阅读说明：本技术 基于微流体电化学池的氧还原催化剂测试平台及测试方法 (Oxygen reduction catalyst test platform and test method based on microfluid electrochemical cell ) 是由 叶丁丁 张浩然 朱恂 廖强 陈蓉 李俊 付乾 张亮 于 2019-10-01 设计创作，主要内容包括：本发明公开了一种基于微流体电化学池的氧还原催化剂测试平台及测试方法；一种基于微流体电化学池的氧还原催化剂测试平台,包括微流体电化学池、数据采集器、微泵、电子电路和参比电极,其特征在于：所述微流体电化学池包括从上往下顺序设置的阴极盖板、电解液流道板和阳极底板；所述阴极盖板上设置有阴极空气呼吸孔,阴极空气呼吸孔内放置待测阴极；所述待测阴极由疏水多孔碳纸以及氧还原催化层构成；阴极空气呼吸孔的前后侧电解液进口和电解液出口；所述电解液进口和电解液出口与电解液通道板上设置的电解液流道相连通,所述电解液流道内放置金属阳极；阳极底板设置在电解液流道板的下方；本发明可广泛应用在能源、化工、环保等领域。(The invention discloses an oxygen reduction catalyst testing platform and a testing method based on a microfluid electrochemical cell; the utility model provides an oxygen reduction catalyst test platform based on microfluid electrochemical cell, includes microfluid electrochemical cell, data collection station, micropump, electronic circuit and reference electrode, its characterized in that: the microfluid electrochemical cell comprises a cathode cover plate, an electrolyte runner plate and an anode bottom plate which are sequentially arranged from top to bottom; a cathode air breathing hole is formed in the cathode cover plate, and a cathode to be detected is placed in the cathode air breathing hole; the cathode to be detected consists of hydrophobic porous carbon paper and an oxygen reduction catalyst layer; the electrolyte inlet and the electrolyte outlet are arranged at the front side and the rear side of the cathode air breathing hole; the electrolyte inlet and the electrolyte outlet are communicated with an electrolyte flow channel arranged on the electrolyte channel plate, and a metal anode is placed in the electrolyte flow channel; the anode bottom plate is arranged below the electrolyte runner plate; the invention can be widely applied to the fields of energy, chemical industry, environmental protection and the like.)

1. The utility model provides an oxygen reduction catalyst test platform based on microfluid electrochemical cell, includes microfluid electrochemical cell (11), data collection station (12), micropump (13), electronic circuit (14) and reference electrode (15), its characterized in that:

the microfluid electrochemical cell (11) comprises a cathode cover plate (1), an electrolyte runner plate (6) and an anode bottom plate (9) which are sequentially arranged from top to bottom; a cathode air breathing hole (2) is formed in the cathode cover plate (1), and a cathode (5) to be detected is placed in the cathode air breathing hole (2); the cathode (5) to be detected is composed of hydrophobic porous carbon paper and an oxygen reduction catalyst layer; electrolyte inlets (3) and electrolyte outlets (4) at the front side and the rear side of the cathode air breathing hole (2); the electrolyte inlet (3) and the electrolyte outlet (4) are communicated with an electrolyte runner (7) arranged on an electrolyte channel plate (6), and a metal anode (8) is arranged in the electrolyte runner (7); the anode bottom plate (9) is arranged below the electrolyte runner plate (6);

the cathode (5) to be tested and the metal anode (8) are respectively connected with an electronic circuit (14) to form a discharge loop;

the data collector (12) is respectively connected with a cathode (5) to be tested of the battery and a reference electrode (15), so that a polarization curve of cathode potential change during discharge of the microfluidic electrochemical cell is collected;

the micro pump (13) is used for pumping electrolyte into the micro-fluid electrochemical cell (11) at a certain flow rate.

2. An oxygen reduction catalyst testing method based on a microfluid electrochemical cell is characterized by comprising the following steps:

firstly, the method comprises the following steps: spraying the prepared oxygen reduction catalyst slurry to be tested on the surface of hydrophobic carbon paper with a leveling layer, and drying at normal temperature to be used as a cathode to be tested;

