Optimization of the Zr Content in the CuO-ZnO-ZrO2/SAPO-11 Catalyst for the Selective Hydrogenation of CO+CO2 Mixtures in the Direct Synthesis of Dimethyl Ether

Abstract

Zr incorporation in the CuO-ZnO catalyst for methanol synthesis from CO+CO2 mixtures, for its later use in the bifunctional catalyst conformation for dimethyl ether (DME) direct synthesis, has been studied. Different Cu/Zn/Zr ratio catalysts were prepared, via coprecipitation method, and characterized regarding to physical, chemical, structural, and metallic properties. Specific Cu surface area and dispersion are responsible for boosting the activity of CuO-ZnO based catalysts, which increases when incorporating ZrO2. Based on the kinetic behavior (COx conversion and methanol yield and selectivity) and stability in the methanol synthesis, CZZr1 (Cu:Zn:Zr = 2:1:1) was selected as the most suitable metallic function, with 8.14% of COx conversion and methanol selectivity over 98%. A bifunctional catalyst was prepared by physical mixture of CZZr1 with SAPO-11. The bifunctional catalyst activity was tested on the DME direct synthesis, showing a good performance providing a high DME yield and selectivity, with ...