RSCF №22-13-00035

(2022-2024)

Annotation

The main aim of the proposed project is the development of new active and stable electrocatalysts for the oxygen reduction reaction (ORR). The catalysts will be based on nitrogen-doped carbon nanomaterials. The key point of the project is the modification of the doped nanomaterials by anionic groups. This modification allows solving two problems: preventing agglomeration of the nanomaterials and immobilization of modified nanomaterials in the matrix of conducting polymer. To achieve the aim, doped carbon materials will be obtained, anionic groups will be grafted on the doped carbon materials and the modified materials will be immobilized into a conducting polymer matrix. Separately, each of these stages is described in the literature, which assures the attainability of the proposed aim. However, the authors of the project are not aware of examples of the combined application of these approaches to create catalytic systems. The main reason for using the new approach is the need to use doped as well as modified materials, however, there is a technical problem. On the one hand high temperature pyrolysis is an effective method to obtain doped nanomaterials, but anionic groups will be removed by high temperature conditions. On the other hand, the most common method for sulfonating carbon materials is direct treatment with harsh sulfonating agents such as sulfuric acid, oleum, or chlorosulfonic acid. This method is simple, inexpensive, and scalable, and is well suited for highly amorphous undoped carbon materials. However, the method can't be applied for doped carbon nanomaterials due to the destruction of the materials. Therefore, in the project two independent new approaches to soft modification by anionic groups will be used. The first approach consists of chemical sulfonation under mild conditions through diazo compounds, the second consist of bombardment of materials with ion beams. The development of such techniques will allow obtaining anionically modified nanomaterials. The materials will be immobilized in a polymer matrix for preparation of the new effective ORR catalysts.

Expected results

Obtaining new active and stable electrocatalysts for the oxygen reduction reaction (ORR) is the purpose of the project. Nitrogen-doped carbon nanomaterials (graphene, carbon nanotubes) have high activity in the reaction. However, the stability of the nanomaterials is low. The catalytic activity of the materials is decreased during operation due to agglomeration and leaching of nanoparticles. Therefore, the development of methods forthe preparation of stable dispersions of ORR catalysts will bethe main results ofthe project. The catalysts will consistof sulfonated nitrogen-doped carbon nanomaterials, which will be immobilized to a conducting polymer matrix. Sulfonation of carbon materials is a well-known process forthe synthesis of graphene/polymer electrode materials for chemical power sources. According to literature data, we may conclude thatthe catalysts based on polymer-inorganic composites will have high efficiency and stability. The expected half-wave potential in ORR will be higher than 0.9 V vs RHE. It is proposed thatthe obtained composite catalysts will be applied as a replacement for platinum systems in low-temperature fuel cells and metal-air batteries. The obtained results can provide development of new technology in hydrogen energy devices. In accordance withthe Orderofthe Governmentofthe Russian Federationof 09.06.2020 No. 1523-r No. "On Approvalofthe Energy Strategyofthe Russian Federationforthe Period up to 2035", it is planned to stimulate theresearchand developmentof hydrogen energy both in termsofthe exportofcomponents, finished products and technologies, and in termsof consumptioninthe domestic market, a significant shareof which shouldbe occupied by fuel cells. In accordance withthe order, hydrogen production is expected to grow to 0.2 million tons by 2024, and up to 2 million tons in 2035. Therefore, themodernizationand developmentof new efficient RVC catalysts used in fuel cellsis becomingan urgentandsocially significant task