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A series of Cu-ZnO-ZrO2 (CCZ) catalysts were prepared by the solvothermal method with different solvothermal times (1 h, 3 h, 6 h, and 12 h). The physicochemical properties of these catalysts and the catalytic performance for CO2 hydrogenation to methanol were studied. The highest methanol yield was achieved when the solvothermal time was 6 h (CCZ-6). Furthermore, we found that the copper surface area (SCu) increases and then decreases with an increase in the solvothermal time and that there is a strong correlation between the methanol yield and the SCu. This research highlights the crucial influence of the solvothermal time on the structure and catalytic behavior of Cu-ZnO-ZrO2 catalysts, providing a valuable reference for the development of efficient catalysts. [ABSTRACT FROM AUTHOR]

A series of CuO-ZnO–ZrO2 (CZZ) catalysts were synthesized via a solvothermal method. The effects of four saturated monohydric alcohols (methanol, ethanol, n-propanol, and n-butanol) as solvents on the physicochemical properties and catalytic performance for the direct synthesis of methanol from CO2 hydrogenation of the prepared catalysts were investigated. N2 physical adsorption, X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy mapping, reactive N2O adsorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction by H2 (H2-TPR), and temperature programmed desorption (H2-TPD, CO2-TPD) techniques were used to characterize the catalysts. The results indicate that the catalyst prepared with methanol as solvent (CZZ-M) has the smallest Cu crystallites and the largest metallic Cu surface area, thus exhibiting the highest methanol yield of 7.4% at 240 °C, 3.0 MPa, H2:CO2 of 3 (v/v), and GHSV of 2400 mL/(gcat·h). [ABSTRACT FROM AUTHOR]

• CuO-ZnO-ZrO 2 catalyst was prepared by a facile solvothermal route. • Effect of solvothermal temperature on performance of the catalyst was investigated. • The catalyst prepared at 180 °C exhibited the highest methanol yield. • The activity of the catalyst was closely related to capacity for H 2 adsorption. Solvothermal preparation of CuO-ZnO-ZrO 2 (CZZ) was realized using ethylene glycol as a solvent. The effects of solvothermal temperature (140–200 °C) on the properties of catalysts and catalytic performance in CO 2 hydrogenation were studied. ICP-OES, N 2 sorption, XRD, SEM-EDX, reactive N 2 O adsorption, XPS, H 2 -TPR, H 2 -TPD, and CO 2 -TPD were used as characterization tools. The data indicate that the CZZ-180 catalyst prepared at a solvothermal temperature of 180 °C has the smallest Cu crystallites and the largest surface area of Cu0, thus exhibiting the highest methanol yield. The effects of reaction temperature, pressure, and space velocity were also investigated. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, a series of Cu–Ce 1-x Zr x O 2 (x = 0, 0.2, 0.5, 0.8, 1) catalysts were prepared by an eco-friendly and facile solid-phase grinding method. The effect of different Ce/Zr molar ratios on the performance of Cu–Ce 1-x Zr x O 2 catalysts for CO 2 hydrogenation to methanol was investigated. The results showed that the Cu–Ce 0.5 Zr 0·5 O 2 catalyst had the best catalytic performance, with CO 2 conversion of 15.2 % and methanol yield of 7.5 % at GHSV = 3600 mL/(g cat ·h)); when GHSV was increased to 20,000 mL/(g cat ·h), the space-time yield of methanol reached 270.8 g CH3OH /(kg cat ·h). X-ray diffraction (XRD), scanning electron microscope (SEM), N 2 adsorption-desorption, N 2 O chemisorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction by H 2 (H 2 -TPR), and temperature programmed desorption (H 2 -TPD, CO 2 -TPD) techniques were used to characterize the catalysts, and the higher reactivity of Cu–Ce 0.5 Zr 0·5 O 2 can be attributed to more Cu0 species, defect oxygen and basic sites. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) results revealed that the hydrogenation of CO 2 to methanol occurred through the formate intermediate pathway. This work proposed an eco-friendly and facile method for the preparation of high-performance Cu-based catalysts and the systematic study provided a deep insight for the development of high-performance Cu-based catalysts for methanol synthesis from CO 2 hydrogenation. [ABSTRACT FROM AUTHOR]

Abstract: A series of Cu/ZrO2 catalysts with various La loadings for methanol synthesis from CO2 hydrogenation were prepared by a urea–nitrate combustion method. The catalysts were characterized with N2 adsorption, XRD, reactive N2O adsorption, XPS, TPR, H2-TPD and CO2-TPD techniques, and tested for methanol synthesis from CO2 hydrogenation. With increasing La loading, the Cu surface area increases first and then decreases, whereas the amount of basic site over catalysts increases continuously. The results of catalytic test reveal that a linear relationship exists between the conversion of CO2 and the Cu surface area. Moreover, it is found for the first time that the selectivity to methanol is related to the distribution of basic site on the catalyst surface. The presence of La favors the production of methanol, and the optimum catalytic activity is obtained when the amount of La doping is 5% of the total amount of Cu2+ and Zr4+. [Copyright &y& Elsevier]

Abstract: Cu/ZnO/ZrO2 catalysts were prepared by a route of solid-state reaction and tested for the synthesis of methanol from CO2 hydrogenation. The effects of calcination temperature on the physicochemical properties of as-prepared catalysts were investigated by N2 adsorption, XRD, TEM, N2O titration and H2-TPR techniques. The results show that the dispersion of copper species decreases with the increase in calcination temperature. Meanwhile, the phase transformation of zirconia from tetragonal to monoclinic was observed. The highest activity was achieved over the catalyst calcined at 400°C. This method is a promising alternative for the preparation of highly efficient Cu/ZnO/ZrO2 catalysts. [Copyright &y& Elsevier]

Abstract: A series of CuO–ZnO–ZrO2 (CZZ) catalysts were synthesized by a glycine–nitrate combustion method and characterized by XRD, BET, N2O chemisorption, SEM and TPR techniques. The results show that the physicochemical properties of the catalysts are strongly influenced by the fuel content used in the combustion process. The dispersion of CuO exhibits an inverse-volcano variation trend with an increase in the glycine amount from 50% to 150% of the stoichiometry. The relationship between physiochemical properties and the fuel content is discussed in detail in terms of combustion temperature. The catalytic performance for the synthesis of methanol from CO2 hydrogenation was examined. The CZZ catalyst exhibits an optimum catalytic activity when 50% of stoichiometric amount of glycine was used. The turnover frequency has been calculated for various CZZ catalysts, and it reveals that the catalytic activities depend not only on the surface area of metallic copper but also on the phase state of ZrO2. [Copyright &y& Elsevier]

Abstract: Various CuO–ZnO–ZrO2 (CZZ) catalysts have been synthesized by urea–nitrate combustion method and their performances for methanol synthesis from CO2 hydrogenation have been investigated. The effects of urea/nitrate ratio on physicochemical and catalytic properties were studied by XRD, BET, H2-TPR and reactive N2O adsorption techniques. The results show that when 50% of stoichiometric amount of urea was used, the CZZ catalyst exhibited an optimum catalytic behavior. The combustion method was found to be a simple, fast and valuable route for the preparation of CZZ catalyst for methanol synthesis from CO2 hydrogenation. [Copyright &y& Elsevier]