KR20130123263A - Ni catalyst for hydrogen evolution reaction and method for preparing the same - Google Patents

Abstract

Provided is a nickel catalyst containing nickel dendrite for hydrogen evolution reaction and a method for manufacturing the same. Provided is a method for manufacturing a nickel catalyst for hydrogen evolution reaction, characterized by forming nickel dendrite through electroplating. The nickel dendrite has high hydrogen evolution reaction activity and durability to hydrogen evolution reaction, namely stability.

Description

TECHNICAL FIELD The present invention relates to a nickel catalyst for hydrogen generation reaction and a method for preparing the same,

This specification describes a nickel catalyst for hydrogen generation reaction and a method for producing the same. More particularly, the present invention relates to a nickel catalyst for hydrogen generation reaction, which can be used particularly useful for electrolysis of water, and a production method thereof.

Hydrogen production through electrolysis of water is an ideal hydrogen generation method in comparison with hydrocarbon reforming, biomass pyrolysis, and coarse gasification since there is no harmful green house gas emission and is environment friendly (Non-Patent Documents 1 and 2).

However, there are still many limitations in commercializing electrolysis. First, electrolysis is a relatively expensive process to date than the hydrocarbon reforming that is widely used in hydrogen production. In addition, the hydrogen evolution reaction (HER) can start at a large potential, and the electrolysis system itself has a problem of stability during long-term operation and a shut-down problem.

In order to overcome these problems, studies have been made to use various metals as hydrogen generating reaction catalysts (Non-Patent Documents 3 to 11).

Techniques have been introduced to explain the catalytic performance of various catalyst candidates, for example, by using a volcano plot obtained from the current density of the hydrogen generation reaction as a function of the calculated hydrogen adsorption energy (Non-Patent Documents 4 to 6) .

If the binding force between adsorbed hydrogen and the metal surface is too weak, it is difficult to activate hydrogen on the metal surface. On the other hand, strong hydrogen bonding at the metal surface limits possible reaction sites. Studies have shown that nickel among the noble metal metals has the highest catalytic activity for the hydrogen evolution reaction due to the proper adsorption energy of hydrogen on the surface (Non-Patent Documents 7 and 8).

 Catalysis for Sustainable Energy Production, ed. P. Barbaro and C. Bianchinin, Wiley-VCH, Weinheim, 2009.  Handbook of Fuel Cells: Fundamentals, Technology and Applications, ed. W. Vielstich, A. Lamm and H. Gasteiger, Wiely, Chichester, 2003.  M. Miles, J. Electroanal. Chem., 1975, 60, 89.  S. Trasatti, J. Electroanal. Chem., 1972,39, 163.  J. K. Norskov, T. Bligaard, A. Logadottir, J. R. Kitchin, J. G. Chen, S. Pandelov and U. Stimming, J. Electrochem, Soc., 2005, 152, J23.  J. Greeley, J. K. Norskov, L. A. Kibler, A. M. El-Aziz and D. M. Colb, ChemPhys Chem., 2006, 7, 1032.  J. Greeley and M. Mavrikakis, Nat. Mater., 2004, 3, 810.  J. Greeley, T. F. Jaramillo, J. Bonde, I. Chrokendorff and Norskov, Nat.Mater., 2006, 5, 909.  R. Gomez, A. Fernandez-Vega, J. M. Feliu and A. Aldaz, J. Phys., Chem., 1993, 97, 4769.  R. Gomez, J. M. Feliu and A. Aldaz, Electrochim, Acta, 1997, 42, 1675.  M.Mavrikakis, Nat.Mater., 2006, 5.847.

The inventors of the present invention conducted electroplating to find various morphologies of nickel catalysts having the highest hydrogen generation reaction activity in nickel catalyst and durability (stability) against hydrogen generation reaction. Nickel catalyst was prepared. In this process, it was confirmed that the specific nickel catalyst shape has the highest hydrogen generation reaction activity and the stability against the hydrogen generation reaction. Thus, the present invention has been accomplished.

In embodiments of the present invention, there is provided a nickel catalyst for a hydrogen generating reaction, comprising a nickel dendrite.

In an exemplary embodiment of the present invention, the nickel dendrite includes a (111) crystal face.

In an exemplary embodiment of the invention, the nickel dendrites are used to increase the catalytic activity of the hydrogen evolution reaction.

In an exemplary embodiment of the invention, the nickel dendrites are used to increase the stability of the catalytic activity of the hydrogen evolution reaction.

