Identifying the Activity Origin of a Single-Atom Au<sub>1</sub>/Nb<sub>2</sub>O<sub>5</sub> Catalyst for Hydrodeoxygenation of Methylcatechol: A Stable Substitutional Au<sup>+</sup> Site
Jie Xia, Lin Dong, Xiaohui Liu, Roman Chernikov, Mohsen Shakouri, Yongfeng Hu, Yong Guo, Jianjian Wang, Kepeng Song, P. Hu, Yanqin Wang, Haifeng Wang
Abstract
Developing effective and stable single-atom catalysts (SACs) is a significant but challenging task, which requires the identification of single-atom metal sites and their configurations. Herein, we report a single-atom Au 1 /Nb 2 O 5 catalyst for the hydrodeoxygenation of methylcatechol, a lignin model compound, which maintains stability in five consecutive conversions. Combined with the density functional theory (DFT) calculations, the Au + located at the Nb lattice site with two concomitant oxygen vacancies (Au@Nb v –2O v ) is identified as the thermodynamically favorable Au single-atom species and dominates the activity for molecular H 2 dissociation via a heterolytic mechanism. Moreover, the presence of oxygen vacancies in Au@Nb v –2O v facilitates the adsorption of methylcatechol, resulting in efficient cleavage of C–O bonds. Consequently, we design a catalyst with more Au + sites, which exhibits enhanced catalytic activity. This work systematically elucidates the structure–activity relationship and provides a promising strategy to optimize SACs for the hydrodeoxygenation reaction.