II, secondly: assembling a microfluidic electrochemical cell: the microfluid electrochemical cell (11) comprises a cathode cover plate (1), an electrolyte runner plate (6) and an anode bottom plate (9) which are sequentially arranged from top to bottom; a cathode air breathing hole (2) is formed in the cathode cover plate (1), and a cathode (5) to be detected is placed in the cathode air breathing hole (2); electrolyte inlets (3) and electrolyte outlets (4) at the front side and the rear side of the cathode air breathing hole (2); the electrolyte inlet (3) and the electrolyte outlet (4) are communicated with an electrolyte runner (7) arranged on an electrolyte channel plate (6), and a metal anode (8) is arranged in the electrolyte runner (7); the anode bottom plate (9) is arranged below the electrolyte runner plate (6);

thirdly, the method comprises the following steps: respectively connecting the cathode (5) to be tested and the metal anode (8) with an electronic circuit (14) to form a discharge loop;

fourthly, the method comprises the following steps: the data acquisition unit (12) is respectively connected with the cathode (5) to be detected and the reference electrode (15), so that the data acquisition unit (12) is utilized to collect the polarization curve of the cathode potential change during the discharge of the microfluid electrochemical cell;

fifthly: introducing electrolyte into an electrolyte inlet (3) of the electrochemical cell at a certain flow rate by using a micro pump (13) to start the cell;

sixthly, the method comprises the following steps: the electronic circuit (14) is adjusted to change the load resistance from a set resistance value to 0 and a data collector (12) is used to collect a polarization curve of the cathode potential change as the microfluidic electrochemical cell discharges.

Technical Field

The invention relates to the field of fuel cells, in particular to an oxygen reduction catalyst testing platform and a testing method based on a microfluid electrochemical cell.

Background

Energy problems have become a key issue affecting the development of human society. The traditional fossil fuel is non-renewable energy, and has the problems of environmental pollution, low conversion efficiency and the like. Fuel cells have become a promising energy source power plant as a device that can directly convert chemical energy into electrical energy. The fuel cell generally has higher energy conversion efficiency, the fuel is generally renewable substances such as hydrogen, methanol and the like, and the reaction product is mainly water, so that the fuel cell has the characteristics of quiet operation and environmental friendliness. At present, the fuel cell technology is rapidly developed, wherein a Proton Exchange Membrane Fuel Cell (PEMFC) has the most commercial prospect, and the basic working principle is as follows: the hydrogen gas is oxidized at the anode to generate hydrogen ions and electrons, the hydrogen ions are transferred to the cathode through the proton exchange membrane, the electrons are conducted to the cathode through an external circuit, and the oxygen gas is combined with the electrons and the hydrogen ions at the cathode to generate water. The proton exchange membrane as a solid electrolyte only allows protons to pass through but not hydrogen molecules, and has extremely low water leakage rate. The oxidant is introduced into the cathode side to perform reduction reaction with electrons and hydrogen ions.

The best catalyst for the cathode catalyst in PEMFCs is currently the Pt catalyst. Pt is a precious metal, expensive and low in reserves, and the currently known Pt reserves are not sufficient even if only PEMFCs are applied to automobile power. Therefore, the development of a cathode oxygen reduction catalyst with low price and good catalytic performance becomes a popular direction for the research of the current fuel cell.

For the performance evaluation of the cathode catalyst, the performance of the assembled fuel cell, namely the acquisition of a cathode polarization curve, is most intuitive and accurate. Conventional testing methods require the assembly of the actual cell, including catalyst spray, hot pressing of the membrane electrode assembly, cell assembly, development of tests, and other relatively long procedures and cycles. And the cathode is directly contacted with a proton exchange membrane (such as a Nafion membrane), water generated by an oxygen reduction reaction is transmitted into the porous cathode, the saturation of a liquid phase in the porous cathode is increased, the oxygen transmission resistance is increased, larger mass transfer loss is caused, and the cathode performance at high current density is not favorably obtained. At the same time, it is desirable to characterize the performance of a battery, except for the cathode, which is not negligible for the anode. The transport limitation of anode fuel to the catalyst may also affect cell performance, and characterization of cathode performance with this result may be inaccurate.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides an oxygen reduction catalyst test platform and a test method based on a microfluid electrochemical cell.

The technical scheme of the invention is as follows: the utility model provides an oxygen reduction catalyst test platform based on microfluid electrochemical cell, includes microfluid electrochemical cell, data collection station, micropump, electronic circuit and reference electrode, its characterized in that:

the microfluid electrochemical cell comprises a cathode cover plate, an electrolyte runner plate and an anode bottom plate which are sequentially arranged from top to bottom; a cathode air breathing hole is formed in the cathode cover plate, and a cathode to be detected is placed in the cathode air breathing hole; the cathode to be detected consists of hydrophobic porous carbon paper and an oxygen reduction catalyst layer; the electrolyte inlet and the electrolyte outlet are arranged at the front side and the rear side of the cathode air breathing hole; the electrolyte inlet and the electrolyte outlet are communicated with an electrolyte flow channel arranged on the electrolyte channel plate, and a metal anode is placed in the electrolyte flow channel; the anode bottom plate is arranged below the electrolyte runner plate.

