Hydrogen production by ammonia decomposition reveals great advantages in the utilization of hydrogen. Low-cost, efficient and stable transition metal catalysts are the key for the ammonia decomposition reaction. Using multi-component promoters adjust the electronic and geometric structures of bulk catalysts, which might be an effective approach for obtaining non-noble metal catalysts with excellent performance. In this work, CeO₂–Al₂O₃ bi-promoters were used and significantly improved the catalytic performance of bulk cobalt catalysts. The optimized CoCeAlO_x catalyst achieved 94.3% and 65.3% NH₃ conversion at 550 °C and 500 °C (GHSV = 30 000 mL g_cat⁻¹ h⁻¹), respectively, and exhibited strong stability within 200 h. It was found that the interaction between Co–CeO₂–Al₂O₃ effectively inhibited the aggregation of the Co⁰ active species, which enormously promoted the catalytic activity and stability of CoCeAlO_x. CeO₂–Al₂O₃ bi-promoters adjusted the surface properties of catalysts, bringing suitable NH₃ adsorption and N₂ desorption, and suppressing the hydrogen poisoning significantly. This work provided a reliable strategy for the construction of high-efficiency catalysts working under the harsh conditions for ammonia decomposition.

中文翻译：

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CeO2-Al2O3促进氨分解的高效钴催化剂


氨分解制氢在氢气的利用方面显示出巨大的优势。低成本、高效、稳定的过渡金属催化剂是氨分解反应的关键。使用多组分促进剂调节本体催化剂的电子和几何结构，这可能是获得性能优良的非贵金属催化剂的有效途径。在这项工作中，使用了CeO ₂ –Al ₂ O ₃双促进剂并显着提高了块状钴催化剂的催化性能。优化后的CoCeAlO _x催化剂在550 °C和500 °C (GHSV = 30 000 mL g _cat ^-1 h ^-1 )下分别实现了94.3%和65.3%的NH ₃转化率，并在200 h内表现出很强的稳定性。研究发现Co-CeO ₂ -Al ₂ O ₃之间的相互作用有效抑制了Co ⁰活性物种的聚集，从而极大地提高了CoCeAlO _x的催化活性和稳定性。 CeO ₂ -Al ₂ O ₃双促进剂调节催化剂的表面性质，带来合适的NH ₃吸附和N ₂解吸，显着抑制氢中毒。这项工作为构建在恶劣的氨分解条件下工作的高效催化剂提供了可靠的策略。