In an exemplary embodiment of the present invention, the nickel catalyst is used as an electrolysis catalyst for water.

Embodiments of the present invention also provide a method for producing a nickel catalyst for hydrogen generation reaction, characterized in that nickel dendrites are formed through electroplating.

In an exemplary embodiment of the present invention, electroplating is performed so that the number of (111) crystal faces in the nickel dendrite is increased in the nickel catalyst production method.

Embodiments of the present invention provide a method for increasing the catalytic activity of a hydrogen generating reaction using nickel tentrite as a catalyst.

Embodiments of the present invention provide a method for increasing the stability of the catalytic activity of a hydrogen generating reaction using nickel dendrite as a catalyst.

According to embodiments of the present invention, nickel dendrites have high hydrogen generating reaction activity among various forms of nickel catalysts and are excellent in durability against hydrogen generation reaction, that is, stability.

1 is a graph of LSV of nickel reduction on a glacier carbon electrode performed at 0.5 M NiCl ₂ electrolyte at a scan rate of 20 mVs ^-1 at 298 K in an embodiment of the present invention. 1, the x-axis represents the potential (V vs. SCE) and the y-axis represents the current density (mA / cm ² ).
Fig. 2 is a graph showing the results of a comparison between the nickel dendrite (a) (Example 1), the nickel particles (b) (Comparative Example 1), the nickel film (c) FESEM (field emission scanning electron microscopy) photograph of nickel foil (d).
Figure 3 shows the CV results for the hydrogen evolution reactions of the various nickel catalysts obtained in this and comparative examples. Fig. 3A shows a nickel dendrite, Fig. 3B shows nickel particles, Fig. 3C shows a nickel film, and Fig. 3D shows a case of a commercial nickel foil. 3A to 3D, the x-axis represents the potential (V vs. SCE) and the y-axis represents the current density (mA / cm ² ).
FIG. 4A shows the CV results for the hydrogen generation reaction of each nickel catalyst in the 50th cycle in FIG. In FIG. 4A, the x-axis represents the potential (V vs. SCE) and the y-axis represents the current density (mA / cm ² ). The internal graph of FIG. 4A shows a case where the current density is -1.6V. Figure 4b shows a tafel plot for the hydrogen evolution of the various nickel catalysts obtained in this and comparative examples. In FIG. 4B, the x-axis is the over-potential (V) and the y-axis is the logarithm of the current density. The internal graph in FIG. 4B shows the case of the exchange current density.
FIG. 5 is a graph showing the results of evaluating the stability of the catalyst of the examples of the present invention and the comparative examples for the hydrogen generation reaction during a long-term operation.
FIG. 6 is a graph showing the electrochemical surface area of the catalyst of Examples and Comparative Examples of the present invention evaluated by CV. 6, the x-axis is the potential (V vs. SCE) and the y-axis is the current (A).
7 is a high-resolution transmission cell microscope image (HRTEM) of the nickel dendrite of Example 1 of the present invention. Figs. 7A and 7F are HRTEM images of the sharp edges of the nickel dendrite of Fig. 7A, and Figs. 7E and 7F are HRTEM images of the smooth edge. The internal image in FIG. 7A represents a selected area electron diffraction (SEAD) image of the nickel dendrite. 7B to 7F, the internal image shows an FTT (Fast Fourier Transform) pattern.
8 is a high-resolution transmission electron microscope image (HRTEM) of the nickel particles of Comparative Example 1 of the present invention. The image is taken at -1.2V for 5 seconds. 8A shows nickel particles, and FIGS. 8B to 8D are HRTEM images of the smooth edges of the nickel particles of 8a. The internal image in FIG. 8A represents a selected area electron diffraction (SEAD) image of nickel particles. 8B to 8D, the internal image shows a Fast Fourier Transform (FTT) pattern.
9 shows XRD patterns of nickel dendrites before nickel electroplating and after electroplating (-0.8 V for 180 seconds) in this embodiment.
FIG. 10A shows a chronoam ferrometric (CA) graph of the hydrogen generation reaction for various nickel catalysts at 298K and 6.0M KOH electrolytes in this example and comparative examples. 10A, the x-axis is time (s) and the y-axis is current density (mA / cm ² ). Figure 10b shows average hydrogen production rates for various nickel catalysts of this and comparative examples.

Hereinafter, a nickel catalyst for hydrogen generation reaction according to embodiments of the present invention and a method for producing the same will be described in detail.

In this specification, dendrites mean dendritic crystals.

