氨不僅能作為化學原料和植物肥料，還是一種可提供高能量密度的無碳能源載體。現今，許多研究致力於尋找可再生資源的氨合成技術。其中，在常溫常壓環境下，通過電催化氮還原技術合成氨，是目前工業採用的高能源消耗及較低延續性的哈柏製氨法的替代方法。
本研究使用鐵和鈷共摻雜二硫化鉬生長在碳布上作為電催化劑，實現了在弱酸性電解液中的電催化氮還原，實驗結果顯示，相較於純二硫化鉬，適當摻雜濃度的鐵鈷共摻雜二硫化鉬，在各個電壓下的氨產率皆大幅度上升，在電位-0.55 V，達到3.27 µg h−1 cm−2之氨產率，超過純二硫化鉬、鐵摻雜二硫化鉬及鈷摻雜二硫化鉬的氨產率，分別為191%、176%及116%；法拉第效率也有明顯提升，在電位-0.35 V，達到6.28%之法拉第效率，分別為純二硫化鉬、鐵摻雜二硫化鉬及鈷摻雜二硫化鉬的217%、186%及132%之法拉第效率，顯示提高鐵摻雜濃度並加入少量的鈷摻雜，可以提升材料的催化活性。而增強的電催化產氨性能可歸因於鐵和鈷摻雜原子的協同作用，不僅引入活性位點，增加材料本質活性，還促進了材料的電荷轉移。
此外，密度泛函理論計算結果顯示鐵鈷共摻雜二硫化鉬的反應最佳路徑為末端途徑，且其電位決定步驟之自由能障僅0.54 eV，比純二硫化鉬之自由能障1.13 eV低許多，表示鐵鈷共摻雜二硫化鉬能有更好的催化活性；而巴德電荷分析結果顯示鐵鈷共摻雜可促進電荷轉移，減弱鉬原子對反應中間產物之吸附能力，使氮還原反應優先發生在作為活化位置的鐵原子，綜合上述，適量的鐵鈷共摻雜濃度能使二硫化鉬的催化活性提升。

Ammonia is not only essential to life as a chemical feedstock and fertilizers but also considered as a carbon-free energy carrier that offers high energy density. Nowadays, many efforts have been devoted to searching renewable-energy-based NH3 synthesis techniques. In particular, NH3 synthesis by the electrocatalytic N2 reduction reaction (NRR) under ambient conditions is a promising alternative way to the currently employed energy-intensive and non-sustainable Haber-Bosch process.
In this thesis, we demonstrated that the NRR could be achieved by using Fe and Co co-doping MoS2 nanosheets supported on carbon cloth that served as an electrocatalyst. At optimal doping concentration, Fe and Co co-doping MoS2 exhibited an ammonia yield rate of 3.27 µg h−1 cm−2 at −0.55 V versus RHE, which reached higher performance than that of undoped MoS2, Fe-doped MoS2 and Co-doped MoS2 samples by 191%, 176% and 116%, respectively, and a FE of 6.28% at -0.35 V versus RHE, exceeding that of undoped MoS2, Fe-doped MoS2 and Co-doped MoS2 samples by 217%, 186% and 132%, respectively. The enhanced NRR performance can be attributed to the synergistic effects of Fe and Co dopants which induce the active sites, increase intrinsic activity, and promote the charge transfer.
Additionally, density functional theory calculations reveal that the preferred reaction pathway of FeCo-MoS2 electrocatalyst is distal pathway and its potential-determining step has a lower energy barrier（0.54 eV）than that of undoped MoS2（1.13 eV）which indicates FeCo-MoS2 possesses better electrocatalytic activity. Besides, the Bader analysis shows that Fe and Co dopants enable electron transfer and thus optimize the free energies of reaction intermediates. Therefore, Fe and Co were determined to be effective dopants for boosting the NRR activity of MoS2 catalyst.

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