Oxygen-Vacancy-Induced Built-In Electric Field across MoCo Dual-Atomic Site Catalyst for Promoting Hydrogen Spillover in Hydrocracking and Hydrodesulfurization

作者：Guangxun Sun, Dongyuan Liu, Hongfu Shi, Junxi Li, Lingqing Yang, Fengyu Tian, Yuchen Cui, Chun‐Lin Wang, Feiyang Li, Ting Zhao, Houyu Zhu, Bin Liu, Yong‐Ming Chai, Yunqi Liu, Yuan Pan · 发表于：ACS Catalysis · 年份：2024 · DOI：10.1021/acscatal.3c05911 · 被引用次数：59 · 研究领域：Catalysis and Hydrodesulfurization Studies、Nanomaterials for catalytic reactions、Electrocatalysts for Energy Conversion

The design and construction of highly efficient catalytic active sites for promoting hydrogen spillover are of great significance for improving hydrocracking (HCK) and hydrodesulfurization (HDS) performance in slurry-phase hydrogenation of vacuum residue (VR) but are still challenging. Herein, we report a carbon-supported MoCo dual-atomic site catalyst (MoCo DAC/C) and propose an oxygen-vacancy-induced built-in electric field (BIEF) regulation mechanism for promoting hydrogen spillover in HCK and HDS. It was found that the coordination structure of the MoCo dual-atomic was reconstructed and formed O vacancies in situ during hydrogenation process. The formation of O vacancies not only provided macromolecular adsorption sites but also broke the electronic balance and formed a weak BIEF between the Mo and Co atoms. Meanwhile, H 2 was activated at the Mo sites to form active hydrogen species. The formation of BIEF promoted the active hydrogen spillover from Mo to Co sites by a Mo–C–Co bridging bond, thus improving the hydrogenation performance greatly. In HCK of VR, the MoCo DAC/C demonstrates remarkable catalytic hydrogenation activity with TOF T calculated for total metals up to 0.77 s –1 (two times enhancement than that of Mo single atoms (SAs)/C), the per pass conversion of VR of 76 wt %, liquid product yield of 92 wt %, and coke content of only 0.55 wt %. It also shows robust HDS performance with dibenzothiophene (DBT) conversion of 70 wt %. Density functional theory reveals...