A simple preparation device and method of a nickel-iron bimetallic hydroxyl oxide catalyst

Abstract

The application is suitable for the technical field of catalyst preparation, and provides a simple nickel-iron bimetallic oxyhydroxide catalyst preparation device and method. The nickel-iron bimetallic oxyhydroxide catalyst is prepared by using a solution immersion etching method, and the catalyst is prepared in an open space and a normal temperature environment without special requirements such as high temperature and high pressure. Low-cost foamed nickel and ferric nitrate are used as synthesis raw materials, and a large-area NiFe catalyst can be prepared by soaking in the solution for several minutes, so that the time consumption for preparing the NiFe material is greatly reduced. Meanwhile, in a 1M KOH medium, the prepared NiFe catalyst shows excellent oxygen evolution performance through three-electrode system testing, and the method can not only reduce the time and economic cost of catalyst preparation, but also can be used for large-scale preparation of the oxygen evolution catalyst, and provides a new method for designing a high-activity, low-cost and large-scale prepared anode oxygen evolution catalyst.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalyst preparation, and particularly relates to a simple nickel-iron bimetallic oxyhydroxide catalyst preparation device and method. BACKGROUND

[0002] Due to the large use of fossil fuels, the living environment of human beings has been greatly damaged. In order to alleviate the environmental problems, it is urgent to find clean energy to replace fossil energy. Hydrogen energy plays an important role in energy storage and conversion process. Hydrogen has the highest mass energy density (120 MJ kg -1 ) and the combustion product is water, which is the most potential clean energy. On the one hand, the electrocatalytic water splitting technology can not only meet the demand of people for hydrogen energy, but also has the advantages of recyclable, zero emission and environment-friendly, because the raw material is water and the combustion product is also water. On the other hand, the use of fossil energy causes the emission of greenhouse gas CO2, which leads to serious climate change. In this regard, the co-electrolysis of CO2 and water for electrochemical reduction at normal temperature and pressure is an important utilization way of generalized hydrogen energy, and also an important way of high-value utilization of greenhouse gas CO2. For the electrocatalytic water splitting reaction and the carbon dioxide reduction reaction, the anode oxygen evolution process is a common half-reaction involving 4-step electron-proton transfer. The reaction kinetics is slow and the energy barrier is high, which leads to the need of large power consumption in electrolysis. Therefore, we need to construct a low-cost, efficient and stable anode oxygen evolution catalyst.

[0003] At present, the most advanced oxygen evolution catalyst under alkaline and neutral conditions is NiFe-based material. The source of Ni and Fe is low in price and wide in source, and the oxygen evolution performance is excellent. However, the preparation of NiFe-based catalyst often needs to use hydrothermal method, magnetron sputtering or tubular furnace high temperature annealing, which is time-consuming and complicated, and the time cost is high. In addition, the catalyst prepared by the former has insufficient adhesion, and the latter has strict requirements for precursor solution and reaction conditions. The prepared NiFe material can only be used for experimental research, and cannot meet the application requirements of industry. Secondly, the synthesis of most of the current NiFe catalysts is in a limited space, which is limited by the narrow space of equipment, and the catalyst cannot be prepared on a large scale. SUMMARY

[0004] The purpose of the embodiment of the application is to provide a simple nickel-iron bimetallic oxyhydroxide catalyst preparation device and method, which aims to solve the problems in the above background technology.

[0005] The embodiment of the application is implemented in the following manner: a simple nickel-iron bimetallic hydroxyl oxide catalyst preparation device comprises a tank body, the bottom of the tank body is provided with a plurality of liquid inlet pipes, the upper part of the side wall of the tank body is provided with a liquid outlet pipe, the water inlet of the liquid inlet pipe is connected with the water outlet of the liquid outlet pipe through a hose, the hose is connected with an external peristaltic pump, a plurality of clamping groove assemblies for fixing foam nickel electrode sheets are equidistantly distributed in the tank body, each group of the clamping groove assemblies comprises four clamping grooves, and the four clamping grooves in the same clamping groove assembly are symmetrically installed on the opposite two side walls of the tank body, and the gap of the clamping groove is 1.2 mm.

