Non-noble metal catalyst film electrode endurance test method

Abstract

The invention discloses a non-noble metal catalyst film electrode endurance test method. The method comprises the steps of respectively testing a polarization curve, ohmic resistance and cathode catalyst layer proton conduction impedance of a film electrode at the beginning; then performing constant-voltage discharge attenuation test on the film electrode; further testing the polarization curve, ohmic resistance and cathode catalyst layer proton conduction impedance of the film electrode after attenuation; then inputting dry nitrogen into the film electrode for purging; and at last testing thepolarization curve of the film electrode after nitrogen purging by using an electrochemical workstation. According to the method, as for the non-noble metal catalyst film electrode, the polarizationcurves, ohmic resistance and cathode catalyst layer proton conduction impedance of the film electrode before and after constant-voltage discharge attenuation, and the polarization curves of the film electrode before and after nitrogen purging are tested, the test condition is the same as the film electrode test condition, and test data is true and reliable. The film electrode endurance test can beperformed from three aspects: activation polarization, ohmic polarization and mass transfer polarization, and the method is of great significance to development of the non-noble metal catalyst film electrode.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to a method for testing the durability of non-precious metal catalyst membrane electrodes. Background technique [0002] Proton exchange membrane fuel cells, which directly convert chemical energy in fuels into electrical energy, have attracted much attention due to their low pollution, zero emissions, and high conversion efficiency. However, the high performance of proton exchange membrane fuel cells currently relies on the noble metal Pt catalyst in the cathode. Metal Pt has problems such as low reserves, high price, and catalyst poisoning, which restrict the large-scale application of proton exchange membrane fuel cells. Therefore, finding and using efficient non-noble metal catalysts to replace Pt catalysts is the key to the development of this proton exchange membrane fuel cell technology. [0003] Non-precious metal catalysts studied in the past can be mainly divided into...

AI Technical Summary

Problems solved by technology

In 2006, Zelenay synthesized a catalyst with a Co-N structure without the help of pyrolysis, which showed good stability while retaining the catalyst, but the catalytic performance was not high

However, its attenuation mechanism is still unclear, and there are few reports on its durability test, and there is no clear attenuation test method

A small number of studies in the past have only focused on the effect of activation polarization, that is, the reduction in the activity of the catalyst itself, on the performance of the membrane electrode.

The influence of ohmic polarization and mass transfer polarization has not been considered; transition metals will pollute the resin in the membrane electrode in an acidic environment, resulting in an increase in the ohmic impedance of the membrane electrode and the proton conduction impedance of the catalytic layer, which in turn leads to a decrease in the performance of the membrane electrode; The water flooding of the active sites in the cathode catalytic layer will increase the oxygen transport resistance of the cathode, which will also lead to a decrease in the performance of the membrane electrode

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