Materializing efficient methanol oxidation via electron delocalization in nickel hydroxide nanoribbon
Xiaopeng Wang, Shibo Xi, Wee Siang Vincent Lee, Pengru Huang, Peng Cui, Lei Zhao, Weichang Hao, Xinsheng Zhao, Zhen‐Bo Wang, Haijun Wu, Hao Wang, Caozheng Diao, Armando Borgna, Yonghua Du, Zhi Gen Yu, Stephen J. Pennycook, Junmin Xue
Abstract
Abstract Achieving a functional and durable non-platinum group metal-based methanol oxidation catalyst is critical for a cost-effective direct methanol fuel cell. While Ni(OH) 2 has been widely studied as methanol oxidation catalyst, the initial process of oxidizing Ni(OH) 2 to NiOOH requires a high potential of 1.35 V vs. RHE. Such potential would be impractical since the theoretical potential of the cathodic oxygen reduction reaction is at 1.23 V. Here we show that a four-coordinated nickel atom is able to form charge-transfer orbitals through delocalization of electrons near the Fermi energy level. As such, our previously reported periodically arranged four-six-coordinated nickel hydroxide nanoribbon structure (NR-Ni(OH) 2 ) is able to show remarkable methanol oxidation activity with an onset potential of 0.55 V vs. RHE and suggests the operability in direct methanol fuel cell configuration. Thus, this strategy offers a gateway towards the development of high performance and durable non-platinum direct methanol fuel cell.