Dynamic Reconstruction of Yttrium Oxide-Stabilized Cobalt-Loaded Carbon-Based Catalysts During Thermal Ammonia...

Hydrogen production from the decomposition of ammonia is considered an effective approach for addressing challenges associated with hydrogen storage and transportation. However, their relatively high energy consumption and low efficiency hinder practical multi-scenario applications. In this study, Y₂O₃-stabilized catalysts with Co-loaded onto porous nitrogen-doped carbon (Y₂O₃-Co/NC) are synthesized by pyrolysis of Y(NO₃)₃-modified ZIF-67 under an inert atmosphere, followed by annealing in a reducing environment. The introduction of Y₂O₃ enhanced the recombination and desorption of N atoms and facilitated the gradual dehydrogenation of NH_x on the catalyst surface, resulting in improved catalytic activity for the thermal decomposition of ammonia. Benefitting from the electron-donating properties of Y₂O₃ and N-doped carbon, the optimized catalyst achieved a remarkable NH₃ conversion efficiency of 92.3% at a high gas hourly space velocity of 20 000 cm³· $$ ·h^-1 with an encouraging H₂ production rate of 20.6 mmol· $$ ·min^-1 at 550 °C. Moreover, the synthesized catalyst undergoes a fast-dynamic reconstruction process, resulting in exceptionally stable catalytic activity during the thermal decomposition of ammonia, rendering it a promising candidate for carbon-free energy thermocatalytic conversion technology.