A compact catalytic foam reactor for decomposition of ammonia by the Joule-heating mechanism

Ammonia (NH₃) is a viable hydrogen (H₂) carrier that allows storage and transport of H₂ using well-established infrastructure while maintaining high H₂ storage density. However, cracking NH₃ into H₂ is energy-intensive. Herein, direct Joule-heating of the NiCrAl foam catalyst support is suggested and demonstrated, to minimize heat transfer scale for lower reactor volume, higher efficiency and power density than previously reported reformers. The power density of 128 W/cm³_Reactor is achieved based on the lower heating value of H₂: this is 90% higher than previously reported microreactors. Also, even in a small-scale demonstration with a low internal volume of 7.7 cm³ and a high surface-area-to-volume ratio of 5.7 cm⁻¹, a high reforming efficiency of 69.2% is achieved with low catalyst loadings, showing the feasibility of the concept. The as-proposed reactor concept offers a strong prospect for facile adoption of the power-to-X scheme for numerous applications including H₂-fueled islanded networks, and decarbonized energy conversion.