Electrochemical Characterization of Protonic Ceramic Electrolysis Cells for Enhanced Ammonia Synthesis

Abstract

Ammonia has attracted significant attention as a key hydrogen carrier for the next-generation hydrogen economy because of its high hydrogen content and ease of storage and transportation. Currently, industrial ammonia production mainly relies on the Haber-Bosch process, which synthesizes ammonia from hydrogen and nitrogen under high temperature and pressure. However, this process is highly energy-intensive and produces substantial greenhouse gas emissions because it commonly uses hydrogen derived from fossil fuels. In this regard, proton-conducting ceramic electrolysis cells （PCECs） have emerged as a promising electrochemical platform for sustainable ammonia synthesis because they can generate reactive hydrogen species from water electrolysis and operate at intermediate temperatures. In this study, ammonia synthesis was investigated using PCECs based on a BaZr0.4Ce0.4Y0.1Yb0.1O3- proton-conducting electrolyte. The electrochemical performance of the cells was evaluated through impedance spectroscopy and current-voltage measurements under nitrogen and nitric oxide-containing atmospheres. Ammonia formation was then analyzed as a function of operating temperature and applied bias. It was suggested that proton-conducting ceramic electrochemical cells can provide an effective pathway for ammonia synthesis by coupling water electrolysis with nitrogen-containing gas reduction. These findings demonstrate the potential of PCEC-based systems as a sustainable alternative to conventional ammonia synthesis processes.