연료전지용 팔라듐-백금 코어-쉘 촉매의 제조방법

In the present invention hereinafter more particularly as one implementation of the SFC substrate.

The present invention refers to a passivated with a number (a) dissolved in an organic solvent mixed solution bath it sells step number;

(B) said inactive gas atmosphere to mix solution temperature palladium core nanoparticles sol mixed with the step number bath;

(C) said sol mixture by mixing step number platinum precursor solution bath;

(D) raising the temperature of the inactive gas atmosphere by said mixture palladium - platinum core - shell type nanoparticles step number bath;

(E) said palladium - platinum core - shell type nanoparticles adsorbed onto the carbon support palladium - platinum core - shell catalyst step number tank; and

(F) a step number in said palladium - platinum core - shell catalyst passivated with a number industry association;

A number of palladium platinum core - shell catalyst including method - high pressure liquid coolant therein.

The preferred embodiment of the present invention, said step (a) palladium precursor is sodium process for the date it sells (Na₂ PdCl₄ ), Potassium process for the date it sells (K₂ PdCl₄ ), Palladium chloride (PdCl₂ ) Preferably selected from least one during use. The product is used as an absorbent core by increasing activity of palladium present at the surface of platinum as well as platinum catalysts have to increase durability in addition existing well-known hydrogen fuel cell as redox catalysts can be greatly improves the activity per unit mass.

The preferred embodiment of the present invention, (a) said core nanoparticles in the colloidal nanoparticles passivated with a palladium bath serves number number number when surfactants added palladium with platinum nanoparticles over a core arranged without lumping core to nano-particles can be grown in the larger lattice constant of the, said method number prepared by the palladium - platinum core - shell nanoparticles in relatively low amounts by higher catalyst activity is also loading can be. Passivated with a number such as polyvinyl pyrrolidone (polyvinylpyrrolidone; PVP), sodium dodecyl sulfate (sodium dodecyl sulfate; SDS), polyethylene (polyethylene glycol; PEG) writing this call more than one can be selected among people.

The preferred embodiment of the present invention, (a) said number for palladium core nanoparticles in the organic solvent is high pressure liquid coolant capable of reducing these precursor reduction number while dissolving the solvent can be used if anything you can. This reduction is used as an organic solvent include ethylene writing this call number (ethylene glycol), 1, 3 - propane (1, 3 non-propanediol), pen hit die this year 1, 5 - (1, 5 a-pentadiol), die ethylene writing this call (diethylene glycol) can be selected from more than one people, preferably two or more in admixture used now. More preferably ethylene writing with this call by using ethylene Polyethylenglycol can die, the die 7:3 ratio the mixture is mixed ethylene said ethylene writing with this call now.

Said organic solvent is passivated with a dissolving palladium precursor and the extent to which the number is sufficient if positive of finds particular utility in a limited amount and not the. However palladium precursor 0. 17 Mmol, passivated with a number 0. 85 Mmol adding 10 ml when the organic solvent is preferably added.

The preferred embodiment of the present invention, (a) said number is passivated with a palladium precursor 1 mol in respect to 0. 1 - 10 Mol preferably by the addition of a. More preferably 0. 3 - 5. 0 Mol by the addition of a of a good ancestry. Polyvinyl pyrrolidone (PVP) is repeatedly disposed units exhibit when calculated on dry matter, is passivated with a 5 mol number can be added.

The preferred embodiment of the present invention, said step (b) can be performed in an inert gas atmosphere temperature rise temperature 100 - 300 °C 1 - 200 minutes. Most preferably palladium precursors in order to improve the temperature 200 °C temperature reduction reaction performed by a good ancestry synthesised palladium core nanoparticles 60 - 120 minutes. The number reduced from metals palladium precursor said inert gas by reducing the oxygen to prevent oxidation by air to serve for, as an example of such an inert gas nitrogen, helium, argon, neon, krypton, xenon, such as radon one of which can be selected from one gas.

The preferred embodiment of the present invention, said step (c) adding to the aqueous solution at ambient temperature for temperature is decreased and a platinum precursor used platinum precursors display process for the mote four [thu sodium (Na₂ PtCl₄ ), The display process for the mote four [thu potassium (K₂ PtCl₄ ), Platinum chloride (PtCl₂ ), Platinum chloride acid (H₂ PtCl₆ ) Preferably selected from least one during use.

