Boosting CO hydrogenation towards C2+ hydrocarbons over interfacial TiO2−x/Ni catalysts
Ming Xu, Xuetao Qin, Yao Xu, Xiaochen Zhang, Lirong Zheng, Jin‐Xun Liu, Meng Wang, Xi Liu, Ding Ma
Abstract
Abstract Considerable attention has been drawn to tune the geometric and electronic structure of interfacial catalysts via modulating strong metal-support interactions (SMSI). Herein, we report the construction of a series of TiO 2− x /Ni catalysts, where disordered TiO 2− x overlayers immobilized onto the surface of Ni nanoparticles (~20 nm) are successfully engineered with SMSI effect. The optimal TiO 2− x /Ni catalyst shows a CO conversion of ~19.8% in Fischer – Tropsch synthesis (FTS) process under atmospheric pressure at 220 °C. More importantly, ~64.6% of the product is C 2+ paraffins, which is in sharp contrast to the result of the conventional Ni catalyst with the main product being methane. A combination study of advanced electron microscopy, multiple in-situ spectroscopic characterizations, and density functional theory calculations indicates the presence of Ni δ− /TiO 2− x interfacial sites, which could bind carbon atom strongly, inhibit methane formation and facilitate the C-C chain propagation, lead to the production of C 2+ hydrocarbon on Ni surface.