Significantly enhanced electrocatalytic N2 reduction to NH3 by surface selenization with multiple functions. Issue 39 (2nd October 2020)

• Record Type: Journal Article
• Authors: Cai, Wenwen; Han, Yi; Li, Hongdong; Qi, Wenjing; Xu, Jixiang; Wu, Xueke; Zhao, Huan; Zhang, Xinyi; Lai, Jianping; Wang, Lei
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 39(2020)
• Page Start: 20331
• Page End: 20336
• Publication Date: 2020-10-02
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0ta06991d
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Surface-selenized RuO2 /C (RuO2 -Se0.18 /C) exhibits a high NH3 yield rate (12.97 μg h −1 cm −2 ) at low overpotential. The superior NRR performance is attributed to the effects (on N2 adsorption, surface hydrogenation, N2 activation and NH3 desorption) of surface selenization. Abstract : The electrochemical N2 reduction reaction (NRR) under ambient conditions is highly attractive. However, it is still a challenge to achieve a high NH3 yield rate at low overpotential. Herein, we report RuO2 nanoparticles with different degrees of surface selenation, which show excellent NRR performance at low overpotential. The NH3 yield rate and FE of RuO2 –Se0.18 /C reach 12.97 μg h −1 cm −2 and 26.01% at −0.1 V vs. RHE, respectively, which is the highest NH3 yield rate reported at low overpotential. The RuO2 –Se0.18 /C catalyst also shows excellent stability. The related NH3 yield rate stays pretty constant after 50 h of electrolysis. The density functional theory (DFT) calculations show multiple promoted-synergism of surface selenation on the RuO2 catalyst. First, optimized surface selenization could drive the adsorption of N2 on RuO2 sites. Second, surface hydrogenation promoted by surface selenization can suppress the hydrogen evolution reaction (HER, competitive reaction), enabling high NRR performance at low potential. Third, optimizing the surface selenization on RuO2 can promote N2 activation (*N2 → *NNH). Fourth, surface selenization can promote NH3 desorption (the rate-limiting step).