Abstract

The direct hydrogenation of CO₂ into dimethyl-ether (DME) has been studied in presence of zeolite-based hybrid catalysts, prepared through gel-oxalate coprecipitation of copper, zinc and zirconium precursors (in an atomic ratio of 60 : 30 : 10 respectively) in a solution containing different home-made zeolites (i.e., Sil-1, MFI, Y, FER, BEA, MOR), for a final CuZnZr/zeolite weight composition of 1:1. All the samples were properly characterized with different techniques for determining the textural, structural and morphological nature of the catalytic surface. N₂ physisorption highlighted a variation both in the specific surface area and in the pore size distribution from the parent zeolites to the hybrid catalyst. TEM analyses disclosed how the pre-formed zeolite architecture affects the distribution of the oxides on the surface, significantly controlling not only the activity-selectivity pattern under the adopted experimental conditions (T_R, 200–260°C; P_R, 30 bar, GHSV: 8.800 NL/kg_cat/h), but also the catalyst stability during time on-stream.

中文翻译：

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促进基于沸石的杂化催化剂将CO 2直接转化为DME

摘要

在沸石-杂化催化剂的存在下，已经研究了将CO ₂直接加氢成二甲醚（DME），该催化剂是通过草酸铜共沉淀铜，锌和锆前体（原子比分别为60:30:10）制备的）溶液中含有不同的自制沸石（即Sil-1，MFI，Y，FER，BEA，MOR），最终CuZnZr /沸石的重量比为1：1。用不同的技术对所有样品进行适当的表征，以确定催化表面的质地，结构和形态性质。N ₂物理吸附突出显示了从母体沸石到杂化催化剂的比表面积和孔径分布的变化。TEM分析揭示了预制沸石的结构如何影响表面氧化物的分布，不仅显着控制了所采用的实验条件（T _R，200–260°C；P _R，30 bar， GHSV：8.800 N L / kg _cat / h），但在运行期间催化剂也稳定。