[0006] Further technical solutions, the material of the tank body is polytetrafluoroethylene, and the size of the tank body is 30*30*33 cm 3 .

[0007] Further technical solutions, the tank body is equidistantly provided with three groups of clamping groove assemblies, the liquid inlet pipes and the liquid outlet pipe are equidistantly distributed between the three groups of clamping groove assemblies, and the liquid inlet pipe extends to the inside of the tank body.

[0008] Another purpose of the embodiment of the application is a simple nickel-iron bimetallic hydroxyl oxide catalyst preparation method based on the simple nickel-iron bimetallic hydroxyl oxide catalyst preparation device, which comprises the following steps:

[0009] Step 1, foam nickel with a thickness of 1 mm and a size of 30*30 cm 2 is sequentially cleaned with deionized water and isopropyl alcohol for 30 s, then cleaned with 0.5M H2SO4 for 2 min, and finally cleaned with deionized water for 1 min, and after cleaning, the foam nickel is fixed in the tank body through the clamping groove assembly;

[0010] Step 2, 0.5M Fe(NO)3 and 0.5M NaCl are added to a glassware, mixed and stirred uniformly, the glassware is connected with the liquid inlet pipe through the hose, the liquid in the glassware is introduced into the tank body through the liquid inlet pipe by the peristaltic pump, the liquid inlet flow rate of the solution is 30 mL / min, when the liquid surface of the solution reaches the liquid outlet pipe, the excess liquid flows back into the glassware through the liquid outlet pipe and the hose, and the circulation flow is 1-10 min;

[0011] Step 3, the foam nickel is taken out, and then cleaned with deionized water again to obtain a NiFe catalyst.

[0012] The embodiment of the present application provides a simple nickel-iron bimetallic hydroxyl oxide catalyst preparation device and method, which utilizes a solution etching method to prepare the nickel-iron bimetallic hydroxyl oxide catalyst, and the catalyst is prepared in an open space and a normal temperature environment, without special requirements such as high temperature and high pressure, and low-cost foamed nickel and ferric nitrate are used as synthesis raw materials, so that the NiFe catalyst with a large area can be prepared by soaking in the solution for several minutes, and the time consumption for preparing the NiFe material is greatly reduced. Meanwhile, in a 1MKOH medium, the prepared NiFe catalyst shows excellent oxygen evolution performance through a three-electrode system test, the method can not only reduce the time and economic cost of catalyst preparation, but also can scale the preparation of the oxygen evolution catalyst, and provides a new method for designing a high-activity, low-cost and scaled anode oxygen evolution catalyst. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 A structure schematic diagram of a simple nickel-iron bimetallic hydroxyl oxide catalyst preparation device provided by the embodiment of the present application is shown in the figure.

[0014] Figure 2 A perspective view of a simple nickel-iron bimetallic hydroxyl oxide catalyst preparation device provided by the embodiment of the present application is shown in the figure.

[0015] Figure 3 SEM images of the NiFe material under different soaking times are shown in the figures.

[0016] Figure 4 Cyclic voltammetry scanning curve graphs under different soaking times are shown in the figures.

[0017] Figure 5 Linear voltammetry scanning curve graphs under different soaking times are shown in the figures.

[0018] Figure 6 A polarization curve graph tested at a room temperature and a normal pressure environment is shown in the figure.

[0019] In the drawings, the tank body 1, the liquid inlet pipe 2, the liquid outlet pipe 3 and the clamping groove 4. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0021] The specific implementation of the present application is described in detail below with reference to specific embodiments.

