Long-term electrocatalytic N 2 fixation by MOF-derived Y-stabilized ZrO 2 : insight into the deactivation mechanism

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 8; no. 11; pp. 5647 - 5654
• Main Authors: Luo, Shijian, Li, Xiaoman, Wang, Mingyuan, Zhang, Xu, Gao, Wanguo, Su, Senda, Liu, Guiwu, Luo, Min
• Format: Journal Article
• Language: English
• Published: 17.03.2020
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/D0TA01154A

Industrially, NH 3 synthesis is largely dependent on the Haber–Bosch method which consumes a lot of energy and emits huge amounts of CO 2 . Recently, the electrochemical N 2 reduction reaction (NRR) has been recognized as a promising method to achieve clean and sustainable NH 3 production, thus highly efficient and durable catalysts are urgently desired. In this paper, we report a MOF-derived carbon/Y-stabilized ZrO 2 nanocomposite (C@YSZ) that works as an efficient electrocatalyst for NRR in 0.1 M Na 2 SO 4 . It achieves a large NH 3 production of 24.6 μg h −1 mg cat. −1 and a high faradaic efficiency of 8.2% at −0.5 V vs. the reversible hydrogen electrode. The experimental results demonstrate that the surface oxygen vacancies are the main catalytic sites for NRR. Introducing Y 3+ into the ZrO 2 lattice has a significant effect to increase and stabilize the O-vacancies. Meanwhile, this catalyst displays remarkable stability and durability for NRR, showing negligible change after 7 days reaction, which is better than most reported NRR electrocatalysts. Moreover, an in situ electrochemical quartz-crystal microbalance (EQCM) was applied in the NRR field for the first time and was successfully combined with density functional theory (DFT) calculations to reveal the deactivation mechanism.