Boosting CO hydrogenation towards C 2+ hydrocarbons over interfacial TiO 2-x /Ni catalysts.

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.