Iridium monatomic catalyst used for direct formic acid fuel cell, and preparation method of catalyst

Abstract

The invention discloses an iridium monatomic catalyst used for a direct formic acid fuel cell, and a preparation method of the catalyst. According to the catalyst, a zinc metal compound and an imidazole type organic ligand are coordinated in an iridium metal compound methanol solution to form a metal organic framework composite material packaged with the iridium metal compound; next, the product is subjected to high-temperature calcining in inert atmosphere; the imidazole type organic ligand forms a non-metallic heteroatom nitrogen-doped porous carbon carrier; and the iridium atoms and the surrounding non-metallic heteroatom nitrogen are in interaction to be loaded on the porous carbon carrier in a mode that a single iridium atom is coordinated with four nitrogen atoms (Ir-N4). Through a simple mixed mode, the composite material of the iridium metal compound and the metal organic framework composite material is prepared; and next, through high-temperature pyrolysis, the iridium monatomic catalyst can be obtained. The method is simple and easy to implement; and the catalyst is applicable to the positive electrode reaction of the direct formic acid fuel cell, and has the characteristics of high atom utilization rate, excellent catalytic performance and high stability.

Description

technical field [0001] The invention specifically relates to an anode iridium single-atom catalyst of a direct formic acid fuel cell and a preparation method thereof, belonging to the technical field of direct formic acid fuel cells. Background technique [0002] With the development of human society, issues such as global energy consumption and climate change have aroused widespread concern, so it is imminent to find alternative clean energy. Currently, the new energy sources being developed include solar energy, wind energy, fuel cells, etc. Among them, the direct formic acid fuel cell is a device that directly converts chemical energy into electrical energy through the electrode reaction of formic acid and air to generate carbon dioxide and water. It has attracted people's attention and is considered to be one of the preferred clean energy power generation technologies in the 21st century. Fuel cells are especially suitable for use as a power source for automobiles. Fue...

AI Technical Summary

Problems solved by technology

However, the oxidation kinetics of formic acid at the anode of the direct formic acid fuel cell is slow, and the catalyst is easily deactivated. The expensive anode catalyst is a major factor restricting the commercialization of fuel cells.

Now, palladium carbon and platinum carbon are the most widely used catalysts commercially, but due to the high price of palladium carbon and platinum carbon, the activity per unit mass is low, and it is easy to decay and deactivate during use. Urgent problems to be solved in large-scale commercialization of fuel cells

The solution so far is to use palladium-based alloy or platinum-based alloy catalysts to replace single-component palladium-carbon and platinum-carbon catalysts. Although this method can improve the activity and stability of the catalyst to a certain extent, compared with the requirements of commercial applications, there is still a big gap

It is worth noting that the activity of the currently reported electrocatalysts will gradually decrease during the cycle test, because carbon monoxide, an intermediate product in the electrocatalytic process of formic acid, will poison the catalyst material, which is an important factor restricting the stability of the electrocatalyst.

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