Efficient and Stable Production of Long-Chain Hydrocarbons over Hydrophobic Carbon-Encapsulated TiO2-Supported Ru Catalyst in Fischer–Tropsch Synthesis

Abstract

The sintering of metal catalysts caused by Ostwald ripening (OR) and particle migration and coalescence (PMC) is one of the major challenges in heterogeneous catalysis. Here, we develop an efficient Ru catalyst supported on hydrophobic carbon-encapsulated TiO₂ for Fischer–Tropsch synthesis (FTS). Combining comprehensive characterizations, we discover that hydrophobic carbon layers predominantly obstruct OR, and appropriate metal–support interactions avoid PMC. The dual effects collectively prevent the aggregation and sintering of diminutive Ru nanoparticles (NPs) during the FTS process and induce robust catalytic performance. Moreover, this unique structure exposes more Ru sites to promote CO hydrogenation and diminishes Ru-TiO₂ interfaces to adsorb more *CO and fewer *H species, which facilitates the production of longer-chain hydrocarbons. Consequently, at 220 °C, our catalyst exhibits a superior turnover frequency (TOF) of 0.189 s^–1 and a Ru time yield of 2.67 mol_CO g_Ru^–1 h^–1, surpassing those of the reported Ru-based catalysts. Simultaneously, the catalyst shows a C₅₊ selectivity of 85.3% and is particularly effective in producing C₁₅₊ (soft paraffin), with a selectivity of 57.3%. Our catalyst design strategy holds promise for efficient catalytic processes in various industrial applications.