Enhanced Low-Temperature Ozone-Assisted Catalytic Oxidation of Propane Over Cu–Mn Bimetallic Oxides

Liquid carriers are expected to play a pivotal role in the large-scale transport of hydrogen. Among the various candidates, ammonia emerges as a carbon-free molecule, supported by mature, cost-effective infrastructure. In decentralized electrical power generation, ammonia storage can be integrated directly with fuel cells or indirectly via cracking and separation units to feed proton exchange membrane fuel cells. The overall energy efficiency of such integrated systems is strongly influenced by the interaction between the unit operations and the potential to couple exothermic and endothermic processes for energy recovery. This review analyzes recent developments in ammonia-based systems integrated with fuel cells, focusing on the characteristics and interaction of key units from an integration and performance perspective. Critical gaps are identified that currently limit system efficiency and deployment. Particular attention is devoted to nitrogen and ammonia separation, which significantly affects fuel cell performance and overall system efficiency depending on the fuel cell type and operating conditions. Integration with afterburners and gas turbines is discussed as a strategy to enhance overall energy output. Finally, the review addresses electrification opportunities and safety concerns, highlighting potential hazards, accidental scenarios, and mitigation strategies to support the safe and sustainable design of decentralized ammonia-based power systems.