阅读说明：本技术 一种增强硼氢根直接氧化的多孔微球镍基催化剂 (Porous microsphere nickel-based catalyst for enhancing direct oxidation of borohydride ) 是由 余丹梅 胡毕豪 徐川岚 胡兵兵 陈鹏 于晶晶 陈昌国 刘渝萍 于 2019-09-25 设计创作，主要内容包括：一种增强硼氢根直接氧化的多孔微球镍基催化剂,其特征是：(1)常温常压下,配制0.2mol dm<Sup>-3</Sup>的氯化镍(NiCl<Sub>2</Sub>·6H<Sub>2</Sub>O)与4.5mol dm<Sup>-3</Sup>氯化铵(NH<Sub>4</Sub>Cl)的电沉积液；(2)将打磨光滑的1cm×2cmNi片作为工作电极,碳条为辅助电极,饱和甘汞电极为参比电极装配成三电极体系；(3)在298.15K下,采取脉冲电压沉积法制备镍基催化剂,制备条件：高电压-0.3V～0V、低电压-1.7V,占空比50％、频率25mHz、沉积时间750s。脉冲电压沉积法制备的镍基催化剂以其特殊的结构形貌,显著增加了比表面积,从而增多了催化位点,降低了<Image he="83" wi="111" file="DDA0002214896190000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>直接氧化的电荷传质阻力,增强了反应活性,提高了燃料利用率。同时,特殊的结构形貌也改善了催化剂的稳定性,显著提升了直接硼氢燃料电池的性能。(A porous microsphere nickel-based catalyst for enhancing direct oxidation of borohydride is characterized in that: (1) preparing 0.2mol dm under normal temperature and pressure ‑3 Nickel chloride (NiCl) 2 ·6H 2 O) and 4.5mol dm ‑3 Ammonium chloride (NH) 4 Cl); (2) a polished smooth 1cm multiplied by 2cm Ni sheet is used as a working electrode, a carbon strip is used as an auxiliary electrode, and a saturated calomel electrode is used as a reference electrode to assemble a three-electrode system; (3) preparing a nickel-based catalyst by adopting a pulse voltage deposition method under 298.15K, wherein the preparation conditions are as follows: high voltage of-0.3V to 0V, low voltage of-1.7V, duty ratio of 50 percent, frequency of 25mHz and deposition time of 750 s. The nickel-based catalyst prepared by the pulse voltage deposition method has the special structural appearance, and the specific surface area is obviously increased, so that the catalytic sites are increased, and the catalytic sites are reduced The charge mass transfer resistance of direct oxidation enhances the reaction activity and improves the fuel utilization rate. Meanwhile, the special structural morphology also improves the stability of the catalyst, and obviously improves the performance of the direct borohydride fuel cell.)

1. A porous microsphere nickel-based catalyst for enhancing direct oxidation of borohydride is characterized by being prepared by the following method:

(1) preparing 0.2mol dm under normal temperature and pressure^-3Nickel chloride (NiCl)₂·6H₂O) and 4.5mol dm^-3Ammonium chloride (NH)₄Cl);

(2) a smooth 1cm multiplied by 2cm Ni piece is taken as a working electrode, a carbon strip is taken as an auxiliary electrode, and a saturated calomel electrode is taken as a reference electrode to assemble a three-electrode system;

(3) preparing a nickel-based catalyst by adopting a pulse voltage deposition method under 298.15K, wherein the preparation conditions are as follows: high voltage of-0.3V to 0V, low voltage of-1.7V, duty ratio of 50 percent, frequency of 25mHz and deposition time of 750 s.

Technical Field

The invention belongs to the field of electrochemical application, and particularly relates to a method for preparing catalytic hydroboration radicals by a pulse voltage electrodeposition methodA direct oxidation nickel-based catalyst, and

is the negative active material of a Direct Borohydride Fuel Cell (DBFC), namely the fuel of the cell.

