MoS2 Polymorphic Engineering Enhances Selectivity in the Electrochemical Reduction of Nitrogen to Ammonia

• Published in: ACS energy letters Vol. 4; no. 2; pp. 430 - 435
• Main Authors: Suryanto, Bryan H. R, Wang, Dabin, Azofra, Luis Miguel, Harb, Moussab, Cavallo, Luigi, Jalili, Rouhollah, Mitchell, David R. G, Chatti, Manjunath, MacFarlane, Douglas R
• Format: Journal Article
• Language: English
• Published: American Chemical Society 08.02.2019
• ISSN: 2380-8195; 2380-8195
• DOI: 10.1021/acsenergylett.8b02257

The electrochemical N2 reduction reaction (NRR) offers a direct pathway to produce NH3 from renewable energy. However, aqueous NRR suffers from both low Faradaic efficiency (FE) and low yield rate. The main reason is the more favored H+ reduction to H2 in aqueous electrolytes. Here we demonstrate a highly selective Ru/MoS2 NRR catalyst on which the MoS2 polymorphs can be controlled to suppress H+ reduction. A NRR FE as high as 17.6% and NH3 yield rate of 1.14 × 10–10 mol cm–2 s–1 are demonstrated at 50 °C. Theoretical evidence supports a hypothesis that the high NRR activity originates from the synergistic interplay between the Ru clusters as N2 binding sites and nearby isolated S-vacancies on the 2H-MoS2 as centers for hydrogenation; this supports formation of NH3 at the Ru/2H-MoS2 interface.