CN103219528A - Direct formic acid fuel cell anode catalyst and preparation method of catalyst - Google Patents

Abstract

The invention relates to a fuel cell catalyst and a preparation method of the catalyst, and particularly relates to a direct formic acid fuel cell anode catalyst and a preparation method of the fuel cell catalyst. The direct formic acid fuel cell anode catalyst is a Pd/ITO-CNTs catalyst, wherein the Pd is loaded on an ITO-CNTs carrier. The preparation method comprises the steps of weighting ITO and carbon nanotubes in the mixed solution of glycol and isopropanol, and dissolving PdCl2 solid into glycol solution; mixing the two solutions, and then adjusting pH value to be 8 to 11; carrying out microwave heating to 140 to 160 DEG C in the presence of inert gas; cooling to room temperature, adjusting pH value to be 3 to 4, and stirring for 8 to 12 hours; and carrying out extraction filtering, washing and drying to obtain the Pd/ITO-CNTs catalyst. By using ITO as the carrier, the corrosion resistance and oxidant resistance of the carrier are improved; the conductivity of the carrier is improved by embedding ITO into the lattice of In2O3 through Sn ions; and the conductivity of the carrier is further improved by adding nanotubes into the carrier.

Description

Direct aminic acid fuel battery anode catalyst and preparation method thereof

Technical field

The present invention relates to a kind of fuel-cell catalyst and preparation method thereof, relate in particular to a kind of direct aminic acid fuel battery anode catalyst and preparation method thereof.

Background technology

Directly aminic acid fuel battery can be used for removable power supply and miniaturization power supply, have broad application prospects, yet the Pd catalyst that is used for direct aminic acid fuel battery, stability is good inadequately, performance significantly descends after the long-time running, wherein the performance of carrier directly has influence on the stable and active of catalyst, and present typical application fuel-cell catalyst carrier the most widely is Vulcan XC-72, but this material with carbon element is corroded under the operation of fuel cells environment easily.Strengthen the resistance to corrosion of carbon carrier, seeking more stable carrier material becomes one of important channel of improving catalyst stability.

Summary of the invention

For conductivity and the resistance to corrosion that improves carrier, raising is to the electro catalytic activity of formic acid oxidation, increase anti-formic acid oxidation intermediate, poisoning capability as materials such as CO, improve stability, the durability of catalyst, the invention provides a kind of direct aminic acid fuel battery anode catalyst and preparation method thereof.

Direct aminic acid fuel battery anode catalyst of the present invention is the Pd/ITO-CNTs catalyst, and Pd is loaded on the ITO-CNTs carrier, wherein: the Pd carrying capacity is 5 ~ 40% of a catalyst quality, and the content of carbon nano-tube is 30～60% of carrier quality.

Direct aminic acid fuel battery anode catalyst preparation process of the present invention is as follows:

(1) take by weighing a certain amount of ITO and carbon nano-tube and join in ethylene glycol and the isopropyl alcohol mixture, ultrasonic wave disperses 0.5 ~ 3h, and wherein the volume ratio of carrier quality and mixed solution is 1.0 ~ 2.0 mg/ml, and the content of carbon nano-tube is 30～60% of carrier quality;

(2) with PdCl ₂Solid dissolves in the ethylene glycol solution, PdCl ₂Concentration is 0.26 ~ 2.08mg/ml, fully stirs;

(3) above-mentioned two kinds of solution are mixed, control Pd carrying capacity is 5 ~ 40% of a catalyst quality, the powerful 3 ~ 5h that stirs, and regulator solution pH is 8 ~ 11 then;

(4) feed the high-purity inert gas and get rid of oxygen in the solution, and under the protection of inert gas, microwave heating to 140 ~ 160 ℃;

(5) be cooled to room temperature then, regulate pH between 3 ~ 4, stir 8 ~ 12h;

(6) with after a large amount of deionized water suction filtrations, the washing, dry 3 ~ 5h obtains the Pd/ITO-CNTs catalyst in vacuum drying chamber.

The present invention proposes to utilize indium tin oxide (ITO) and carbon nano-tube (CNTs) to mix as the direct aminic acid fuel battery anode catalyst of preparing carriers first.Adopt ITO to make carrier, improved the anticorrosive and oxidation resistance of carrier, again because ITO is by Sn ion embed oxide In ₂O ₃Lattice in, improved conductivity, simultaneously in carrier, add carbon nano-tube again, further improve the conductivity of carrier.

