The Haber–Bosch process, the traditional method of ammonia synthesis, uses hydrogen derived from steam reforming of hydrocarbons; and involves harsh operating conditions of high temperatures (300–600 °C) and pressures (200–400 atm), expending a vast amount of energy each year. Recently, there has been a lot of interest in the electrochemical nitrogen reduction process (NRR) to NH₃, which is inspired by natural microbial nitrogen fixation. However, the stable NN violent hydrogen evolution reaction hindered the development of the NRR. In comparison, the electrocatalytic nitrate reduction reaction (NO₃RR) has significant advantages. The much lower dissociation energy of NO (204 kJ mol⁻¹) is required; nitrate is widespread in surface water. Herein, an electrocatalyst loaded with Ni onto CoZn@ZIF by a simple impregnation method is reported, which possesses a nitrogen-doped graphitic carbon structure after pyrolytic carbonization. Detailed experiments showed that the NiCo-NC catalyst significantly accelerated the NO₃RR compared to Co-NC. NiCo-NC exhibited remarkable NO₃RR activity. At −0.6 V and −1.1 V, ammonia yields of 5.01 mg cm⁻² h⁻¹ and 10.12 mg cm⁻² h⁻¹ were obtained, with FEs reaching 92.75% and 96.65%, respectively. The catalyst showed excellent electrochemical stability in 24-hour electrolysis experiments and five-cycle stability tests. Meanwhile, ¹⁵N isotope labeling experiments further verified the source of N in NH₄⁺ from NO₃⁻.

中文翻译：

---

负载镍的Co-NC催化剂促进电催化硝酸盐还原成氨


哈伯-博世工艺是传统的氨合成方法，使用来自碳氢化合物蒸汽重整的氢气；并且涉及高温（300-600°C）和高压（200-400 atm）的恶劣工作条件，每年消耗大量能源。最近，人们对受自然微生物固氮作用启发的电化学氮还原过程（NRR）生成NH ₃产生了很大的兴趣。然而，稳定的N N剧烈的析氢反应阻碍了NRR的发展。相比之下，电催化硝酸盐还原反应（NO ₃ RR）具有显着的优势。 N 的解离能低得多 需要O (204 kJ mol ^-1 )；硝酸盐广泛存在于地表水中。本文报道了一种通过简单的浸渍方法将Ni负载到CoZn@ZIF上的电催化剂，该催化剂在热解碳化后具有氮掺杂的石墨碳结构。详细的实验表明，与Co-NC相比，NiCo-NC催化剂显着加速了NO ₃ RR。 NiCo-NC表现出显着的NO ₃ RR活性。在-0.6 V和-1.1 V下，氨收率分别为5.01 mg cm ^-2 h ^-1和10.12 mg cm ^-2 h ^-1 ，FE分别达到92.75%和96.65%。该催化剂在24小时电解实验和五次循环稳定性测试中表现出优异的电化学稳定性。 同时， ¹⁵ N同位素标记实验进一步验证了NH ₄ ⁺中N的来源为NO ₃ ^- 。