The preferred embodiment of the present invention, step (c) said platinum in the precursors for palladium precursor 1 mol 0. 1 - 5 Mol can be mixing, the amount of platinum precursor 0. 1 Mol if sheet shell located spaced apart less than a high durability, the amount of platinum precursor 5 and vice versa. 0 Mol becomes more active when reducing the effects of weak electrical characteristics fixed core to be coated. Preferably 0. 5 - 2. 0 Mol comprising combining a good ancestry. Most preferably palladium precursor for 1 mol platinum precursor 1. 5 Mol comprising combining a good ancestry.

The preferred embodiment of the present invention, said (d) step can be performed under inert gas atmosphere temperature rise temperature 100 - 300 °C 1 - 200 minutes. Most preferably 110 - 160 °C temperature 90 - 150 minutes at a rate of 1 - 2 °C/min temperature rise performed palladium - platinum core - shell nanoparticles synthesised a good ancestry.

The preferred embodiment of the present invention, palladium platinum core - shell nanoparticles in an organic solvent (e)- said residue adsorbed onto the porous support oxygen enrichment process for high pressure liquid coolant hydrogen fuel cells can be used as catalyst support such supports number can be used if can be unbreakable. Preferably using carbon as a main component can be carbon support, said ket tsien carbon support and a carbon black (Ketjen Black Carbon), production cost can be selected using fullerene and carbon nanotube.

The preferred embodiment of the present invention, said (e) 10 - 60 weight % palladium - in contrast to platinum core - shell the nanoparticles are carbon support may be disclosed. The less than 10% by weight palladium - platinum core - shell nanoparticles if the activity of the catalyst component a predetermined carbon support is inadequate and brings, is more than 60% by weight free effect increasing the apparent effect of the activity of the catalyst, catalyst support component through a mechanical properties reduced equipment disclosed.

The preferred embodiment of the present invention, said step (f) using palladium - platinum core - shell catalyst through water and ethanol washed with organic solvents during the reaction can be a stand-alone number remaining passivated with a number, specifically at ambient temperature lowers the temperature, so that to obtain a nanoparticle solution nanoparticles does not create a deposit melts and then centrifuging the liquid solvent through the upper number to a stationary substrate. the acetone solvent (acetone), hexane (hexane) and toluene (toluen) can be selected from one or more than one, 20 - 30 minutes can be performed during the centrifuging is 3000 provided 4000 rpm.

The upper number is absorbed while the remaining precipitates are well melting which is volatile, the solvent can be water (water), ethanol (ethanol) and methanol (methanol) can be selected from one or more than one. These procedures by operation of passivated with a number number can be used for the organic solvent on a stand-alone. Even out under hydrogen atmosphere in a heat treatment time by number 200 °C is passivated with a palladium catalyst can be platinum core - shell - number number for reparing over high pressure liquid coolant.

The preferred embodiment of the present invention, palladium platinum core - shell catalyst particle size is 1 provided 10 nm - said may have uniform size.

the palladium - platinum core - shell catalyst mass uniformly sized each other through simple process, by reducing the number of valuable metals usage be fixed disclosed. In addition shell constituting epitaxy growth of platinum nanoparticles by maintaining spherical shape by lumping a wedge shape and the surface area of the catalytically active where X changes indicating equal to or less than.

Hereinafter the present invention is described more specifically based on a it should in the embodiment, the present invention defined by the next in the embodiment are not correct.

In the embodiment 1: platinum core - shell - palladium acetate

It sells sodium process for argon atmosphere date (0. 050 G, 0. 017 Mmol) on polyvinyl pyrrolidone (0. 0944 G, 0. 085 Mmol) writing this call ethylene (7 ml) ethylene writing this call die (3 ml) was heated at a temperature 200 °C 60 minutes after melting. Then display process for the mote four [thu sodium (Na₂ PtCl₄ ) 1. 5 Mol number mixed with heat temperature after 30 minutes in 20 ml acetone at ordinary temperature to determine a stand-alone added to the centrifuge and the supernatant after precipitation has surpassed its 4000 rpm, black precipitate dispersed in ethanol precipitation by adding acetone and behind the centrifuge and again with respect to the cyclohexane. This process after operation of dispersing a black precipitate palladium - platinum core - shell nanoparticles remaining ethanol solvent are obtained.

