Hydrogen fuel cell ship is an important way to realize green shipping, and the safety of hydrogen fuel ship is primary issue that shall be concerned. H2 gas sensors can provide online monitoring of H2 concentration and it is an effective mean to insure safety of hydrogen fuel. In this study, an amperometric electrochemical H2 gas sensor based on room-temperature ionic liquid was developed, which was expected to be applicable to monitoring of H2 concentration in the hydrogen fuel cell ship. A threeelectrode H2 gas sensor was fabricated by using room-temperature ionic liquid N, N, N-trimethyl-Nbutanesulfonic acid ammonium hydrogen sulfate ([TMBSA][HSO4]) as electrolyte and using platinum black as catalyst. The H2 gas sensor not only had the advantages of the conventional aqueous electrolyte sensor, such as high sensitivity, fast response, and the linear relationship between the response current and the concentration of H2, but also overcame the problem that the conventional electrochemical gas sensor cannot be applied to high humidity environment. After storage in high-humidity environment (98% RH) for three weeks, the sensor had stable performances, with current signal drift less than 2.25%. The sensor has a good potential application prospect in ships with high temperature and humidity environment.

The high quality development of fuel cell ship industry is of great significance for China to achieve carbon dioxide peaking and carbon neutrality. The research of fuel cell ships in China is still in its early stage and faces many challenges to achieve industrialization. In this paper, the types and characteristics of fuel cells are introduced, and the fuel cell types suitable for marine applications are identified. Then, the research status of fuel cell ship projects in China and abroad is introduced. By comparing fuel cell ship projects, the gap between domestic and foreign fuel cell ship projects is discussed. Finally, in view of the existing problems of fuel cell ships in China, some suggestions for the development of marine hydrogen fuel cells in China are put forward, and the future development of marine hydrogen fuel cell technology in China is prospected.