The cathode to be tested and the metal anode are respectively connected with an electronic circuit to form a discharge loop.

The data collector is respectively connected with a to-be-detected cathode and a reference electrode of the battery, so as to collect a polarization curve of cathode potential change when the microfluidic electrochemical cell discharges; the reference electrode is disposed at the end of the electrolyte flow channel.

The micro pump is used for pumping electrolyte into the micro-fluid electrochemical cell at a certain flow rate.

An oxygen reduction catalyst testing method based on a microfluid electrochemical cell is characterized by comprising the following steps:

firstly, the method comprises the following steps: and spraying the prepared oxygen reduction catalyst slurry to be tested on the surface of hydrophobic carbon paper with a leveling layer, and drying at normal temperature to be used as a cathode to be tested.

II, secondly: assembling a microfluidic electrochemical cell: the microfluid electrochemical cell comprises a cathode cover plate, an electrolyte runner plate and an anode bottom plate which are sequentially arranged from top to bottom; a cathode air breathing hole is formed in the cathode cover plate, and a cathode to be detected is placed in the cathode air breathing hole; the electrolyte inlet and the electrolyte outlet are arranged at the front side and the rear side of the cathode air breathing hole; the electrolyte inlet and the electrolyte outlet are communicated with an electrolyte flow channel arranged on the electrolyte channel plate, and a metal anode is placed in the electrolyte flow channel; the anode bottom plate is arranged below the electrolyte runner plate.

Thirdly, the method comprises the following steps: and respectively connecting the cathode to be tested and the metal anode with an electronic circuit to form a discharge loop.

Fourthly, the method comprises the following steps: respectively connecting a data collector with a cathode to be detected and a reference electrode so as to collect a polarization curve of cathode potential change when the microfluid electrochemical cell discharges; the reference electrode is disposed at the end of the electrolyte flow channel.

Fifthly: the electrolyte is pumped into the electrolyte inlet of the electrochemical cell by a micro pump at a certain flow rate to start the cell.

Sixthly, the method comprises the following steps: the electronic circuit is adjusted to change the load resistance from a set resistance value to 0 and a polarization curve of the cathode potential change as the microfluidic electrochemical cell discharges is collected by the data collector.

The oxygen reduction catalyst testing platform and the oxygen reduction catalyst testing method based on the microfluid electrochemical cell have the beneficial effects that:

1) the invention is based on the microfluid electrochemical cell, has small size, small electrode area and low manufacturing cost, adopts an electronic circuit to change an external resistance mode to carry out cathode polarization curve test, and has convenient and efficient test.

2) The electrochemical cell is convenient and fast to assemble, and the air self-breathing cathode does not need complex hot pressing and assembling processes, so that the test flow is shortened, and the test time is shortened. The electrochemical cell does not need a proton exchange membrane, so that the structure is simplified and the cost is reduced.

3) The anode adopts a metal electrode to generate an oxidation reaction in situ, so that the problem that the traditional fuel cell cathode catalyst is limited by anode reactant transmission during characterization is solved.

4) The metal anode reaction product does not poison the cathode catalyst, and the cathode catalyst can be repeatedly used under different working conditions.

The invention can be widely applied to the fields of energy, chemical industry, environmental protection and the like.

Drawings

FIG. 1 is a schematic diagram of the connection of an oxygen reduction catalyst test platform based on a microfluidic electrochemical cell.

Fig. 2 is a three-dimensional cross-sectional view of a microfluidic electrochemical cell 11. .

Fig. 3 is a front view of the microfluidic electrochemical cell 11.

Fig. 4 is a top view of the microfluidic electrochemical cell 11.

Detailed Description

Referring to fig. 1 to 4, an oxygen reduction catalyst testing platform based on a microfluidic electrochemical cell includes a microfluidic electrochemical cell 11, a data collector 12, a micro pump 13, an electronic circuit 14 and a reference electrode 15.

