A general strategy to glassy M-Te (M = Ru, Rh, Ir) porous nanorods for efficient electrochemical N2 fixation

Abstract

Electrochemical conversion of nitrogen (N2) into value-added ammonia (NH3) is highly desirable yet formidably challenging due to the extreme inertness of the N2 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 N2 reduction reaction (NRR). The optimized IrTe4 PNRs present superior activity with the highest NH3 yield rate (51.1 µg h−1 mg−1 cat.) 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 N2 temperature-programmed desorption and valence band X-ray photoelectron spectroscopy data show that the strong chemical adsorption of N2 is the key for enhancing the NRR and suppressing the hydrogen evolution reaction of IrTe4 PNRs. Density functional theory calculations comprehensively identify that the superior adsorption strength of IrTe4 adsorptions originates from the synergistic collaboration between electron-rich Ir and the highly electroactive surrounding Te atoms. The optimal adsorption of both N2 and H2O 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.