As used herein, the stability of the catalytic activity means a catalytic property which does not cause a decrease in the activity of the catalyst even when a plurality of cycles (for example, 2000 cycles) are repeated, and the degradation thereof is minimized.

In addition to the type of metal, the physical properties, size, shape, and crystallographic structure of the catalyst may also affect catalytic activity. The size and shape of the catalyst are closely related to the surface area, which affects the catalytic activity. Moreover, adjusting the orientation of the metal catalyst surface is effective in improving the catalytic properties. The crystal orientation affects the mechanical behavior of the electrochemical reaction because the activation energy for reactant adsorption on the metal surface is a function of the distance between adjacent atoms.

The inventors of the present invention conducted electroplating to find various morphologies of nickel catalysts having the highest hydrogen generation reaction activity in nickel catalyst and durability (stability) against hydrogen generation reaction. Nickel catalyst.

For reference, electroplating not only simplifies the manufacturing process but also improves the catalyst availability, and the purity of the electroplated metal is higher than that of other chemical reduction methods. In addition, the morphology, especially the orientation, of the catalyst can be easily controlled by electroplating. Although the size, shape and orientation in the initial growth stage can be influenced by the substrate, this effect is gradually reduced in the growth process, and the crystal orientation of the electroplated metal is dislocation, And may be mainly affected by electroplating conditions such as bath composition, pH, and temperature.

In the course of preparing a nickel catalyst having various morphologies through electroplating as described above, the present inventors have found that dendrites in the form of nickel catalyst have the highest hydrogen generation reaction activity and also have excellent durability against hydrogen generation reaction, that is, stability. Respectively.

Accordingly, embodiments of the present invention provide a nickel catalyst for hydrogen generation reaction comprising nickel dendrite as a nickel catalyst for hydrogen generation reaction.

In an exemplary embodiment, the nickel dendrite is grown along the (111) crystal face.

In an exemplary embodiment, the nickel catalyst is useful for electrolysis of water, particularly electrolysis of basic water.

Embodiments of the present invention also provide a method for producing a nickel catalyst for hydrogen generation reaction, characterized in that nickel dendrites are formed through electroplating.

In an exemplary embodiment, electroplating is performed to increase the number of (111) crystal faces in nickel dendrites during the manufacture of the catalyst.

The nickel dendrite according to embodiments of the present invention has high hydrogen generating reaction activity among various forms of nickel catalysts and has excellent durability against hydrogen generation reaction, that is, stability. Therefore, when the nickel dendrite is used as a catalyst, And thus it is useful for increasing the stability of the hydrogen generation reaction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the embodiments of the present invention.

Glacier  Nickel electroplating on carbon electrodes

A solution of 0.5 M nickel (II) chloride hexahydrate (NiCl ₂ .H ₂ O; Kanto Chemical Co., 28115-00) was used as the electrolyte for nickel plating. The pH of the electrolyte was adjusted to 2.5 by adding hydrochloric acid. The electrolyte was purged with argon for 10 minutes before the electroplating process. A typical three electrode cell system consisting of a glazed carbon electrode having a geometric area of 1.32 cm ² plated with a nickel catalyst as the working electrode, a platinum wire as the counter electrode and a saturated calomel electrode (SCE; Sigma Aldrich) as the reference electrode was electrochemically Used for processes. A 1.32 cm ² glacial carbon electrode was exposed to the electrolyte and the other was sealed with a Teflon holder made in the laboratory. The electroplating process was controlled by a Potentiostat (Autolab, PGSTAT 302).

After electroplating, the catalyst size distribution, density and morphology were evaluated using a field emission scanning electron microscope (FESEM; Hitachi, S-4100) to investigate the characteristics of the nickel catalyst on the gyroscopic electrode.

Nickel dendrites and nickel particles separated from the glaring carbon electrode by ultrasonic treatment were investigated using selected area electron diffraction (SEAD) and FTT (Fast Fourier Transform) patterns.

X-ray diffraction (XRD; Rigaku D / Max 2500) was used to investigate the crystal structure after the nickel film was formed by electroplating for a long time.

The loading mass of the nickel catalyst on glacier carbon was measured using inductively coupled plasma mass spectroscopy (ICPMS; PerkinElmer Sciex, ELAN 6100 DRC plus).

Cyclic voltammetry (CV) and chronoam ferrometry (CA) were performed using potentiostat with a typical three-electrode cell system.

