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

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, YO-stabilized catalysts with Co-loaded onto porous nitrogen-doped carbon (YO-Co/NC) are synthesized by pyrolysis of Y(NO)-modified ZIF-67 under an inert atmosphere, followed by annealing in a reducing environment. The introduction of YO enhanced the recombination and desorption of N atoms and facilitated the gradual dehydrogenation of NH on the catalyst surface, resulting in improved catalytic activity for the thermal decomposition of ammonia. Benefitting from the electron-donating properties of YO and N-doped carbon, the optimized catalyst achieved a remarkable NH conversion efficiency of 92.3% at a high gas hourly space velocity of 20 000 cm· ·h with an encouraging H production rate of 20.6 mmol· ·min 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.