A General Strategy to Glassy M-Te (M = Ru, Rh, Ir) Porous Nanorods for Efficient Electrochemical N<sub>2</sub> Fixation.

Wang, Juan; Huang, Bolong; Ji, Yujin; Sun, Mingzi; Wu, Tong; Yin, Rongguan; Zhu, Xing; Li, Youyong et al. · Adv Mater · 2020

basic_science · Level V

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Abstract

Electrochemical conversion of nitrogen (N<sub>2</sub> ) into value-added ammonia (NH<sub>3</sub> ) is highly desirable yet formidably challenging due to the extreme inertness of the N<sub>2</sub> molecule, which makes the development of a robust electrocatalyst prerequisite. Herein, a new class of bullet-like M-Te (M = Ru, Rh, Ir) glassy porous nanorods (PNRs) is reported as excellent electrocatalysts for N<sub>2</sub> reduction reaction (NRR). The optimized IrTe<sub>4</sub> PNRs present superior activity with the highest NH<sub>3</sub> yield rate (51.1 µg h<sup>-1</sup> mg<sup>-1</sup> <sub>cat.</sub> ) and Faraday efficiency (15.3%), as well as long-term stability of up to 20 consecutive cycles, making them among the most active NRR electrocatalysts reported to date. Both the N<sub>2</sub> temperature-programmed desorption and valence band X-ray photoelectron spectroscopy data show that the strong chemical adsorption of N<sub>2</sub> is the key for enhancing the NRR and suppressing the hydrogen evolution reaction of IrTe<sub>4</sub> PNRs. Density functional theory calculations comprehensively identify that the superior adsorption strength of IrTe<sub>4</sub> adsorptions originates from the synergistic collaboration between electron-rich Ir and the highly electroactive surrounding Te atoms. The optimal adsorption of both N<sub>2</sub> and H<sub>2</sub> O in alkaline media guarantees the superior consecutive NRR process. This work opens a new avenue for designing high-performance NRR electrocatalysts based on glassy materials.