<p>Ammonia decomposition is a promising route for carbon-free hydrogen production, However, the development of efficient and durable non-noble metal catalysts remains challenging owing to issues such as metal sintering. Herein, we demonstrate that precursor morphology engineering is an effective strategy for addressing this limitation. By modulating the solvent system, three distinct ZIF-67 morphologies (platelet (P-), sheet (S-), and rhombic dodecahedron (R-)) were synthesized and subsequently pyrolyzed into the corresponding Co@NC catalysts. Among them, R-Co@NC exhibited a superior hierarchical micro-mesoporous N-doped carbon framework with homogeneously dispersed Co nanoparticles and abundant Co-N active sites, leading to superior catalytic performance: 82.43% NH₃ conversion at 500 ℃ and a hydrogen production rate of 27.58 mmol H₂ g⁻¹ cat min⁻¹. Moreover, R-Co@NC exhibited exceptional stability, maintaining ~ 89% conversion over 200&#xa0;h at 600 ℃. Combined with the conductive carbon framework, the synergistic effect between metallic Co and Co-N sites facilitate N-H bond cleavage and N-N coupling. This study presents the importance of controlling precursor morphology in the design of advanced catalysts for ammonia decomposition.</p> Graphical Abstract <p></p>