Pd/ITO-CNTs catalyst of the present invention significantly improves with respect to Pd/CNTs and Pd/ITO the activity and the stability of formic acid electroxidation, the oxidation peak current density of just sweeping of formic acid is 2.32 times of Pd/ITO on the Pd/ITO-CNTs catalyst, be 1.51 times of Pd/CNTs, behind the aging 500 circle loop tests on the Pd/ITO-CNTs catalyst formic acid just sweeping oxidation peak current density and only decayed 14%, decayed 31% and 56% respectively on Pd/ITO and the Pd/CNTs catalyst.

Description of drawings

(1) Fig. 1 is the XRD spectra of Pd/ITO-CNTs catalyst and the carrier ITO of different content CNTs;

(2) Fig. 2 is containing 0.5 mol L for the Pd/ITO-CNTs catalyst of different content CNTs ^-1HCOOH and 0.5 mol L ^-1H ₂SO ₄Cyclic voltammetry curve in the mixed solution;

(3) Fig. 3 is just sweeping oxidation peak current density normalized curve for the Pd/ITO-CNTs catalyst of different content CNTs at scan round 500 circle back formic acid.

Embodiment

The present invention is further illustrated below in conjunction with accompanying drawing, but do not limit to so, every technical solution of the present invention is made amendment or is equal to replacement, and do not break away from the spirit and scope of technical solution of the present invention, all should be encompassed in protection scope of the present invention.

Embodiment one: the direct aminic acid fuel battery anode catalyst preparation process of present embodiment is as follows:

(1) taking by weighing a certain amount of ITO and carbon nano-tube joins in ethylene glycol and the isopropyl alcohol mixture, ultrasonic wave disperses 0.5 ~ 3h, wherein ethylene glycol and isopropyl alcohol volume ratio are 2:1 ~ 8:1, the volume ratio of carrier quality and mixed solution is 1.0 ~ 2.0 mg/ml, and the content of carbon nano-tube is 30～60% of carrier quality;

(2) with PdCl ₂Solid dissolves in the ethylene glycol solution, PdCl ₂Concentration is 0.26 ~ 2.08mg/ml, fully stirs;

(3) above-mentioned two kinds of solution are mixed, control Pd carrying capacity is 5 ~ 40% of a catalyst quality, and the powerful 3 ~ 5h that stirs drips 0.5 ~ 1.0 molL then ^-1The ethylene glycol solution of NaOH is 8 ~ 11 with regulator solution pH;

(4) feed the high-purity inert gas 20 minutes of purity 99.99%, get rid of the oxygen in the solution, and under the protection of inert gas, microwave heating to 140 ~ 160 ℃;

(5) be cooled to room temperature then, with 0.5 ~ 1.0 molL ^-1HNO ₃Regulate pH between 3 ~ 4, stir 8 ~ 12h;

(6) with after a large amount of deionized water suction filtrations, the washing, 80 ℃ of drying 3 ~ 5h of constant temperature obtain the Pd/ITO-CNTs catalyst in vacuum drying chamber.

Embodiment two: what present embodiment and embodiment one were different is that the Pd carrying capacity is respectively 5%, 10%, 20%, 30%, 40% of catalyst quality.

Embodiment three: the direct aminic acid fuel battery anode catalyst preparation process of present embodiment is as follows:

(1) taking by weighing the common 50mg of a certain amount of ITO and carbon nano-tube joins in 20mL ethylene glycol and 5mL isopropyl alcohol (ethylene glycol and isopropyl alcohol volume ratio the are 4:1) mixed solution, ultrasonic wave disperses 1 h, and wherein the content of carbon nano-tube is respectively 0%, 30%, 40%, 50%, 60%, 100% of carrier gross mass.

(2) with the PdCl of 20.8mg ₂Solid dissolves in (the theoretical carrying capacity of the Pd of prepared catalyst is 20wt%) in the ethylene glycol solution of 20mL, fully stirs.

(3) with after two kinds of solution mixing, the powerful 3h that stirs drips 1molL then ^-1The ethylene glycol solution of NaOH is about 10 with regulator solution pH.

(4) fed high-purity argon 20 minutes, get rid of the oxygen in the solution, and under the protection of argon gas, put into microwave oven microwave heating 40 ~ 60s, make its reaction temperature reach 140 ~ 160 ℃.

(5) be cooled to room temperature, use 1molL ^-1HNO ₃Regulate pH between 3 ~ 4, stir a night.

