The (photo)electrochemical nitrogen reduction reaction for ammonia (NH₃) production is an appealing alternative to the traditional high-energy Haber–Bosch reaction. However, the future of this approach is bleak because of the ultralow N₂ solubility and the nonpolar NN bond causing the NH₃ yield and selectivity to be unsatisfactory. Nitrate electroreduction (NORR) into NH₃ brings promise for the future landscape of NH₃ electrosynthesis due to the low NO bond energy and high nitrate solubility. Here, we report a highly efficient Pd-doped TiO₂ nanoarray electrode for NH₃ production from the NORR. With weakened adsorption abilities to the intermediates induced by Pd introduction, the catalyst delivers a record-high NH₃ yield of 1.12 mg cm⁻² h⁻¹ (or 0.066 mmol cm⁻² h⁻¹), an impressive NH₃ faradaic efficiency (FE) of 92.1%, and an exceptional nitrate conversion of 99.6%. Considering an eight-electron nitrate-to-ammonia reaction and the excellent electrocatalytic activity of Pd/TiO₂, we, for the first time, propose and develop a Zn–nitrate battery system, which delivers striking bifunctionality for harnessing the electrons related to the NORR to generate electricity and directly produce NH₃, specified by a power density of 0.87 mW cm⁻² and a high NH₃ FE of 81.3%. Our work not only verifies the positive effect of Pd doping on facilitating the NORR, but also demonstrates a galvanic nitrate-based cell providing a promising strategy for NH₃ production and broadening the field of Zn-based batteries.

中文翻译：

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Pd掺杂减弱中间吸附促进TiO2纳米阵列上的电催化硝酸盐还原用于氨生产和硝酸锌电池的能源供应

用于氨 (NH ₃ ) 生产的（光）电化学氮还原反应是传统高能 Haber-Bosch 反应的一种有吸引力的替代方法。然而，由于超低的 N ₂溶解度和非极性 N N 键导致 NH ₃产率和选择性不令人满意，这种方法的未来是黯淡的。由于低 NO键能和高硝酸盐溶解度，将硝酸盐电还原 (NORR) 还原为 NH ₃为 NH ₃电合成的未来前景带来了希望。在这里，我们报告了一种用于 NH _{3 的}高效 Pd 掺杂的 TiO ₂纳米阵列电极从 NORR 生产。与被减弱吸附能力由钯引入引起的中间体，催化剂提供了一个记录高NH ₃的产率为1.12毫克厘米^-2 ħ ^-1（或0.066毫摩尔厘米^-2 ħ ^-1），一个令人印象深刻的NH ₃的法拉第效率（ FE) 为 92.1%，硝酸盐转化率为 99.6%。考虑到硝酸盐到氨的八电子反应和 Pd/TiO ₂优异的电催化活性，我们首次提出并开发了一种锌-硝酸盐电池系统，该系统具有惊人的双功能性，可利用与NORR发电并直接产生NH ₃，由 0.87 mW cm ^-2的功率密度和81.3%的高 NH ₃ FE 指定。我们的工作不仅验证了 Pd 掺杂对促进 NORR 的积极影响，而且还证明了硝酸原电池为 NH ₃生产和拓宽锌基电池领域提供了有前景的策略。