氨在农业、工业生产上有着重要的用途, 传统的哈伯法将氢气和氮气直接转化为氨, 消耗大量能源的同时对环境造成严重污染. 而电催化具有反应条件温和、选择性高、绿色环保等优势成为研究的热点. 其中开发有效选择性合成氨的廉价催化剂是关键. 本研究以废弃玉米秸秆为炭源, 植酸为磷源, 采用一步煅烧法成功制备出镍铁双金属磷化物负载的生物质炭催化剂(NiFeP/PBC), 表现出优异的电催化亚硝酸盐还原(eNO₂RR)合成氨性能, 在－0.2 V (vs. RHE) 电压下法拉第效率高达95.9%, 氨产率达到304.9 μmol•h⁻¹•cm⁻², 并具备良好的稳定性. 电化学原位红外研究表明, 催化剂在反应过程中生成NO、NH₂和NH₃等关键中间体, 且活性氢(*H)在还原过程中起重要作用. 该工作为废弃生物质的高值化利用和绿色电合成氨提供了新策略, 具有显著的环境和能源意义.

Ammonia holds crucial and widespread applications in modern agriculture and various industrial production sectors. The traditional Haber process directly converts hydrogen and nitrogen gases into ammonia, which consumes an enormous amount of energy while bringing about serious environmental pollution. In contrast, electrocatalysis boasts prominent advantages such as mild reaction conditions, high selectivity, and environmental friendliness, thus making it a major research hotspot in the field. Among them, the rational development of low-cost catalysts for the efficient and highly selective synthesis of ammonia remains the core key to this technology. In this study, waste corn stalks were used as a carbon source and phytic acid as a phosphorus source to successfully prepare a biomass carbon-supported iron-nickel bimetallic phosphide catalyst (NiFeP/PBC) using a one-step calcination method. The catalyst exhibited excellent electrocatalytic nitrite reduction reaction (eNO₂RR) performance for ammonia synthesis, at a voltage of －0.2 V (vs. RHE), the faradaic efficiency reaches as high as 95.9%, the ammonia yield achieves 304.9 μmol•h⁻¹•cm⁻², and the catalyst exhibits excellent stability (over 15 cycling tests). Electrochemical in-situ infrared studies indicated that key intermediates such as NO, NH₂, and NH₃ were generated during the reaction, and active hydrogen (*H) played an important role in the reduction process. Both X-ray diffraction and scanning electron microscope characterizations demonstrated that the morphology of the catalyst did not change significantly after the reaction, and ¹⁵N isotope labeling experiments confirmed that all nitrogen in the solution originated from the electrolyte rather than the environment. Meanwhile, the tests revealed that the catalyst possessed a larger electrochemical active surface area and more prominent ammonia production performance in the presence of a phosphorus source, confirming that the introduction of phosphorus can optimize the water dissociation process and hydrogen adsorption energy. This study offers a new strategy for waste biomass valorization and green electrochemical ammonia synthesis, with great scientific significance and application potential for developing high-efficiency, low-cost electrocatalysts and preparing carbon-supported metal materials from renewable energy production.