(6) with after a large amount of deionized water suction filtrations, the washing, 80 ℃ of dry 3h of constant temperature in vacuum drying chamber obtain the Pd/ITO-CNTs catalyst of the CNTs of different content.

Fig. 1 is the XRD spectra of Pd/ITO-CNTs catalyst and the carrier ITO of different content CNTs, finds that from figure the diffraction maximum of Pd and ITO, CNTs exists simultaneously in the Pd/ITO-CNTs catalyst, and Pd exists with face-centred cubic structure.

Fig. 2 is containing 0.5mol L for the Pd/ITO-CNTs catalyst of different content CNTs ^-1HCOOH and 0.5mol L ^-1H ₂SO ₄Cyclic voltammetry curve in the mixed solution; Formic acid is just being swept oxidation peak current density Pd/ITO-CNTs50%〉Pd/ITO-CNTs40% 〉 Pd/ITO-CNTs60%〉Pd/ITO-CNTs 30% 〉 Pd/CNTs〉Pd/ITO.Show that the Pd/ITO-CNTs catalyst significantly improves with respect to Pd/CNTs and Pd/ITO catalyst the formic acid catalytic oxidization activity.

Fig. 3 is just sweeping oxidation peak current density normalized curve for the Pd/ITO-CNTs catalyst of different content CNTs at scan round 500 circle back formic acid, behind scan round 500 circles, formic acid is just being swept speed Pd/ITO-CNTs50%＜Pd/ITO-CNTs40%＜Pd/ITO＜Pd/ITO-CNTs30%＜Pd/ITO-CNTs 60%＜Pd/CNTs of oxidation peak current density decay.Show that the Pd/ITO-CNTs50% catalyst stability is best.

Claims (10)

1. direct aminic acid fuel battery anode catalyst, it is characterized in that described catalyst is the Pd/ITO-CNTs catalyst, Pd is loaded on the ITO-CNTs carrier, wherein: the Pd carrying capacity is 5 ~ 40% of a catalyst quality, and the content of carbon nano-tube is 30～60% of carrier quality.

2. direct aminic acid fuel battery anode catalyst according to claim 1 is characterized in that described Pd carrying capacity is 10% of a catalyst quality.

3. direct aminic acid fuel battery anode catalyst according to claim 1 is characterized in that described Pd carrying capacity is 20% of a catalyst quality.

4. direct aminic acid fuel battery anode catalyst according to claim 1 is characterized in that described Pd carrying capacity is 30% of a catalyst quality.

5. direct aminic acid fuel battery anode catalyst according to claim 1, the content that it is characterized in that described carbon nano-tube is 30% of carrier quality.

6. direct aminic acid fuel battery anode catalyst according to claim 1, the content that it is characterized in that described carbon nano-tube is 40% of carrier quality.

7. direct aminic acid fuel battery anode catalyst according to claim 1, the content that it is characterized in that described carbon nano-tube is 50% of carrier quality.

8. direct aminic acid fuel battery anode catalyst according to claim 1, the content that it is characterized in that described carbon nano-tube is 60% of carrier quality.

9. the preparation method of a direct aminic acid fuel battery anode catalyst is characterized in that described method step is as follows:

(1) take by weighing a certain amount of ITO and carbon nano-tube and join in ethylene glycol and the isopropyl alcohol mixture, ultrasonic wave disperses 0.5 ~ 3h, and wherein the volume ratio of carrier quality and mixed solution is 1.0 ~ 2.0 mg/ml, and the content of carbon nano-tube is 30～60% of carrier quality;

(2) with PdCl ₂Solid dissolves in the ethylene glycol solution, PdCl ₂Concentration is 0.26 ~ 2.08mg/ml, fully stirs;

(3) above-mentioned two kinds of solution are mixed, control Pd carrying capacity is 5 ~ 40% of a catalyst quality, the powerful 3 ~ 5h that stirs, and regulator solution pH is 8 ~ 11 then;

(4) feed the high-purity inert gas and get rid of oxygen in the solution, and under the protection of inert gas, microwave heating to 140 ~ 160 ℃;

(5) be cooled to room temperature then, regulate pH between 3 ~ 4, stir 8 ~ 12h;

(6) with after a large amount of deionized water suction filtrations, the washing, dry 3 ~ 5h obtains the Pd/ITO-CNTs catalyst in vacuum drying chamber.

10. the preparation method of direct aminic acid fuel battery anode catalyst according to claim 9 is characterized in that described ethylene glycol and isopropyl alcohol volume ratio are 2:1 ~ 8:1.

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