Core@Shell Heterostructured NiMoP<i><sub>x</sub></i>@Ni<sub>5</sub>P<sub>4</sub> Nanorod Arrays Promoting Direct Electro‐Oxidation of Methanol and Hydrogen Evolution under Industry Conditions
Botao Zhu, Jie Xiong, Shuo Wu, Kaixuan You, Bin Sun, Yixiang Liu, Muzi Chen, Peng Jin, Lai Feng
Abstract
Abstract Methanol‐electrooxidation‐reaction (MOR) to value‐added formate is a promising alternative to water oxidation for cost‐efficient hydrogen production. It is generally proposed that the MOR kinetics on Ni‐based catalysts are highly limited by the transition rate of Ni(OH) 2 /NiOOH. Yet, how to define the catalyst following the direct pathway without Ni 2+ /Ni 3+ transition remains challenging. Herein, a core@shell heterostructured NiMoP x @Ni 5 P 4 catalyst is developed to selectively promote the MOR at a large current density (> 500 mA cm −2 ). A series of operando spectroscopic studies reveal negligible formation of NiOOH with 1.0 m methanol in a wide potential range, where MOR is predominant. Theoretical calculations demonstrate that the Ni‐P site of NiMoP x @Ni 5 P 4 favors the adsorption of * CH 3 OH over * OH while the heterostructure contributes to the significantly reduced energy barrier of * OCH 3 → * OCH 2 , hence promoting the MOR along a direct pathway without the formation of NiOOH. Moreover, further study suggests that the catalyst also performs well toward cathodic hydrogen evolution reaction (HER). As a result, an electrode pair of NiMoP x @Ni 5 P 4 //NiMoP x @Ni 5 P 4 is employed to enable concurrent MOR/HER electrolysis at 1.81 V to yield formate/H 2 with FEs of ca. 90/100% and long‐term (100‐h) sustainability at 500 mA cm −2 under the industrial conditions (6.0 m KOH, 65 °C).