In the embodiment 2: - number of platinum core - shell catalyst palladium bath

Palladium - platinum core - shell nanoparticles prepared by the number by said in the embodiment 1 of hydrogen using a high pressure liquid coolant for fuel cell number was as redox catalysts. Said palladium - 60 weight % ethanol solution platinum core - shell the nanoparticles are carbon support distributed throughout a predetermined ultrasonic column into the reaction chamber. Then carbon supports chain ket tsien carbon black containing 5 to thereby elevate the reaction time or more after ultrasonic embodiment through the platinum core - shell nanoparticles adsorbed hydrogen carbon support containing palladium - catalyst for fuel cell number was high pressure liquid coolant.

Said catalyst for hydrogen fuel cells to ethanol with water flushing away of the catalyst after a codeword passivated with a number and a supernatant through a stand-alone number number lever alone, while the remaining material vacuum in a stand-alone completely number 2000. A further period of time in order to 200 °C atmosphere of a passivated with a stand-alone number number number number is passivated with hydrogen for reparing over a heat treatment is performed as redox catalysts for fuel cell number - of palladium catalyst was platinum core - shell high pressure liquid coolant

Experiment example 1: palladium - platinum core - shell nanoparticles transmission electron microscope analytic

By palladium platinum core - shell nanoparticles prepared by the number said in the embodiment 1 - 1 is shown to consist of an assortment of transmission electron microscope also result. (A) said of Figure 1 - shell nanoparticles of palladium nanoparticles is palladium - platinum core core material and low magnification transmission electron microscope photograph, (B) is palladium nanoparticles of platinum nanoparticles on epitaxial growth furnace (A) palladium - platinum core - shell nanoparticles and low magnification transmission electron microscope photograph synthesis, is saved in the high magnification transmission electron microscope photograph to fill are disclosed. (C) the spherical aberration is corrected by using a scanning type transmission electron microscope photographs taken and dark field phase, using the same mapping (D) is photo elements are disclosed.

As also shown in said 1 6. 0 ± 1. Palladium core nanoparticles of 1 nm have been synthesized, core nanoparticles on 7. 9 ± 1. 2 Nm of palladium - platinum core - shell nanoparticles can be schedulable know epitaxial growth furnace. In addition said in Figure 1 in high magnification transmission electron microscope photograph (B) through 0. Having a thickness of core 94 nm - shell nanoparticles can not inserted is synthesized. In addition said in Figure 1 (C) of scanning transmission electron microscope Image of the element mapping using dark field on palladium - platinum core - shell structures can be identifying through. Composition of an inductively coupled plasma atomic emission spectroscope platinum core - shell nanoparticles further palladium - (inductively coupled plasma atomic emission spectrometry, ICP non-AES) subject to analysis results, each atomic percent platinum palladium 39. 9%, 60. As 1% atomic ratio is 1:1. 51 Is also used for capable of nano particles is synthesized. These results indicate that the molar ratio of the reactants and adding a match without loss of organic metal precursor synthesis has been big.

Experiment example 2: palladium - platinum core - shell nanoparticles and shape of the structural change analysis

Palladium - platinum catalyst carried on carbon support of said in the embodiment 2 - core shell nanoparticles by observation under transmission electron microscope to confirm the result when the palladium - platinum core - shell 2 also shown to change and shape of the nanoparticles.

The carbon carrier chain ket tsien black carbon - carbon support said in the embodiment 2 using palladium platinum core - shell nanoparticles when palladium - platinum core - shell structure and shape of the room change adsorbing grain structure, many times under atmosphere of hydrogen passivated with hydrogen fuel cell catalyst washed a preform in a stand-alone were any changes after a number number no confirm it.

Experiment example 3: palladium - platinum core - shell catalyst circulation voltage - current measurement

Platinum core - shell nanoparticles containing palladium prepared by the number by said in the embodiment 2 - 5 mg Nafion perfluorinated ion-a exchange resin (Aldrich Co.) 0 and inward for redox catalysts. 10 Minutes into a 10 ml distilled water 1 ml is placed ultrasonic chatter. L solution using carbon electrode surface has been introducing positive number be 5 micro syringe. The electrode core - shell at a 3 mm diameter platinum palladium - ink prior to making the vibration region 70 °C heated in an oven to impair both very dry.

