While electrochemical nitrate reduction to ammonia represents a promising route for water treatment and ammonia generation, one critical challenge in the field is the need for high-concentration supporting electrolytes in this electrochemical system. Here we report a three-chamber porous solid electrolyte reactor design coupled with cation shielding effects for efficient nitrate reduction reaction without supporting electrolytes. By feeding treated water from the cathode chamber to the middle porous solid electrolyte layer, we can realize an alkali metal cation shuttling loop from the middle layer back into the cathode chamber to boost the nitrate reduction selectivity and suppress the hydrogen evolution side reaction. This reactor system can deliver high ammonia Faradaic efficiencies (>90%) at practical current densities (>100 mA cm⁻²) under a typical wastewater nitrate concentration of 2,000 ppm, enabling a high-purity water effluent and NH₃(g) as products with no need for electrolyte recovery processes.

虽然电化学硝酸盐还原成氨是水处理和氨生成的一种有前途的途径，但该领域的一个关键挑战是该电化学系统需要高浓度的支持电解质。在这里，我们报告了一种三室多孔固体电解质反应器设计，结合阳离子屏蔽效应，可在不支持电解质的情况下进行有效的硝酸盐还原反应。通过将处理过的水从阴极室输送到中间多孔固体电解质层，可以实现碱金属阳离子从中间层穿梭回阴极室的循环，从而提高硝酸盐还原选择性并抑制析氢副反应。该反应器系统可在典型废水硝酸盐浓度为 2,000 ppm 的情况下，在实际电流密度 (>100 mA cm ^-2 ) 下提供高氨法拉第效率 (>90%)，从而实现高纯度出水和 NH ₃ (g)无需电解液回收过程的产品。