Comprehensive Review of Fuel-Cell-Type Sensors for Gas Detection

Gas detection based on the electrochemical cells has recently been paid attention. Because of the many applications of fuel cell sensors, several investigations have been done on fuel-cell-type sensors for gas detection. In this study, the research works are categorized based on the type of the most used fuel cell sensors, such as CO, H2, methanol, and ethanol. Moreover, the manufacturing, applied technologies and the operating conditions of them, including the limit of detection, detection ranges, and response time of the fuel cells, are reviewed and discussed. Finally, according to the previous investigations that have been carried out, the gaps are introduced and evaluated to prepare beneficial suggestions for future investigations. According to the literature, humidity management using Pt–Cu/C is one of the most used manufacturing methods for improving a fuel cell sensor's global and specific sensitivity. In addition, Nafion MEA with JM20 exhibits better detection performance of methanol sensors. Moreover, using nanotubes of multiwall carbon and nanoparticles of Pt–Pd in manufacturing shows proven improvements regarding the limit of detection and detection range for ethanol fuel cell sensors. PEFC-type sensor cells can improve the detection of CO to 0.2 ppm. Furthermore, the required targets for hydrogen fuel cell sensors in terms of safety and performance announced by the U.S. Department of Energy, for example, the response time of 1 s, are not reported in the open literature.