Electrochemical ammonia synthesis via nitrogen reduction reaction on 1T/2H mixed-phase MoSSe catalyst: Theoretical and experimental studies

Abstract

Electrocatalytic nitrogen reduction (NRR) is regarded as an energy-efficient technology to produce NH3. Nevertheless, achieving high NH3 yield and Faradaic efficiency (FE) under ambient conditions remains a great challenge. Herein, 1T/2H mixed-phase MoS0·5Se1.5 (named 1T/2H MoSSe) nanoflower, as an efficient non-noble metal NRR electrocatalyst, was synthesized by the one-step solvothermal method. 1T/2H MoSSe realizes an excellent NH3 yield of 32.32 μg h−1 mgcat.−1 at −0.45 V vs. RHE and an outstanding FE of 12.66% at −0.40 V vs. RHE in 0.1 M HCl, which are better than pure MoS2 (NH3 yield: 15.16 μg h−1 mgcat.−1, FE: 0.35%) and MoSe2 (NH3 yield: 26.42 μg h−1 mgcat.−1, FE: 2.75%). Density functional theory (DFT) calculations exhibit that MoSSe catalyst is structurally favorable to the potential-determining step (PDS, *NH–NH2 → *NH2–NH2) and thus shows increased NRR activity and selectivity. A promising tactic for the rational design of economical, efficient, and durable NRR electrocatalysts is proposed in this work.