Heterogeneous Pt and MoO_<i>x</i> Co-Loaded TiO₂ Catalysts for Low-Temperature CO₂ Hydrogenation To Form CH₃OH

Abstract

Efficient conversion of CO2 into useful chemicals, exemplified by the development of methods for low-temperature hydrogenation of CO2 to form methanol (CH3OH), is a highly attractive research target. Herein, we report that Pt nanoparticles, loaded on MoOx/TiO2 as a support (Pt(3)/MoOx(30)/TiO2; Pt 3 wt %, MoO3 30 wt %), promote selective hydrogenation of CO2 to produce CH3OH in 73% yield under mild conditions (T = 150 °C; t = 48 h; pCO2 = 1 MPa; pH2 = 5 MPa). It is significant that the observed yield is almost the equilibrium yield of CH3OH expected under the current reaction conditions. In terms of both the yield and selectivity for CH3OH production, the performance of Pt(3)/MoOx(30)/TiO2 is better than that of other metal catalysts supported on MoOx(30)/TiO2 and of Pt catalysts on other supports. Moreover, the results of an investigation of the reaction mechanism using in situ X-ray absorption fine structure (XAFS) suggest that reduced MoOx species are responsible for the progress of this efficient reaction.