THE INVENTION An object of the present invention is to provide a catalyst paddle and a method of preparing the same in order to solve the above problems.

 The object of the present invention is achieved by a catalyst slurry comprising solid catalyst particles of 1 to 40% by weight, a polymer polymer proton conductor of 1 to 40% by weight, a water of 0.1 to 50% by weight, and an alcohol of 1 to 50% by weight. In addition, it also contains organic acid l~90%wt.

 The solid catalyst particles are solid catalyst particles containing platinum.

 The high molecular polymer proton conductor is selected from the group consisting of a perfluorosulfonic acid resin, a sulfonated trifluorostyrene resin, a polymethylphenylsulfonic acid silicone resin, a sulfonated polyetheretherketone resin, and a sulfonated polystyrene. Polyethylene copolymer resin and sulfonated polystyrene-polyethylene/butene-polystyrene resin.

The organic acid is selected from one or more of a -COOH group-containing or -S0 ₃ H group-containing organic acid.

 The organic acid containing a -COOH group includes formic acid, acetic acid, acrylic acid, succinic acid, oxalic acid, malic acid, EDTA.

 The alcohol is one or more selected from the group consisting of methanol, ethanol, ethylene glycol, propanol, isopropanol, and glycerin.

 A method for preparing a catalyst slurry, wherein the solid catalyst particles are 1 to 40% by weight, the polymer polymer proton conductor is 1 to 40% by weight, the organic acid is 1 to 90% by weight, the water is 0.1 to 50% by weight, and the alcohol is 1 to 50. %wt is the basic material and is prepared by the following steps:

 a, making a dispersion of polymer polymer proton conductor:

 The polymer polymer proton conductor is mixed with 1 to 40% by weight, 0.1 to 50% by weight of water and 1 to 50% by weight of alcohol, placed in an autoclave, sealed, heated, and continuously stirred for 3 hours, and then cooled to be high. a dispersion of molecular polymer proton conductors;

 b. Making catalyst slurry:

 The solid catalyst particles 1 to 40% by weight, the organic acid 1 to 90% by weight, and the dispersion of the polymer-polymeric substance sub-conductor obtained in the step a were mixed together and shaken by ultrasonic waves to prepare a catalyst slurry.

The solid catalyst particles are platinum-containing solid catalyst particles; the polymer polymer proton conductor is selected from the group consisting of a perfluorosulfonic acid resin, a sulfonated trifluorostyrene resin, and a polymethylphenylsulfonate silicone resin. a sulfonated polyetheretherketone resin, a sulfonated polystyrene-polyethylene copolymer resin, and a sulfonated polystyrene-polyethylene/butylene-polystyrene resin; the organic acid is selected from a -COOH group or Contains - S0 ₃ H One or more of the organic acids; the alcohol is selected from one or more of methanol, ethanol, ethylene glycol, propanol, isopropanol, and glycerin.

 The organic acid containing a -COOH group includes formic acid, acetic acid, propionic acid, succinic acid, oxalic acid, malic acid, EDTA.

 The invention provides an effective formula of a fuel cell catalyst slurry, which is not only easy to prepare, simple, saves time and labor, environmental pollution is relatively small, and the prepared electrode has better performance. detailed description

 Example 1

 Take HP40% Pt/C catalyst produced by O.lg E-TEK, add 2g acetic acid, ultrasonically shake for 5min, and add Nafion DE 520 dispersion produced by Dupont Company (the concentration of perfluorosulfonic acid resin in the dispersion is 5.4%) The solvent contains 45 to 48% of water, 45 to 48% of 1-propanol, less than 4% of ethylene glycol, less than 1% of mixed ethers, 0.7 g, ultrasonically shaken for 5 min, and continuously stirred. That is, a catalyst slurry of the present invention is obtained.

 Example 2

 Mixing perfluorosulfonic acid resin lg, water 4g and ethanol 5g, placing in an autoclave, sealing, heating to 250 ° C, and stirring for 3 hours, cooling to obtain a dispersion of polymer proton conductor;

 Take HP40°/ produced by O.lg E-TEK. Pt/C, lg oxalic acid was added, ultrasonically shaken for 5 min, 0.5 g of the above dispersion was added, ultrasonically shaken for 5 min, and stirring was continued. Namely, a catalyst slurry of the present invention is obtained.

 Example 3

 The sulfonated trifluorostyrene resin lg, water 3g and 1-propanol 6g are mixed, placed in an autoclave, sealed, heated, and continuously stirred for 3 hours, and then cooled to obtain a dispersion of the polymer polymer proton conductor; Together with ultrasonic vibration, a dispersion of a polymer proton conductor is prepared; and HP 40°/ produced by O. lg E-TEK. Pt/C, 3 g of oxalic acid was added, ultrasonically shaken for 5 min, 0.6 g of the above dispersion was added, ultrasonically shaken for 5 min, and stirring was continued. Namely, a catalyst slurry of the present invention is obtained.

 Example 4

1.5 g of polymethylphenylsulfonic acid siloxane resin, 5 g of water and 8.5 g of ethylene glycol were mixed, and the kettle was charged. Heating, cooling, and dispersing a polymer polymer proton conductor;

 Take HP40°/ produced by O.lg E-TEK. Pt/C, 4 g of succinic acid was added, ultrasonically shaken for 5 min, 0.8 g of the above dispersion was added, ultrasonically shaken for 5 min, and stirring was continued. Namely, a catalyst slurry of the present invention is obtained.

