Electrocatalytic reduction of nitrite (NO₂⁻) is considered an effective method to solve its environmental pollution issue as well as sustainable ammonia (NH₃) synthesis under ambient conditions but still requires high-performance catalysts. Herein, self-supported monoclinic WO₂ nanoparticles with abundant oxygen vacancies (OVs) on a tungsten plate (WO₂/W) are demonstrated as a highly efficient electrocatalyst for selectively reducing NO₂⁻ to NH₃. In 0.1 M NaOH solution containing 0.1 M NO₂⁻, such an electrocatalyst achieves an excellent yield of 14 964.25 ± 826.06 μg h⁻¹ cm⁻² and high faradaic efficiency (FE) of 94.32 ± 1.15% at −0.9 V. Remarkably, the assembled Zn–NO₂⁻ battery delivers a high power density of 5.05 mW cm⁻² and simultaneously offers an abundant NH₃ yield of 1923.88 μg h⁻¹ cm⁻². Theoretical calculations reveal the critical role of OVs for WO₂ in the nitrite electrocatalytic reduction process and its possible reaction pathway.

中文翻译：

---

具有氧空位的 WO2 纳米颗粒：用于将亚硝酸盐转化为氨的高效电催化剂

亚硝酸盐 (NO ₂ ^- ) 的电催化还原被认为是解决其环境污染问题以及在环境条件下可持续合成氨 (NH ₃ ) 的有效方法，但仍然需要高性能催化剂。在此，在钨板上具有丰富氧空位 (OV) 的自支撑单斜 WO _{2纳米颗粒 (WO 2} /W) 被证明是一种高效的电催化剂，可选择性地将 NO ₂ ^-还原为 NH ₃。在含有 0.1 M NO ₂ ⁻的 0.1 M NaOH 溶液中，这种电催化剂实现了 14 964.25 ± 826.06 μg h ⁻¹ cm ^{−2的优异产率}在 −0.9 V 时法拉第效率 (FE) 为 94.32 ± 1.15%。值得注意的是，组装的 Zn–NO ₂ ^{−电池可提供 5.05 mW cm −2}的高功率密度，同时提供1923.88 μg h的丰富 NH _3产量^-1厘米^-2。理论计算揭示了OVs对WO ₂在亚硝酸盐电催化还原过程中的关键作用及其可能的反应途径。