Low-Temperature Ammonia Synthesis with an In Situ Adsorber under Regenerative Reaction Cycles Surpassing Thermodynamic Equilibrium

Catalytic NH3 synthesis is a well-studied reaction, but its use in renewable energy storage difficult due to the need for small-scale production, requiring greatly reduced operating temperatures and pressures. inhibition on supported Ru catalysts becomes more prevalent at low temperatures, decreasing reaction rates. In addition, promoter species are prone oxidation lower further depressing rate. situ removal techniques have potential enhance under milder conditions combat both thermodynamic limitations, while regeneration of adsorber can potentially reactivate species. The deactivation event 5 wt % Ru/CeO2 (3.9 nm average particle size) was first explored detail, it found that slight Ce3+ major cause which easily restored by high-temperature H2 treatment. then mixed with zeolite 4A, substance showing favorable capacity mild conditions. adsorption significantly increased rate 200 °C kPa 75 N2, where from 128 565 μmol g–1 h–1 even conversions 0.25% (average yield 0.01%). temperature swings were utilized measure uptake 4A also provide reactivation Ru/CeO2. went beyond equilibrium achieving up 98%. This study sheds light kinetics provides insight into future designs utilizing similar techniques.