Unveiling the Pivotal Role of dx2-y2  Electronic States in Nickel-based Hydroxide Electrocatalysts for Methanol Oxidation

Angew Chem Int Ed Engl. 2024 Apr 15:e202404730. doi: 10.1002/anie.202404730. Online ahead of print.ABSTRACTThe anodic methanol oxidation reaction (MOR) plays a crucial role in coupling with the cathodic hydrogen evolution reaction (HER) and enables the sustainable production of the high-valued formate. Nickel-based hydroxide (Ni(OH)2) as MOR electrocatalyst has attracted enormous attention. However, the key factor determining the intrinsic catalytic activity remains unknown, which significantly hinders the further development of Ni(OH)2 electrocatalyst. Here, we found that the dx2-y2 electronic state within antibonding bands plays a decisive role in the whole MOR process. The onset potential depends on the deprotonation ability (Ni2+ to Ni3+), which was closely related to the band center of dx2-y2 orbital. The closer of dx2-y2 orbital to the Fermi level showed the stronger the deprotonation ability. Meanwhile, in the high potential region, the broadening of dx2-y2 orbital would facilitate the electron transfer from methanol to catalysts (Ni3+ to Ni2+), further enhancing the catalytic properties. Our work for the first time clarifies the intrinsic relationship between dx2-y2 electronic state and the MOR activities, which adds a new layer of understanding to the methanol electrooxidation research scene.PMID:38618864 | DOI:10.1002/anie.202404730

Source: Angewandte Chemie - April 15, 2024 Category: Chemistry Authors: Junhua Li Chao Wu Zhen Wang Haoyan Meng Qi Zhang Ying Tang Anqi Zou Yiming Zhang Haoyin Zhong Shibo Xi Junmin Xue Xiaopeng Wang Jiagang Wu Source Type: research