Metastable Hexagonal Phase SnO<sub>2</sub> Nanoribbons with Active Edge Sites for Efficient Hydrogen Peroxide Electrosynthesis in Neutral Media
Yi Zhang, Mengwen Wang, Wenxiang Zhu, Miaomiao Fang, Mengjie Ma, Fan Liao, Hao Yang, Tao Cheng, Chih‐Wen Pao, Yu‐Chung Chang, Zhiwei Hu, Qi Shao, Mingwang Shao, Zhenhui Kang
Abstract
Abstract Electrochemical two‐electron oxygen reduction reaction (2 e − ORR) to produce hydrogen peroxide (H 2 O 2 ) is a promising alternative to the energetically intensive anthraquinone process. However, there remain challenges in designing 2 e − ORR catalysts that meet the application criteria. Here, we successfully adopt a microwave‐assisted mechanochemical‐thermal approach to synthesize hexagonal phase SnO 2 (h‐SnO 2 ) nanoribbons with largely exposed edge structures. In 0.1 M Na 2 SO 4 electrolyte, the h‐SnO 2 catalysts achieve the excellent H 2 O 2 selectivity of 99.99 %. Moreover, when employed as the catalyst in flow cell devices, they exhibit a high yield of 3885.26 mmol g −1 h −1 . The enhanced catalytic performance is attributed to the special crystal structure and morphology, resulting in abundantly exposed edge active sites to convert O 2 to H 2 O 2 , which is confirmed by density functional theory calculations.