The catalytic activity for the hydrogen evolution reaction was analyzed by CV scans at a scan rate of 50 mV s ^-1 in a potential range of -1.0 V to -1.6 V (vs. SCE) in a 6.0 M KOH solution purged with argon bubbling for 10 minutes . After analyzing the catalyst performance, the catalytic activity of the electroplated nickel catalyst and a comparative nickel foil (Sigma Aldrich, 268259) were compared in consideration of the CV current density and the starting potential. 2000 cycles of CV over a long period of operation on nickel dendrite were performed in a 6.0 M KOH solution at a scan rate of 50 mV s ^-1 . Gas production was carried out by CA at -1.6V for 60 minutes. The production rate was measured with a digital flow meter (Humonics Inc., 420).

result

To determine the optimal electroplating potential in electroplating nickel on a glacier carbon electrode, a linear sweep voltammetry analysis was first performed on an argon purged 0.5 M NiCl ₂ solution.

1 is a graph of LSV of nickel reduction on a glacier carbon electrode performed at 0.5 M NiCl ₂ electrolyte at 298 K at a scan rate of 20 mVs ^-1 in embodiments of the present invention. 1, the x-axis represents the potential (V vs. SCE) and the y-axis represents the current density (mA / cm ² ).

As shown in Fig. 1, the reduction of nickel on the substrate started at -0.7 V, and the current slowly increased as the potential shifted in the negative direction. The closer to the start potential, the more current was used for nickel reduction. This area can be named the free growth stage. On the other hand, on the negative side, the current was used for nickel reduction on the substrate and hydrogen generation on the plated nickel surface. This region can be called the hydrogen contribution growth step. In this region, nickel-plated was followed by hydrogen-contributed growth.

The activation energy for hydrogen adsorption on the nickel surface during electroplating is a function of the distance between adjacent nickel atoms. Therefore, the generated hydrogen atoms are selectively adsorbed on the nickel surface depending on the type of the facet. Adsorbed hydrogen reduces growth rate while inhibiting facet growth. Thus, hydrogen adsorption can be used to determine the nickel crystal structure.

After nickel electroplating at various electroplating potentials, nickel dendrites and particles were obtained at the potential of the free growth stage (-0.8 V for 5 seconds) and the hydrogen contribution growth stage (-1.2 V for 5 seconds), respectively.

Fig. 2 is a graph showing the results of a comparison between the nickel dendrite (a) (Example 1), the nickel particles (b) (Comparative Example 1), the nickel film (c) FESEM (field emission scanning electron microscopy) photograph of nickel foil (d).

As shown in FIG. 2A, the flower-like dendrites (Example 1) were typically 150 nm to 200 nm (FIG. 2A). On the other hand, spherical particles (Comparative Example 1) were about 300 nm in size (Fig. 2B). The shape of this nickel was affected by the electroplating potential.

Figures 2c and 2d show a nickel film (Comparative Example 2) and a commercial nickel foil (Sigma Aldrich) (Comparative Example 3). Nickel particles were grown at -1.2 V for 20 seconds and then agglomerated to form a film. The commercial nickel foil was used for comparison with the catalytic activity of nickel dendrite, nickel particles, and nickel film.

Cyclic voltammetry (CV) measurements were performed at room temperature and 6.0 M KOH electrolyte at a scan rate of 50 mVs ^-1 to evaluate the catalytic activity and stability of the various nickel catalysts obtained above.

Figure 3 shows the CV results for the hydrogen evolution reactions of the various nickel catalysts obtained in this and comparative examples. Here, the potential range is -1.0V to -16V. Fig. 3A shows a nickel dendrite, Fig. 3B shows nickel particles, Fig. 3C shows a nickel film, and Fig. 3D shows a case of a commercial nickel foil. 3A to 3D, the x-axis represents the potential (V vs. SCE) and the y-axis represents the current density (mA / cm ² ).

As can be seen in Figure 3, the current density in the first cycle was a peak at -1.6V. The overvoltages induced by the formation of hydrogen bubbles on the catalyst surface gradually reduced the current density in the following cycles. After the 20th cycle, a stable CV curve having an equilibrium state of hydrogen bubble formation / removal was obtained.

Figure 4A shows the CV results for the hydrogen evolution of each nickel catalyst in the 50th cycle in Figure 2. In FIG. 4A, the x-axis represents the potential (V vs. SCE) and the y-axis represents the current density (mA / cm ² ). The internal graph of FIG. 4A shows a case where the current density is -1.6V.