The microfluid electrochemical cell 11 comprises a cathode cover plate 1, an electrolyte runner plate 6 and an anode bottom plate 9 which are arranged from top to bottom in sequence; a cathode air breathing hole 2 is formed in the cathode cover plate 1, and a cathode 5 to be detected is placed in the cathode air breathing hole 2; the cathode 5 to be detected is composed of hydrophobic porous carbon paper and an oxygen reduction catalyst layer; the electrolyte inlet 3 and the electrolyte outlet 4 are arranged at the front side and the rear side of the cathode air breathing hole 2; the electrolyte inlet 3 and the electrolyte outlet 4 are communicated with an electrolyte runner 7 arranged on an electrolyte channel plate 6, and a metal anode 8 is placed in the electrolyte runner 7; the anode floor 9 is disposed below the electrolyte flow field plate 6.

The cathode 5 to be measured and the metal anode 8 are respectively connected with an electronic circuit 14 to form a discharge loop.

The data collector 12 is respectively connected with the cathode 5 to be measured of the battery and the reference electrode 15, so as to collect the polarization curve of the cathode potential change when the microfluid electrochemical cell discharges; the reference electrode 15 is provided at the end of the electrolyte flow channel 7. The reference electrode 15 may be inserted into the electrolyte flow channel 7 through the electrolyte outlet or the electrolyte inlet.

The micro pump 13 is used to pump electrolyte into the microfluidic electrochemical cell 11 at a certain flow rate.

In a particular embodiment, the metal anode 8 is made of a zinc sheet; the cathode 5 to be measured is formed by uniformly spraying Pt/C catalyst or non-noble metal oxygen reduction catalyst slurry on the surface of hydrophobic carbon paper with a leveling layer by a spraying method and drying at normal temperature.

A method for testing an oxygen reduction catalyst based on a microfluidic electrochemical cell, the method comprising the steps of:

firstly, the method comprises the following steps: and spraying the prepared oxygen reduction catalyst slurry to be tested on the surface of hydrophobic carbon paper with a leveling layer, and drying at normal temperature to be used as a cathode to be tested.

II, secondly: assembling a microfluidic electrochemical cell: the microfluid electrochemical cell 11 comprises a cathode cover plate 1, an electrolyte runner plate 6 and an anode bottom plate 9 which are arranged from top to bottom in sequence; a cathode air breathing hole 2 is formed in the cathode cover plate 1, and a cathode 5 to be detected is placed in the cathode air breathing hole 2; the electrolyte inlet 3 and the electrolyte outlet 4 are arranged at the front side and the rear side of the cathode air breathing hole 2; the electrolyte inlet 3 and the electrolyte outlet 4 are communicated with an electrolyte runner 7 arranged on an electrolyte channel plate 6, and a metal anode 8 is placed in the electrolyte runner 7; the anode floor 9 is disposed below the electrolyte flow field plate 6.

Thirdly, the method comprises the following steps: and respectively connecting the cathode 5 to be tested and the metal anode 8 with an electronic circuit 14 to form a discharge loop.

Fourthly, the method comprises the following steps: the data acquisition unit 12 is respectively connected with the cathode 5 to be measured and the reference electrode 15, so as to collect the polarization curve of the cathode potential change when the microfluid electrochemical cell discharges; the reference electrode 15 is provided at the end of the electrolyte flow channel 7, and the reference electrode 15 can be inserted into the electrolyte flow channel 7 through the electrolyte outlet or the electrolyte inlet.

Fifthly: introducing electrolyte into an electrolyte inlet 3 of the electrochemical cell at a certain flow rate by using a micro pump 13 to start the cell; the electrolyte flows in the electrolyte flow channel 7 and flows out from the electrolyte outlet 4; the electrolyte can adopt potassium hydroxide solution.

Sixthly, the method comprises the following steps: electronic circuit 14 is adjusted to slowly change the load resistance from a set resistance value to 0 and data collector 12 is used to collect a polarization curve of the cathode potential change as the microfluidic electrochemical cell discharges. Electronic circuit 14 may be specifically adjusted to drop the load resistance by 10 ohms per minute from a set resistance value until a short circuit, and data collector 12 may be used to collect polarization curves of cathode potential changes and cell current as the microfluidic electrochemical cell discharges. The catalytic performance of the oxygen reduction catalyst can be qualitatively obtained by a polarization curve.

The working principle of the invention is as follows: the anode zinc sheet is oxidized to lose electrons, and the electrons reach the cathode through the load by an external circuit. Oxygen in the air is transmitted to the catalyst layer through the cathode porous electrode, and oxygen reduction reaction is carried out under the action of the oxygen reduction catalyst.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.