Preparation method of catalyst with core-shell structure for low-temperature fuel cell

Abstract

The invention discloses a preparation method of a catalyst with a core-shell structure for a low-temperature fuel cell, belonging to the technical field of fuel cells. In the catalyst with the core-shell structure prepared with the preparation method, platinum is taken as a shell, a metal alloy consisting of more than one of metals including ruthenium, platinum, iron, cobalt, nickel, copper, tin, iridium, gold and silver is taken as an inner core, and the shell and the inner core are loaded on a carbon carrier. The preparation method comprises the following preparation steps of: reducing a metal chloride or a metal nitrate with a reducing agent, and forming a core on the carbon carrier with a large specific surface area; stabilizing the core; and precipitating Pt on a core layer with a impregnation reduction method, a high-pressure organic sol method, a microwave method or an electrodeposition process to form the catalyst with the core-shell structure. Due to the adoption of the preparation method, the utilization ratio of noble metal platinum is increased, the cost of an electro-catalyst is reduced effectively, and the methanol oxidizing capability and oxygen reducing activity of the obtained catalyst are increased by 10.8 times and 8.7 times in maximum respectively in comparison to the mass ratio and activity of a commercial JM4100Pt / C catalyst.

Description

technical field [0001] The invention relates to the field of fuel cells, in particular to a method for preparing a core-shell structure catalyst used in low-temperature fuel cells. Background technique [0002] With the increasingly severe energy problems and environmental problems caused by burning coal and other fossil fuels, the research and development of hydrogen energy and fuel cells have been paid more and more attention by governments and scientific circles all over the world. Due to its rich and diverse fuel sources, high energy conversion efficiency, and low environmental impact (zero or low emission), fuel cells are considered to be a new energy technology that is most likely to replace existing energy on a large scale. It is one of the important technical means for energy problems and serious environmental pollution problems caused by burning fossil energy. In addition, low-temperature fuel cells in fuel cells are known as the most promising type of fuel cells f...

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Problems solved by technology

[0004] Chinese patent application document CN101890368A discloses a "preparation method of carbon-supported highly active gold or gold-platinum alloy or gold-core-platinum-shell structure nanocatalyst", that is, using a self-assembly method to modify porous carbon with π-π bonds of modified chemical reagents Obtain mercapto-functionalized carbon black as a carrier, and then deposit gold nanoparticles or gold-platinum alloy or gold-core-platinum-shell structure nanoparticles on the surface of mercapto-functionalized carbon black to obtain highly active gold or gold-platinum alloy Or gold-core-platinum-shell structure nano-carbon-supported catalysts, but this method requires a long cycle to prepare catalysts, and the prepared catalyst particles are relatively large

While giving full play to the advantages of high instantaneous peak current of pulse electrodeposition, this method overcomes the difficulty in controlling the size of M core grains and MPt grains caused by the charge and discharge of electric double layer capacitance during the two-step pulse electrodeposition process. the disadvantages of

However, this method for preparing catalysts with a core-shell structure still has a series of problems such as cumbersome process, too many influencing factors, and difficulty in controlling the metal mass ratio of the core to the shell.

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