Preparation of Cu/ZnO/Al2O3 catalyst under microwave irradiation for slurry methanol synthesis

Abstract

Cu/ZnO/Al 2 O 3 catalysts with Cu/Zn/Al ratios of 6/3/1 were precipitated and aged by conventional and microwave heating methods and tested in the slurry phase reactor for methanol synthesis. The effect of technological condition of precipitation and aging process under microwave irradiation on the catalytic performance was investigated to optimize the preparing condition of Cu/ ZnO/Al 2 O 3 catalyst. The results showed that the microwave irradiation during precipitation process could improve the activity of the catalyst, but had little effect on the stability. While the microwave irradiation during aging process has a great benefit to both the activity and stability of the catalyst, the catalyst aged at 80°C for 1 h under microwave irradiation possessed higher methanol space time yield (STY) and more stable catalytic activity. The activity and stability of the catalyst was further enhanced when microwave irradiation was used in both precipitation and aging processes; the optimized condition for the catalyst precursor preparation was precipitation at 60°C and aging at 80°C under microwave irradiation.

A study on the structure and catalytic performance of ZnxCu1−xAl2O4 catalysts synthesized by the solution combustion method for the esterification reaction

“…Acid sites of a catalyst are known to have an important role in the esterification reaction. According to the results of XRD analysis, the 0.4ZCA catalyst showed broad peaks with low intensity compared to the other samples, confirming good dispersion of copper and zinc oxides on alumina and an intense interaction, resulting in higher catalytic activity [39]. The 0.4ZCA catalyst showed maximum catalytic activity with relatively low water solubility.…”

Challenges in the Greener Production of Formates/Formic Acid, Methanol, and DME by Heterogeneously Catalyzed CO2Hydrogenation Processes

“…According to the study, the best catalytic performance was obtained when the precursors were precipitated at the pH of 6 to 8 at 70 °C followed by an aging time of 20–60 min and a final calcination at 300 °C. Fan et al 143 reported the assistance of microwave (MW) irradiation in the coprecipitation and in the aging steps for the synthesis of Cu–ZnO–Al 2 O 3 catalysts. Their results on one hand showed that MW irradiation at the coprecipitation step could improve the activity of the catalyst, but not the stability.…”

Parameters Optimization Based on the Taguchi Robust Design for the Synthesis of CuO–ZnO Nanocomposite Using the Surfactant-Assisted Coprecipitation Method

“…Also, the effect of microwave irradiation on the properties of CuO-ZnO catalyst prepared by coprecipitation method was studied. [29] It is well known that the properties of CuO-ZnO catalyst obtained by coprecipitation method are affected by various parameters. The interrelationships and interactions between the all parameters are complex, and the comprehensive analysis of this system to optimize the factors requires a time and laborconsuming work.…”

“…These factors are calcination temperature (A), capping agent (B), drying temperature (C), precipitating agent (D), molarities of Cu and Zn ions (E), microwave power (F), and pH at the end of precipitation (G). In this study, experimental design was performed according to the L 8 (2 7 ) Taguchi orthogonal design [29,30] for optimizing the procedure to synthesis CuO-ZnO nanocomposite with high specific surface area. The seven factors and their levels are summarized in Table 1.…”