[0022] As Figure 1 and 2As shown in the figure, it is a simple nickel-iron bimetallic hydroxyl oxide catalyst preparation device provided by an embodiment of the application, comprising a tank body 1, a plurality of liquid inlet pipes 2 are arranged at the bottom of the tank body 1, a liquid outlet pipe 3 is arranged at the upper part of the side wall of the tank body 1, the water inlet of the liquid inlet pipe 2 and the water outlet of the liquid outlet pipe 3 are connected through a hose, and the hose is connected with an external peristaltic pump, so as to realize circulating flow when the tank body is full of liquid, a plurality of clamping groove assemblies for fixing the foam nickel electrode sheet are equidistantly distributed in the tank body 1, each group of the clamping groove assemblies comprises four clamping grooves 4, and the four clamping grooves 4 in the same group of the clamping groove assemblies are symmetrically installed on the opposite two side walls of the tank body 1, and the gap of the clamping groove 4 is 1.2 mm, which is slightly wider than the thickness (1 mm) of the foam nickel.

[0023] As a preferred embodiment of the application, the material of the tank body 1 is polytetrafluoroethylene, and the specification of the tank body 1 is 30*30*33 cm 3 , so as to adapt to the size of the foam nickel electrode sheet.

[0024] As shown in the figures Figure 1 and 2 , as a preferred embodiment of the application, three groups of clamping groove assemblies are equidistantly distributed in the tank body 1, the liquid inlet pipe 2 and the liquid outlet pipe 3 are equidistantly distributed between the three groups of clamping groove assemblies, and the liquid inlet pipe 2 extends to the inside of the tank body 1, so that the flow field in each part of the tank body 1 is relatively uniform.

[0025] An embodiment of the application provides a simple nickel-iron bimetallic hydroxyl oxide catalyst preparation method, which is based on the above-mentioned simple nickel-iron bimetallic hydroxyl oxide catalyst preparation device and comprises the following steps:

[0026] Step 1, foam nickel (1 mm thick) with a specification of 30*30 cm 2 is sequentially cleaned with deionized water and isopropyl alcohol for 30 s, then cleaned with 0.5M H2SO4 for 2 min, and finally cleaned with deionized water for 1 min, and after the cleaning is completed, the foam nickel is fixed in the tank body 1 through the clamping groove assembly;

[0027] Step 2, 0.5M Fe(NO)3 and 0.5M NaCl are added to a glassware, mixed and stirred uniformly, the glassware is connected with the liquid inlet pipe 2 through a hose, and the liquid in the glassware is introduced into the tank body 1 through the liquid inlet pipe 2 by using a peristaltic pump, the solution inlet flow rate is 30 mL / min, when the liquid surface of the solution reaches the liquid outlet pipe 3, the excess liquid flows back to the glassware through the liquid outlet pipe 3 and the hose, and the circulating flow is 1-10 min;

[0028] Step 3, the foam nickel is taken out, and then cleaned with deionized water again, so as to obtain a NiFe catalyst.

[0029] In the embodiments of the present application, (1) characterization of the NiFe catalyst:

[0030] The surface morphology of the NiFe catalyst was analyzed by SEM. Figure 3 The SEM images of the NiFe material with different soaking times are shown: the left side shows the smooth foam nickel skeleton without etching treatment, while the sample surface is obviously etched after etching treatment, and the right side shows that the sample surface with a soaking time of 4 min is more obviously etched than the sample with a soaking time of 1.5 min; it is reflected that with the increase of the soaking time, the NiFe catalyst is more loaded on the surface of the foam nickel, and there are more reaction active sites.

[0031] (2) Electrochemical test:

[0032] The three-electrode system was used for catalyst performance screening, and the electrochemical workstation was used to determine the solution impedance, cyclic voltammetry curve and linear voltammetry curve. In the three-electrode system, the working electrode was the foam nickel for loading the NiFe catalyst, and was cut into 1×1 cm 2 , the counter electrode was a platinum mesh electrode, the reference electrode was Hg / HgO, and the electrolyte was 1M KOH. The catalyst performance is affected by factors such as soaking time, solution composition and solution concentration. By fixing the composition and concentration of the soaking solution, i.e. a mixed solution of 0.5M Fe(NO)3 and 0.5M NaCl, the performance difference of the catalyst under different soaking times was studied, and the optimal soaking time was selected. The NiFe catalysts obtained under the soaking times of 1 min, 1.5 min, 2 min, 4 min and 10 min were respectively subjected to electrochemical test, and according to the experimental results, the performance difference of the catalysts under the conditions of 1.5 min and 4 min was mainly compared.

