Phase-Regulated FeSe<sub>2</sub>@(1T-2H)-MoSe<sub>2</sub> Derived from Anderson-Type Polyoxometalate as an Efficient Electrocatalyst for the Nitrogen Reduction Reaction
Xinming Wang, Mengle Yang, Carlos J. Gómez‐García, Xixian Cao, Zhongxin Jin, Huiyuan Ma, Haijun Pang, Guixin Yang
Abstract
The ambient electrolytic nitrogen reduction reaction (e-NRR) has been extensively studied as a potential alternative to the capital and energy-intensive Haber–Bosch process for ammonia production. However, the design and construction of highly effective catalysts for e-NRR are still extremely challenging. In this work, a series of phase-regulated composites FeSe 2 @(1T-2H)-MoSe 2 - X ( X represents the reaction time of 4, 6, and 8 h) were designed and synthesized by using the Anderson-type polyoxometalate as a preassembly platform, together with phase engineering. The progressive transformation from 2H-MoSe 2 to 1T-MoSe 2 can be implemented in FeSe 2 @(1T-2H)-MoSe 2 - X by inserting Fe and changing the reaction time. The electrocatalytic performances have been significantly improved thanks to the synergistic effect of FeSe 2, 2H-MoSe 2, and 1T-MoSe 2, which gives rise to a very high electron transfer capability and more active sites. In particular, composite FeSe 2 @(1T-2H)-MoSe 2 -6 h (with 69.7% of 1T-MoSe 2 and 29.3% of 2H-MoSe 2 ) exhibits an optimal NH 3 yield rate of 28.31 μg h –1 mg cat –1 and a Faradaic efficiency of 32.01%. Density functional theory calculations show that multiphasic FeSe 2 @(1T-2H)-MoSe 2 -6 h with appropriate content of 1T-MoSe 2 can significantly reduce the energy of the rate-determining step (*N 2 to *N 2 H) and inhibit the process of the hydrogen evolution reaction, thereby further increasing the production of NH 3 .