High purity, self-sustained, pressurized hydrogen production from ammonia in a catalytic membrane reactor

Modeling-aided coupling of catalysts, conditions, membranes, and reactors for efficient hydrogen production from ammonia

“…In our previous studies, we investigated the ammonia decomposition reaction with two catalysts, Ru-K/CaO and Co-Ba/CeO 2 . 11,70,74 The Co-based catalyst with 80/20 molar Co/Ce ratio was synthesized by the co-precipitation method, followed by the addition of Ba (0.5 wt% Ba) as a promoter using the incipient wetness impregnation method. Ru-K/CaO was prepared using the impregnation method, followed by a pyrolysis step and final incorporation of potassium using the same method (10 wt% K).…”

“…6.0 kW h kg −1 for compression of H 2 to 70 MPa, which leads to approximately 1.3 kg of CO 2 kg −1 of H 2 ). 10 The energy analysis in our previous work 11 allowed us to prove that the efficiency of the whole process (including the postcompression stage up to 350 bar) would drop from 77.7% to ∼68-73%, when hydrogen in the permeate is produced at 1-20 bar, respectively, thus highlighting the significance of developing reliable kinetic models at high pressure.…”

Elucidating the rate-determining step of ammonia decomposition on Ru-based catalysts using ab initio-grounded microkinetic modeling

“…To circumvent these limitations, reactors fitted with H 2selective membranes have been designed and experimentally tested. The selective and continuous removal of the generated H 2 , delivered between 1 and 15 bar, 2,6,7 shifts the equilibrium toward the products. Moreover, the separation of pure H 2 from the generated nitrogen (N 2 ) or unreacted NH 3 is required because both impurities are detrimental to H 2 use and further applications.…”

Y-Doped BaCeO3 Perovskite-Supported Ru Catalysts for COx-Free Hydrogen Production from Ammonia: Effect of Strong Metal–Support Interactions

“…The decomposition of NH 3 to produce H 2 (NH 3 ↔ N 2 + 1.5H 2 ) is an endothermic reaction (Δ H 298 K = 46 kJ·mol –1 ), and the thermodynamic equilibrium conversion is higher than 99% under ambient pressure at 400 °C. − Among the various active species, Ru has exhibited promising performance in the NH 3 decomposition. − Based on previous mechanistic studies, the associative desorption of N 2 from the Ru catalyst is the rate-limiting step in the overall catalytic cycle. − It is extensively recognized that an increase in the electron density of the Ru species promotes associative N 2 desorption . Notably, Ru catalysts supported on electron-rich basic metal oxides, such as MgO, CaO, and CeO 2 , exhibited superior activity compared to those supported on acidic materials. − Based on this perspective, the regulation of the interaction of Ru species with electron-rich basic supports and the formation of the interface, which donates electrons from the support to the Ru species, are essential factors required to facilitate N 2 desorption and improving the catalytic performance for NH 3 decomposition …”