Introduction of TiO2 enhancing the catalytic performance of Ti(SO4)2/SiO2 for dimethyl ether oxidation

Abstract

The introduction of a small amount of TiO₂ changes the surface properties of the SiO₂ material, which further significantly affects the dispersion state of Ti(SO₄)₂. The differences in acidity and redox caused by the distribution of Ti(SO₄)₂ are closely related to the catalyst performance for dimethyl ether (DME) oxidation. In particular, the calcination temperature could adjust the surface hydroxyl content of TiO₂/SiO₂, which determines the dispersion of Ti(SO₄)₂ components, resulting in distinct acid sites and Ti valence. The most number of weak acid sites and the highest proportion of Ti³⁺/Ti⁴⁺ in the Ti(SO₄)₂/TS-400 °C catalyst remarkably promote the formation of dimethoxymethane (DMM) from 14.4% to 82.6%, compared to the Ti(SO₄)₂/SiO₂ catalyst.