| 초록 |
Electrochemical reactions involving multiple steps, such as nitrogen reduction reaction (NRR), often suffer from low catalytic efficiency due to competition with other simple reactions. Hence, developing an electrocatalyst that can promote the selective activation of such a multistep reaction is vital. Here, we propose a highly selective electrocatalyst for NRR comprising molybdenum disulfide (MoS2) with the iron (Fe) confined in van der Waals (vdW) gaps, which is inspired by Nitrogenase capable of nitrogen fixation in atmospheric conditions. This bio-inspired structure is achieved by sequential intercalation of lithium and Fe ions followed by Fe reduction in vdW-layered MoS2, whose design is confirmed by structural analyses. We found that the metallic Fe-confined MoS2 structure offers a favorable active site for boosting selective NRR. As a result, the Faradic efficiency and yield rate of the ammonia production are obtained as high as 30.2 % and 1.2 μmol·cm-2·h-1, respectively. Such improved catalytic performances can be attributed to the change of the d-band center of MoS2 by Fe intercalation, strengthening the binding strength of nitrogen and lowering the potential barrier of NRR. Our demonstration offers new insight into designing novel catalysts to enhance selectivity and activity in complex catalytic reactions |