Figure 4b shows a tafel plot for the hydrogen evolution of the various nickel catalysts obtained in this and comparative examples. In FIG. 4B, the x-axis is the over-potential (V) and the y-axis is the logarithm of the current density. The internal graph in FIG. 4B shows the case of the exchange current density. The kinetic behavior of the catalysts can be evaluated through the corresponding TAPEL graph.

The measured exchange current densities and transfer coefficients are shown in Table 1. The figures show results consistent with the catalyst performance determined by the CV graphs.

Electrode type inclination
(-2.3RT / aF, Vdec- ¹ ) Transfer Factor (a) Y-axis intercept (logi ₀ ) Exchange current density
(i ₀ , ma / cm ^-2 ) Comparative Example 3
Nickel foil -0.3001 0.1971 -1.8130 0.0154 Comparative Example 2
Nickel film -0.0988 0.5987 -1.6903 0.0204 Comparative Example 1
Nickel particles -0.1196 0.4946 -1.5402 0.0288 Example 1
Nickel dendrite -0.1027 0.5760 -1.3323 0.0465

FIG. 5 is a graph showing the results of evaluating the stability of the catalyst of the examples of the present invention and the comparative examples for the hydrogen generation reaction during a long-term operation.

As shown in FIG. 5, the stability of nickel dendrite was confirmed by comparing the results after 50, 500, 1000, and 2000 cycles. Even after 2000 cycles, the current density of the hydrogen generation reaction could be maintained.

In order to investigate the effect of the catalyst shape on the catalyst performance, the electrochemical surface area (ECSAs) was evaluated by CV. The scan speed was 10mVs- ¹ and a nitrogen purged 0.5M sodium hydroxide electrolyte was used.

FIG. 6 is a graph showing the electrochemical surface area of the catalyst of Examples and Comparative Examples of the present invention evaluated by CV. 6, the x-axis is the potential (V vs. SCE) and the y-axis is the current (A). In the graph of Fig. 6, the internal graph is an enlarged image of the peak portion in the graph of Fig.

Electrochemically overlapping peaks during the over-potential region are related to the reversible process Ni + 2OH ^-1 -> a Ni (OH) ₂ + 2e ^-1 .

From the formation of the aNi (OH) ₂ monolayer, it was confirmed that the electrochemical surface area (ECSAs) of the catalyst appeared in the order of dendrite>particle>film> foil. This ECSA result is due to the fact that the catalyst performance also depends on the shape of the catalyst. That is, it can be seen from the fact that the more the specific facet of the dendrite-shaped nickel surface is, the higher the catalyst performance is.

The catalytic activity of pure metals and alloys for the hydrogen evolution reaction can be explained by the hydrogen binding energy (BE _H ). The closer the hydrogen binding energy (BE _H ) approaches the thermally neutral hydrogen breakdown (-2.28 eV), the higher the performance. Although the hydrogen binding energy (BE _H ) of nickel was comparable to other non-precious metals except copper, it was the closest to that level but still able to maintain high performance.

In the hydrogen generation reaction, the closer the hydrogen binding energy is to the thermal neutral hydrogen decomposition value, the better the catalyst performance. In the case of nickel, the hydrogen binding energy value is larger than the thermal neutral hydrogenation value. In particular, since the (111) crystal face can lower the hydrogen binding energy value, the nickel dendrite having a large (111) .

The activation energy for hydrogen adsorption, which is a function of the distance between adjacent hydrogen atoms, decreases in the order of (111)>(100)>(110)> (211). Therefore, the hydrogen binding energy (BE _H ) of each facets decreases in the order of (211)>(110)>(100)> (111).

The characteristics of crystallinity of nickel dendrites and particles can be confirmed by high resolution transmission electron microscopy (HRTEM).

7 is a high-resolution transmission cell microscope image (HRTEM) of the nickel dendrite according to the first embodiment. The image is taken at -0.8V for 20 seconds. Figs. 7A and 7F are HRTEM images of the sharp edges of the nickel dendrite of Fig. 7A, and Figs. 7E and 7F are HRTEM images of the smooth edge. The internal image in FIG. 7A represents a selected area electron diffraction (SEAD) image of the nickel dendrite. 7B to 7F, the internal image shows an FTT (Fast Fourier Transform) pattern.

Figure 7a shows the removal of nickel dendrite from a glazed carbon support by an ultrasonic processor. The selected area electron diffraction (SEAD) shows that the dendrite includes a polycrystalline structure consisting of the facets of (211), (400), (222) and (220).