Circulation is provided to convert carbon working electrode voltage - current method before three (3 mm diameter disk, BAS), platinum counter electrode (0. 5 Mm diameter 5 cm length line, BAS), - having the chloride reference electrode (Ag/AgCl in saturated NaCl), Autolab (PGSTAT 10, Eco Chemie, Netherlands) was performed using electrochemical analysis machine. 1. 0 M of using, saturated nitrogen atmosphere to 20 mV/s PLR -0 forms. 2 V - 1. 0 V in range of voltages between a were measured.

Number by said in the embodiment 2 - core - shell nanoparticles as redox catalysts containing platinum palladium produced therewith inward for circulation of the reaction surface area measurement and the current - voltage current at 3 also results have shown. As also shown in said 3 - hydrogen fuel cell catalyst containing palladium platinum core - shell nanoparticles (filar) (Johnson Matthey catalyst) (dashed lines) relative to the reaction surface is a commercial catalyst 1. 8 Times were confirm that having a small surface.

Experiment example 4: palladium - platinum core - shell catalyst oxygen reduction reaction activity monitoring

Experimental example 3 - high pressure liquid coolant in said palladium platinum core - shell 5 micro l number using carbon electrode surface with respect to the syringe into an ink. The electrode core - shell at a 3 mm diameter platinum palladium - ink prior to making the vibration region 70 °C heated in an oven to impair both very dry.

1 Oxygen reduction reaction activity of the measurements. 0 M of using, saturated oxygen atmosphere and has the potential difference of 10 mV/s 0. 2 V - 1. 0 V in range of voltages between a were measured. The working electrode catalyst opposite that of the 400 rpm, 900 rpm, 1600 rpm, 2500 rpm, and 3600 rpm is provided to automatically oxygen reduction reaction activity as a result 0. 9 V per unit area per unit mass activity can be obtained in kinetic activity.

Platinum core - shell nanoparticles containing palladium prepared by the number by said in the embodiment 2 - hydrogen fuel cell catalyst of 0. 9 V 4 active per unit mass per unit area also have shown to result in kinetic activity.

Said Figure 4 - core - shell nanoparticles including platinum palladium catalyst with a commercial of catalyst for 0. 9 V active per unit area per unit mass (solid bar graph) in kinetic and revealing the secret key is active (single tissue), hydrogen fuel cell catalyst containing palladium - platinum core - shell nanoparticles through commercial catalyst kinetic activity per unit mass per unit area for each active 2. 9 Times, 2. 2 Highly binders heretofore been can be ascertained. Said number is passivated with a uniform size is composed of palladium platinum core - shell catalyst is good electrochemical properties - number for reparing over and showing that catalytic activity can be identified.

Experiment example 5: measuring durability of palladium - platinum core - shell catalyst

Experimental example 3 - high pressure liquid coolant in said palladium platinum core - shell 5 micro l number using carbon electrode surface with respect to the syringe into an ink. The electrode core - shell at a 3 mm diameter platinum palladium - ink prior to making the vibration region 70 °C heated in an oven to impair both very dry.

The method for measuring durability as catalyst oxygen reduction 0. 6 V - 1. 1 V (vs. Standard hydrogen electrode) voltage range of 20000 times after circulating nitrogen saturated 1. 0 M of using, and has the potential difference of 20 mV/s -0. 2 V - 1. 0 V - circulated in voltage range of voltages between a catalytic reaction surface area measurement and 5a also results have shown the current method.

In addition catalyst for commercial manner after storing the measuring result to 6000 times measuring circulating durability also 5b shown. As a result said hydrogen fuel cell catalyst containing palladium - platinum core - shell nanoparticles (filar) (dashed lines) said reaction surface variation in commercial catalyst were less than the door frame. Also same 5c such as palladium - platinum core - shell nanoparticle catalyst reaction surface is represented by graph result reduced durability experiment result of reducing catalyst for commercial but 17% 67% were confirmed. Through said palladium - platinum core - shell catalyst catalytically active tube as well as good electrochemical properties can be know.

the palladium - platinum core - shell catalyst electrochemical properties through simple process has been show good catalytic activity, in particular, 10 nm hereinafter relative to existing reported catalyst of platinum nanoparticles has uniformly sized shell constituting epitaxy growth maintains shape and spherical shape of the surface area of the front light with high efficiency by lumping changes of fuel cell catalyst are expected development plays an important role.