Development of active and non-noble metal-based catalyst for H₂ production via NH₃ decomposition is crucial for the implementation of NH₃ as a H₂ carrier. Co-based catalysts have received increasing attention because of its high intrinsic activity and moderate cost. In this work, we examined the effect of BaNH, CaNH and Mg₃N₂ on the catalytic activity of Co in the NH₃ decomposition reaction. The H₂ formation rate ranks the order as Co-BaNH > Co-CaNH > Co-Mg₃N₂ ≈ Co/CNTs within a reaction temperature range of 300–550 °C. It is worth pointing out that the H₂ formation rate of Co-BaNH at 500 °C reaches 20 mmol_H2 g_cat^–1 min^–1, which is comparable to those of the active Ru/Al₂O₃ (ca. 17 mmol_H2 g_cat^–1 min^–1) and Ru/AC (21 mmol_H2 g_cat^–1 min^–1) catalysts under the similar reaction conditions. In-depth research shows that Co-BaNH exhibits an obviously higher intrinsic activity and much lower E_a (46.2 kJ mol^–1) than other Co-based catalysts, suggesting that BaNH may play a different role from CaNH, Mg₃N₂ and CNTs during the catalytic process. Combined results of XRD, Ar-TPD and XAS show that a [Co–N–Ba]-like intermediate species is likely formed at the interface of Co metal and BaNH, which may lead to a more energy-efficient reaction pathway than that of neat Co metal for NH₃ decomposition.

通过NH ₃分解生产H ₂的活性和非贵金属基催化剂的开发对于将NH ₃用作H ₂载体至关重要。钴基催化剂因其高内在活性和适中的成本而受到越来越多的关注。在这项工作中，我们研究了BaNH，CaNH和Mg ₃ N ₂对Co在NH ₃分解反应中的催化活性的影响。为H ₂形成速率行列的顺序为联合迪班>联合CANH>共同的Mg ₃ Ñ ₂ ≈的Co /反应温度范围300-550℃的范围内的CNT。值得指出的是H ₂500°C时Co-BaNH的生成速率达到20 mmol _H2  g _cat ^–1  min ^–1，与活性Ru / Al ₂ O _3的形成速率相当（约17 mmol _H2  g _cat ^–1  min ^–1）。和Ru / AC（21 mmol _H2  g _cat ^–1  min ^–1）催化剂在相似的反应条件下。深入的研究表明，Co-BaNH的内在活性明显高于其他Co-基催化剂，而E _a（46.2 kJ mol ^–1）则要低得多，这表明BaNH可能起与CaNH，Mg不同的作用。₃ N ₂和碳纳米管在催化过程中。XRD，Ar-TPD和XAS的综合结果表明，在Co金属和BaNH的界面上可能形成[Co–N–Ba]状中间物，这可能导致比Co2的反应更节能的反应路径。用于NH ₃分解的纯Co金属。