The HTTEM images at each sharp edge show their crystallinity through the FTT (Fast Fourier Transform) pattern (see FIGS. 7b through 7d). The multiple (111) planes observed at the sharp edges decreased with approaching hydrogen binding energy (BE _H ) -2.28 eV. While the (110) and (100) planes were the main growth directions in the smooth edge plane (see Figs. 7e and 7f). From these facts, it can be seen that a number of sharp edges grown to have a (111) plane improved the catalytic properties of nickel dendrites.

8 is a high-resolution transmission electron microscope image (HRTEM) of the nickel particles of Comparative Example 1. The image is taken at -1.2V for 5 seconds. 8A shows nickel particles, and FIGS. 8B to 8D are HRTEM images of the smooth edges of the nickel particles of 8a.

The internal image in FIG. 8A represents a selected area electron diffraction (SEAD) image of nickel particles. 8B to 8D, the internal image shows a Fast Fourier Transform (FTT) pattern.

With respect to the general mechanism of polycrystalline growth, it has been reported that translational and rotational diffusion can be the most important transport properties of crystallization. These two diffusions can directly control the manner in which molecules attach to and grow in the growing crystal.

By decreasing the ratio of rotational and translational diffusion coefficients, the translational diffusion is accelerated and the shape of the polycrystal changes from top to bottom. At a relatively high negative potential of -1.2V, the translational diffusion becomes better than the rotational diffusion, and the nickel is electroplated in the form of particles because the nickel ions move easily. Therefore, both the center and the edge of the particle have a polycrystalline structure. This structure can also be confirmed by selected area electron diffraction (SEAD) and FTT (Fast Fourier Transform) patterns (see FIG. 8).

On the other hand, at a low negative potential of -0.8 V, the rotation of nickel ions will dominate. The order of crystal orientation was performed at the diffuse interface, and the nickel dendrite could have one facet at the edge.

9 shows XRD patterns of nickel dendrites before nickel electroplating and after electroplating (-0.8 V for 180 seconds) in this embodiment.

As shown in Fig. 9, bare glassy carbon before nickel plating showed a broad peak of about 25 degrees in relation to carbon. On the other hand, the (111) peak corresponding to 44.5 degrees after nickel electroplating was clearly shown. From this, it can be seen that nickel dendrites grow along with a large number of (111) planes.

Chronoam ferrometry (CA) was performed to produce hydrogen. The potential was constant at -1.6 V and was performed for 60 minutes. Compared with other catalysts during hydrogen production, nickel dendrite showed the highest current density of the hydrogen generation reaction. The average hydrogen production rate was measured with a digital flow meter (Humonics Inc., 420). Five measurements were taken every 10 minutes and mean values with standard deviation were obtained.

FIG. 10A shows a chronoam ferrometric (CA) graph of the hydrogen generation reaction for various nickel catalysts at 298K and 6.0M KOH electrolytes in this example and comparative examples. 10A, the x-axis is time (s) and the y-axis is current density (mA / cm ² ). Figure 10b shows average hydrogen production rates for various nickel catalysts of this and comparative examples.

As described above, the electroplating conditions were changed to electroplating a nickel catalyst having different morphologies on the glass carbon electrode. Among them, nickel dendrite was most active and showed stable hydrogen generation reaction characteristics. The relationship between electrochemical measurements and catalytic properties was investigated and it was found that large electrochemical surface areas (ECSAs) and a large number of (111) facets at sharp edges guaranteed high activity for the hydrogen evolution reaction of nickel dendrites I could.

Claims (9)

A nickel catalyst for hydrogen generation reaction, characterized by comprising nickel dendrite. The method according to claim 1,
Wherein the nickel dendrite comprises a (111) crystal plane. The method according to claim 1,
Wherein the nickel dendrite is used for increasing the catalytic activity of the hydrogen generation reaction. The method according to claim 1,
Wherein the nickel dendrite is used for increasing the stability of the catalytic activity of the hydrogen generating reaction. The method according to claim 1,
Wherein the nickel catalyst is used as an electrolysis catalyst for water. And forming nickel dendrites by electroplating, wherein the nickel dendrites are nickel catalysts for hydrogen generation reaction. The method according to claim 6,
Wherein the electroplating is performed so that the number of (111) crystal faces in the nickel dendrite is increased. A method for increasing the catalytic activity of a hydrogen generation reaction, which comprises using nickel tentrite as a catalyst. A method for increasing the stability of catalytic activity of a hydrogen generating reaction, characterized in that nickel dendrite is used as a catalyst.

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