In March 2022, the "Medium and Long-Term Plan for Hydrogen Energy Industry Development (2021-2035)" was promulgated, and the hydrogen energy industry was officially included in the national medium and long-term energy development system. In the context of carbon peaking and carbon neutrality, it is imperative to change China's energy structure, and hydrogen energy will become an indispensable energy carrier and energy storage method in the future.

At present, the vast majority of domestic hydrogen sources come from fossil energy hydrogen production and industrial by-product hydrogen production, but only hydrogen produced through electrolysis of water by renewable energy can be considered green hydrogen, free of greenhouse gas and harmful gas emissions, and high in hydrogen purity , is the cleanest way to produce hydrogen.

In April 2023, the European Parliament supports the EU Carbon Market Reform (EUETS) program and passes the EU Carbon Border Adjustment Mechanism (CBAM), agreeing to impose carbon dioxide costs on imported steel, cement, aluminum, fertilizers, electricity and hydrogen. The inclusion of hydrogen energy in the CBAM Act means that only green hydrogen in hydrogen energy can be exempted from tariffs. It is expected that the passage of the bill will further stimulate the proportion of green hydrogen consumption in my country and promote the development of the green hydrogen market mechanism.

According to the different materials of the diaphragm of the electrolyzer, hydrogen production by electrolysis of water at room temperature is usually divided into hydrogen production by alkaline water (AWE), hydrogen production by proton exchange membrane (PEM), and hydrogen production by anion exchange membrane (AEM).

Among them, AWE technology is the most mature, simple process, and the highest degree of commercialization, but its efficiency is relatively low, power consumption is large, and it cannot be directly connected to renewable energy because it is difficult to quickly start or change load. Compared with AWE, PEM technology has higher current density, higher hydrogen production efficiency, higher hydrogen purity, small system footprint, fast start-up, and direct connection with renewable energy. However, the raw material proton exchange membrane relies on imports, the catalyst uses precious metal materials, and the bipolar plate uses stainless steel titanium or titanium plate, so the production cost remains high, breakthrough improvement cannot be achieved in a short period of time, and the service life is significantly lower than AWE.

AEM has the advantages of both AWE and PEM. It has high efficiency, low cost, small size, quick startup and can be directly connected to renewable energy. It is considered to be the most potential next-generation energy-saving hydrogen production method.

The structure of AEM electrolyzer is similar to that of PEM electrolyzer, and the core component is membrane electrode assembly (MEA): MEA mainly includes anion exchange membrane, ionomer, anode and cathode catalyst layer. Generally, pure water or low-concentration alkaline solution is used as the electrolyte. The Anion Exchange Membrane is an important component in the AEM electrolyzer setup, its role is to conduct OH- from the cathode to the anode while blocking the direct transfer of gas and electrons between the electrodes. In practical applications, anion exchange membranes are required to have sufficient mechanical strength, high thermal stability, chemical stability, ion conductivity, and barrier effects between electrons and gases.

The hydrogen production principles of the three technologies for hydrogen production by electrolysis of water are basically the same, involving two half-reactions, the cathodic hydrogen evolution reaction (HER) and the anode oxygen evolution reaction (OER). The hydrogen evolution reaction and oxygen evolution reaction in the actual electrolysis process deactivate the overpotential and overcome the energy barrier of the original reaction, resulting in high energy consumption of the reaction. The oxygen evolution reaction involves a multi-electron transfer process, and the kinetic reaction is slow, which is a key factor restricting the efficiency of the entire water electrolysis device. In order to enhance the reactivity and reduce energy consumption, it is necessary to load catalysts on the electrodes. Compared with PEM, AEM operates in a non-corrosive, weakly alkaline environment, and uses cheap non-precious metal catalysts and hydrocarbon membranes, which can significantly reduce equipment costs.

AEM has not yet entered large-scale commercialization and is still in the introduction period, but the development process has exceeded expectations. The factors limiting its large-scale development mainly come from two aspects: one is that the stability of anion exchange membrane, ion conductivity and hydroxide selectivity need to be further improved. The second is that the electrode catalytic material needs further breakthroughs, so that it can effectively overcome the energy barrier in the reaction process, improve the reaction efficiency, and reduce the power consumption in the hydrogen production process.

In recent years, with the rapid development of anion exchange membranes, the stability and reliability of the membranes have been greatly improved, which provides the possibility for the commercialization of AEM hydrogen production. At present, the main suppliers of AEM membranes include Dioxide Materials in the United States, Fumatech, Evonik in Germany, and Ionomr Innovations in Canada. EPC Energy Technology (Shanghai) Co., Ltd. also provides AEM membrane processing and sales. In addition, EPC Energy Technology (Shanghai) Co., Ltd. provides AEM water electrolysis hydrogen production cells, test fixtures and other related equipment to help universities and enterprises develop AEM technology and promote the large-scale commercialization of AEM electrolysis water hydrogen production technology .