Hydrogen energy has become the preferred option for global emission‑reduction and carbon‑neutrality initiatives. With stricter emission requirements and advances in hydrogen production and storage technologies, hydrogen is playing an increasingly prominent role in the global energy transition, giving rise to a new landscape of coordinated innovation across multiple industries. According to forecasts by the Hydrogen Council, hydrogen will account for 18 % of global final‑energy demand by 2050, and the hydrogen‑related market will exceed USD 2.5 trillion. China has initially built an industrial‑chain system covering hydrogen production, storage, transportation and application. Hydrogen internal‑combustion engines feature distinct strengths including zero‑carbon emissions, high efficiency, high reliability and low cost, making them one of the important pathways for hydrogen‑energy application.

Recently, Xu Yanni and Liu Hanru, deputies to the National People’s Congress, put forward proposals to encourage the development of hydrogen internal‑combustion engines. They called on enterprises and research institutions to invest in the development of hydrogen internal‑combustion engines and jointly push for full independent development of such engines. Hydrogen internal‑combustion engines can leverage existing internal‑combustion‑engine technologies and supporting supply chains. Conventional internal‑combustion engines can be retrofitted to burn hydrogen and achieve zero‑carbon emissions. Green hydrogen is produced via water electrolysis using renewable green power sources such as wind, solar, hydropower or geothermal energy. Therefore, hydrogen internal‑combustion engines are widely recognized by the industry as the most practically viable technical route for hydrogen deployment in automobiles. To seize this strategic opportunity, China should accelerate the layout of hydrogen‑internal‑combustion‑engine industrial chains and explore solutions for large‑scale hydrogen application on internal‑combustion engines.

In August last year, in its reply to Proposal No. 5736 submitted at the Fourth Session of the 13th National People’s Congress, the Ministry of Industry and Information Technology stated that it would study and promote support for hydrogen internal‑combustion engines. On December 3, the Ministry of Industry and Information Technology issued the *14th Five‑Year Plan for Green Industrial Development*, which once again proposed the development of hydrogen‑fuel gas turbines.

Engine manufacturers have fully recognized the unique advantages of hydrogen internal‑combustion engines. FAW Group, Weichai Power, GAC Group, Yuchai Machinery, SAIC Motor, Changan Automobile, Geely Auto and other enterprises have successively carried out relevant R&D work in this field.

Fuel cells use precious‑metal platinum as catalyst. Three core materials — proton‑exchange membranes, catalysts and bipolar plates — are costly, keeping overall expenses high. By contrast, hydrogen internal‑combustion engines draw on the technical and manufacturing foundations of conventional internal‑combustion engines. Over 90 % of their components can be reused directly. Their total cost is comparable to that of traditional fossil‑fuel internal‑combustion engines, amounting to merely one‑twentieth of that of fuel‑cell powertrain systems.

Fuel cells require hydrogen purity of no less than 99.97 %, whereas hydrogen internal‑combustion engines impose almost no purity requirements for hydrogen. As a result, hydrogen‑fuel costs for hydrogen internal‑combustion engines are far lower than those for hydrogen fuel cells.

Hydrogen fuel cells deliver zero emissions. Hydrogen internal‑combustion engines generate a certain amount of nitrogen‑oxide emissions from in‑cylinder combustion, yet such emissions are controllable. Hydrogen internal‑combustion engines equipped with high‑efficiency combustion and after‑treatment technologies can achieve near‑zero emissions.

Hydrogen fuel cells feature high efficiency and zero emissions, yet they come with high technical barriers, high costs and heavy reliance on supporting infrastructure. Hydrogen internal‑combustion engines retain the main structures and systems of conventional internal‑combustion engines and convert energy through combustion, with water as their primary product. They achieve thermal efficiency close to that of fuel cells and can deliver near‑zero emissions with prominent low‑cost advantages. Hence, hydrogen internal‑combustion engines are widely acknowledged by the automotive industry as the most practically meaningful technical option for hydrogen‑energy vehicle applications.