Research on determination methods of trace ammonia in hydrogen for proton exchange membrane fuel cells

Ammonia is a critical indicator in the control of hydrogen impurities for proton exchange membrane fuel cells (PEMFCs). Both international and national standards strictly limit the ammonia content in hydrogen to within 0.1 μmol/mol. This paper summarizes the analytical methods for trace ammonia in hydrogen and conducts experimental comparative analyses of Gas Chromatography with Helium Ionization Detection (GC-HID) and Cavity Ring-Down Spectroscopy (CRDS). The results show that the CRDS method has a detection limit as low as 0.3 ppb, making it an accurate and feasible scheme for detecting trace ammonia in hydrogen used for fuel cell vehicles.