What progress has been made in research on the use of three-dimensional graphene platinum catalyst in fuel cells

Recently, the research group Wang Qi of the Institute of Applied Plasma Physics of Hefei Institute of Physical Sciences of the Chinese Academy of Sciences made progress in methanol oxidation reaction. The relevant content was published in Applied Surface Science.

The principle of direct methanol fuel cell (DMFC) is that during the Redox reaction, the methanol of the anode loses electrons under the action of a catalyst and passes through the external circuit to the cathode. At the same time, hydrogen ions (acidic electrolytes) are transferred from the anode to the cathode through the electrolyte membrane, and the oxygen of the cathode is then catalyzed to reduce to give electrons to form a current loop and provide electrical energy. Catalysts are very important to the methanol oxidation reaction of the anode. In recent years, the related research has been more and more in-depth, mainly from the aspects of improving the utilization rate of precious metal catalysts, modifying carriers and preparing alloy catalysts to improve the ability to resist poisoning. Platinum (Pt) is a valuable metal catalyst with excellent performance and has been paid attention to by researchers. The carrier carrying platinum nanoparticles often has a great influence on the final catalytic performance. Graphene oxide is often used as a carrier for precious metals. However, direct use of graphene oxide as a carrier does not achieve the desired electrochemical performance test.

The researchers assembled graphene (GO) oxide and carbon nanotubes (CNTs) to form a three-dimensional structure and then loaded platinum. The three-dimensional graphene-carbon nanotubes catalyst (Pt/GNTs) with a large specific surface area can be obtained by hydrogen plasma discharge, which has excellent methanol oxidation catalytic properties. The advantages of this technical route synthesis GO and CNTs are that three-dimensional composite structures are formed by self-assembly, which increases the specific surface area and is more conducive to the distribution of platinum nanoparticles. Subsequently, the researchers prepared a series of different GO and CNTs quality ratios in the experiment(GO: CNTs = 0:1, 1:6, 1:4, 1:2, 1:1, 2:1, 4:1, 6:1 and 1:0) catalysts, the results found that GO: CNTs = 1:2 had the best catalytic properties for methanol, and the current density was as high as 691.1 mA/mg, which was 87.7 % higher than that of commercial platinum carbon catalysts. %, It is also superior to most of the other catalysts that have been reported and maintains a high current density after the 3600s CA test. This study is of great significance to the preparation of highly efficient catalyst for methanol oxidation and provides a new way of thinking for the preparation of three-dimensional graphene carriers.

The research work was supported by the National Natural Science Foundation, the Anhui Outstanding Youth Science Fund, the Youth Promotion Association of the Chinese Academy of Sciences, and the Dean's Fund of the Hefei Research Institute.

The page contains the contents of the machine translation.