 Comparative Test

 Take 0.1g E-TEK40%Pt/C, add 2g water, ultrasonically shake for 5min, add 0.7g of Nafion DE 520 dispersion produced by Dupont Company, shake it for 5min, stir continuously, put the slurry into the oven, The volatile alcohol solvent in the slurry was evaporated at 60 ° C, and stirring was continued. The water was replenished in time to maintain the weight of the catalyst slurry at 2.9 g. After 6 hours, the majority of the slurry was volatility with water. After the solvent is volatilized, an aqueous catalyst slurry used in the prior art is obtained.

 The catalyst slurry obtained in Example 1 was numbered 1, and the catalyst slurry obtained in the comparative test was numbered 2, which were used to prepare electrodes, respectively. The specific operation was as follows - taking Nafion 211 produced by DUPONT Co., Ltd., and cutting 70 x 70 mm of two For the film, one of the films is taken, and the above-mentioned catalyst slurry No. 1 is sprayed on both sides of the film by a spray gun. During the spraying process, the solvent in the catalyst slurry is quickly evaporated and dried by using 130 to 150 Torr of hot air. Another film was taken, and the above-mentioned catalyst slurry No. 2 was sprayed onto both sides of the film by a paint pen. During the spraying, the solvent in the catalyst slurry was quickly volatilized and dried by hot air at 130 to 150 °C. The CCM electrode prepared by the CCM electrode (No.: 1#) prepared in the No. 1 catalyst slurry and the No. 2 catalyst slurry (number: 2# is sandwiched between two SGL companies of 50 g 50 mm SGL) Between 30BC, the black side with toner faces the CCM membrane electrode.

The above electrodes were placed in a fuel cell electrode holder for testing, wherein the test conditions were as follows: Battery operating temperature: 60 ° C; H ₂ : 80 RH%, metering ratio 1.1; Air: 50 RH%, metering ratio 3.5; Hydrogen and air The outlet pressure is atmospheric pressure.

 The test results are shown in Table 1.

 Table 1

从表 1的测试结果可以看出：采用本发明的催化剂浆料所制得的 1#电极 的发电性能明显高于对比试验催化剂装料所制得的 2#电极，而且本发明所提 供的催化剂浆料配方操作非常方便， 省时省力， 耗能少。

It can be seen from the test results of Table 1 that the power generation performance of the 1# electrode prepared by using the catalyst slurry of the present invention is significantly higher than that of the 2# electrode prepared by the comparative test catalyst charge, and the catalyst provided by the present invention. The slurry formulation is very convenient to operate, saves time and effort, and consumes less energy.

Claims

The invention relates to a catalyst slurry comprising: 1 to 40% by weight of solid catalyst particles, 1 to 40% by weight of polymer proton conductor, 0.1 to 50% by weight of water and 1 to 50% by weight of alcohol, characterized in that: Also included are organic acids 1 to 90% by weight. The catalyst slurry according to claim 1, wherein the solid catalyst particles 'is platinum-containing solid catalyst particles. The catalyst slurry according to claim 1, wherein the polymer polymer proton conductor is selected from the group consisting of perfluorosulfonic acid resin, sulfonated trifluorostyrene resin, and polymethylphenylsulfonic acid silicon oxide. An alkane resin, a sulfonated polyetheretherketone resin, a sulfonated polystyrene-polyethylene copolymer resin, and a sulfonated polystyrene-polyethylene/butylene-polystyrene resin. The catalyst slurry according to claim 1, wherein the organic acid is one or more selected from the group consisting of a -COOH group or an organic acid containing a -SO ₃ H group. The catalyst slurry according to claim 4, wherein the -COOH group-containing organic acid comprises formic acid, acetic acid, acrylic acid, succinic acid, oxalic acid, malic acid, EDTA. The catalyst slurry according to claim 1, wherein the alcohol is one or more selected from the group consisting of methanol, ethanol, ethylene glycol, propanol, isopropanol, and glycerin. A method for preparing a catalyst slurry, characterized in that the solid catalyst particles are from 1 to 40% by weight, and the polymer polymer proton conductor is from 1 to 40 °/. Wt, organic acid l~90%wt, water 0.1~50%wt and alcohol l~50%wt as the basic raw materials, prepared by the following steps:  a. preparing a dispersion of a polymer polymer proton conductor - mixing the polymer polymer proton conductor 1 to 40% by weight, 0.1 to 50% by weight of water, and 1 to 50% by weight of the alcohol, and placing it in an autoclave, sealing, Heating, and stirring for 3 hours, after cooling, the dispersion of polymer proton conductor;  b. Making catalyst slurry:  The solid catalyst particles are l~40°/. Wt, organic acid l~90°/. The dispersion of the high molecular polymer proton conductor obtained by the wt and the step a is mixed together and shaken by ultrasonic waves, and continuously stirred to prepare a catalyst slurry. The method for preparing a catalyst slurry according to claim 7, wherein: the solid The catalyst particles are platinum-containing solid catalyst particles; the polymer polymer proton conductor is selected from the group consisting of perfluorosulfonic acid resin, sulfonated trifluorostyrene resin, polymethylphenylsulfonate siloxane resin, sulfonated poly An ether ether ketone resin, a sulfonated polystyrene-polyethylene copolymer resin, and a sulfonated polystyrene-polyethylene/butene-polystyrene resin; the organic acid is selected from a -COOH-containing group or contains -S0 ₃ One or more of the H-based organic acids; the alcohol is selected from one or more of methanol, ethanol, ethylene glycol, propanol, isopropanol, and glycerin. The method for preparing a catalyst slurry according to claim 8, wherein the -COOH group-containing organic acid comprises formic acid, acetic acid, acrylic acid, succinic acid, oxalic acid, malic acid, and EDTA.