Optimizing Electrocatalytic Nitrogen Reduction via Interfacial Electric Field Modulation: Elevating d-Band Center in WS2 -WO3 for Enhanced Intermediate Adsorption.

ABSTRACT

Electrocatalytic nitrogen reduction reaction (ENRR) has emerged as a promising approach to synthesizing green ammonia under ambient conditions. Tungsten (W) is one of the most effective ENRR catalysts. In this reaction, the protonation of intermediates is the rate-determining step (RDS). Enhancing the adsorption of intermediates is crucial to increase the protonation of intermediates, which can lead to improved catalytic performance. Herein, we constructed a strong interfacial electric field in WS2 -WO3 to elevate the d-band center of W, thereby strengthening the adsorption of intermediates. Experimental results demonstrated that this approach led to a significantly improved ENRR performance. Specifically, WS2 -WO3 exhibited a high NH3 yield of 62.38 µg h-1 mgcat -1 and a promoted faraday efficiency (FE) of 24.24 %. Furthermore, in situ characterizations and theoretical calculations showed that the strong interfacial electric field in WS2 -WO3 upshifted the d-band center of W towards the Fermi level, leading to enhanced adsorption of -NH2 and -NH intermediates on the catalyst surface. This resulted in a significantly promoted reaction rate of the RDS. Overall, our study offers new insights into the relationship between interfacial electric field and d-band center and provides a promising strategy to enhance the intermediates adsorption during the ENRR process.