[0033] Firstly, the catalyst was activated by cyclic voltammetry scanning curve (CV) in the range of 1.0-1.5V vs RHE, and activated for 100 cycles. Figure 4 The CV curves of different soaking times under the same activation cycles are shown, and it can be seen from the figure that the performance of the catalyst obtained by soaking for 4 min is better than that of soaking for only 1.5 min. Figure 5 The linear voltammetry scanning curve (LSV) curves under different soaking times are shown, and the scanning speed is 10mV / s. It is observed from the LSV curve that the LSV curve of the catalyst with a soaking time of 4 min only needs 560mV overpotential to reach 1000mA cm -2 current density, and the catalyst with a soaking time of 1.5 min needs 600mV overpotential to reach 1000mA cm -2 current density.

[0034] (3) Membrane electrode application:

[0035] Based on the above statements, the practical application of the NiFe catalyst was evaluated in a self-made MEA device using Membrane-electrode-assembly (MEA) membrane electrode assembly and single cell test. In the device, the MEA was prepared by using the prepared NiFe material as the anode oxygen evolution catalyst, Fumasep FAA-PK-130 anion exchange membrane and nano-Ag cathode carbon dioxide reduction catalyst. Figure 6 The polarization curve tested at room temperature and normal pressure environment is shown, and the scanning speed is 1 mV / s. The NiFe catalyst shows excellent electrocatalytic CO2 reduction performance at a current of 2 A (i.e. 0.89 A / cm 2 The current density) and a cell voltage of 3.15 V.

[0036] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A simple preparation method of a nickel-iron bimetallic oxyhydroxide catalyst, based on a nickel-iron bimetallic oxyhydroxide catalyst preparation device, characterized by, The device comprises a tank, the bottom of the tank is provided with several liquid inlet pipes, the upper part of the side wall of the tank is provided with a liquid outlet pipe, the water inlet of the liquid inlet pipe is connected with the water outlet of the liquid outlet pipe through a hose, the hose is connected with an external peristaltic pump, several clamping groove assemblies for fixing the foam nickel electrode sheet are equidistantly distributed in the tank, each clamping groove assembly comprises four clamping grooves, and the four clamping grooves in the same clamping groove assembly are symmetrically installed on the opposite two side walls of the tank, and the gap of the clamping groove is 1.2 mm. The method comprises the following steps: Step 1, the foam nickel with thickness of 1 mm, size of 30 x 30 cm 2 is sequentially cleaned with deionized water and isopropanol for 30 s, then cleaned with 0.5 M H2SO4 for 2 min, and finally cleaned with deionized water for 1 min, and after cleaning, the foam nickel is fixed in the groove body through the clamping groove assembly; Step 2, 0.5 M Fe(NO)3 and 0.5 M NaCl are added into a glass container, mixed and stirred uniformly, the glass container is connected with the liquid inlet pipe through a hose, and the liquid in the glass container is introduced into the tank through the liquid inlet pipe by using a peristaltic pump, the solution inlet flow rate is 30 mL / min, when the liquid surface of the solution reaches the liquid outlet pipe, the excess liquid flows back into the glass container through the liquid outlet pipe and the hose, and the circulation flow is 1-10 min; Step 3, the foam nickel is taken out, then washed with deionized water again, and a NiFe catalyst is obtained.

2. The simple preparation method of a nickel-iron bimetallic oxyhydroxide catalyst according to claim 1, characterized by, The material of the groove body is polytetrafluoroethylene, and the specification of the groove body is 30*30*33 cm 3 .

3. The simple preparation method of a nickel-iron bimetallic oxyhydroxide catalyst according to claim 1, characterized by, The tank is equidistantly provided with three groups of clamping groove assemblies, the liquid inlet pipes and the liquid outlet pipe are equidistantly distributed between the three groups of clamping groove assemblies, and the liquid inlet pipe extends to the inside of the tank.

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