Background

DBFC is a group of compounds produced by direct oxidation

The chemical energy of the energy conversion device is directly converted into electric energy. Compared with the traditional hydrogen-oxygen fuel cell, the DBFC has higher cell voltage, higher specific capacity and energy conversion efficiency. In addition, the borohydride can stably exist in a solid or liquid form at normal temperature and normal pressure, so that the problems of inconvenient transportation and storage and the like of the traditional hydrogen source are avoided. Meanwhile, borohydride also belongs to a class of compounds with the highest hydrogen storage capacity, and is a good hydrogen source. However, the research in recent years finds that the method has the following problems: the catalyst is in catalysis

The hydrolysis reaction of the catalyst can be catalyzed while the catalyst is directly oxidized, so that the utilization rate of the fuel is reduced; ②

Easily penetrated septum or fixationThe body electrolyte layer and the oxidation and hydrolysis reaction occur on one side of the oxidant electrode, which not only reduces the fuel utilization rate, but also can cause the polarization on one side of the oxidant electrode to be greatly increased, thereby causing the cell voltage to be reduced and seriously affecting the performance of the DBFC. While

The direct oxidation reaction of (a) is the most important factor affecting the performance of the DBFC, which is inseparable from the anode catalyst. The current research shows that: noble metals, e.g. Pt, Pd, etc., for

Has high catalytic activity. However, the high price of noble metals severely limits the commercial development of DBFCs. In order to reduce the production cost, the same pair

The oxidation of non-noble metals Ni with catalytic capabilities has been increasingly studied. However, in the prior art, when Ni is used as the anode catalyst of DBFC, the catalytic activity is far lower than that of the noble metal catalyst, and

the hydrolysis reaction of (2) is more severe. In addition, metal Ni generates hydroxide on the surface under the alkaline condition for a long time, so that catalytic activity of catalytic sites is lost, charge mass transfer resistance of electrode reaction is increased, reaction rate is reduced, fuel utilization rate is low, and catalyst attenuation is caused. Although the non-noble metal Ni is inferior in catalytic performance to the noble metal, it has an absolute advantage in price. Therefore, the search for a non-noble metal Ni-based anode catalyst with excellent performance is an important problem to be solved urgently on the research and development path of DBFC.

Disclosure of Invention

In order to overcome a series of disadvantages mentioned above, the present invention relates to an enhancement

A porous microsphere nickel-based catalyst which is directly oxidized and has good stability. Utensil for cleaning buttockThe preparation method of the preparation is as follows:

(1) under normal temperature and pressure, 0.2mol dm is prepared^-3Nickel chloride (NiCl)₂·6H₂O) and 4.5mol dm^-3Ammonium chloride (NH)₄Cl);

(2) assembling a three-electrode system: placing a smooth Ni sheet of 1cm multiplied by 2cm as a working electrode in the solution, taking a carbon strip as a counter electrode and a saturated calomel electrode as a reference electrode;

(3) the nickel-based catalyst is prepared by adopting a pulse voltage deposition method under 298.15K, wherein the high voltage is-0.3V-0V, the low voltage is-1.7V, the duty ratio is 50%, the frequency is 25mHz, and the deposition time is 750 s.

The nickel-based catalyst prepared by adopting the pulse voltage deposition method is formed by stacking microspheres with small holes on the surface, so that the specific surface area of the catalyst is obviously increased, the catalytic active sites are greatly increased, and the number of the catalytic active sites is obviously reduced

The charge mass transfer resistance of the direct oxidation reaction is improved, thereby effectively promoting the catalysis

Activity of direct oxidation and fuel utilization; meanwhile, the stability of the catalyst is enhanced, and when the catalyst is used as a DBFC (double-walled carbon fiber) anode catalyst, the open-circuit potential, the limiting current density, the maximum power density and the like of a cell are greatly improved.

Drawings

FIG. 1 shows different nickel-based catalysts

Cyclic voltammograms of direct oxidation;

FIG. 2 XRD patterns of different nickel-based catalysts;

FIG. 3 SEM of Ni plate catalyst;

FIG. 4 PVE_0.20SEM image of catalyst;

FIG. 5 PVE_0.15SEM image of catalyst;

FIG. 6 PVE_0.10SEM image of catalyst;

FIG. 7 Ni plate catalyst action

Electrochemical impedance spectroscopy of direct oxidation;

FIG. 8 shows different nickel-based catalysts

Electrochemical impedance spectroscopy of direct oxidation;

FIG. 9 is a graph of chronoamperometry under the action of Ni pellets and different nickel-based catalysts;

FIG. 10 Ni plate and PVE_0.15Under the action of catalyst

Discharge curve of direct oxidation;

FIG. 11 is a schematic diagram of a DBFC device;

FIG. 12 polarization curves of DBFC with different catalysts;

FIG. 13 Power density curves for DBFC with different catalysts.

Detailed Description

The invention is further illustrated with reference to the following figures and examples: