Influence of Rare Earth Promoters on Cu-Based Catalysts in the New Low-Temperature Methanol Synthesis Reaction

摘要

The reactions of the methanol synthesis were conducted from the CO/CO2/H2 on the Cu-based catalysts using different solvent at 443 K and 3.0 MPa.The alcohol solvent had the activity,and other solvent such as the cyclohexane or the 1-octene had not activity in the new lowtemperature methanol synthesis reaction.The activity order of the different alcohol was 2-propanol ＞ 2-butanol ＞ ethanol in the new low-temperature methanol synthesis reaction.The activity of the Cu-based catalyst with ZnO as carrier was higher than that of the catalyst with Y2O3,La2O3,Al2O3,or MgO as carrier separately in the new lowtemperature methanol synthesis reaction.The addition of the Y2O3,the CeO2 or La2O3 to the Cu/ZnO catalysts improved the copper species dispersion,so that it was easier for the reduction of the Cu/Y2O3-ZnO,the Cu/CeO2-ZnO and the Cu/La2O3-ZnO catalysts than that of the Cu/ZnO catalyst according to the TPR analysis.The variation trend of the copper surface area (23.2 m2/g ＜ 23.9 m2/g ＜ 24.8 m2/g ＜ 25.9 m2/g) was consistent with those of the total carbon conversion,the selectivity and the productivity of the methanol for the Cu/ZnO,the Cu/Y2O3-ZnO,the Cu/CeO2- ZnO and the Cu/La2O3-ZnO catalysts in the new lowtemperature methanol synthesis reaction.The activity of the Cu/Y2O3-ZnO,the Cu/CeO2-ZnO and the Cu/La2O3-ZnO was higher than that of the Cu/ZnO catalyst,and the activity of the Cu/La2O3-ZnO catalyst was the highest in the new low-temperature methanol synthesis reaction in this study.