基于生物模板制备二氧化碳加氢反应的Cu/ZnO催化剂

ZnO with a hierarchical pore structure was prepared using rape pollen as a biological template, and then Cu was loaded onto ZnO by the impregnation-reduction method to prepare Cu/ZnO supported catalysts (bio - CZ - 500) with different structures. It was found that the bio - CZ - 500 catalyst prepared by calcination at 500 °C showed almost unchanged activity during a 100 - h test in the CO₂ hydrogenation reaction, and the methanol selectivity was as high as 81%. In contrast, the Cu/ZnO catalyst prepared without a biological template showed a lower methanol selectivity (50%) and the catalyst deactivated rapidly within 12 h. Through characterization techniques such as transmission electron microscopy, scanning electron microscopy, nitrogen adsorption - desorption, infrared spectroscopy, X - ray diffraction, X - ray photoelectron spectroscopy, contact angle measurement, and temperature - programmed techniques, it was revealed that the bio - CZ - 500 catalyst has a hierarchical porous carbon structure, abundant Cu - ZnO active interfaces, and a relatively high water contact angle. The weak hydrophilicity of the catalyst accelerates the diffusion of the by - product water, promotes the decomposition of intermediates to produce methanol, and simultaneously inhibits the sintering deactivation of copper particles, thereby improving the selectivity of methanol and the stability of the catalyst. This work provides a new method for preparing highly efficient and stable Cu - based industrial catalysts.

采用油菜花粉作为生物模板制备了具有多层次孔结构的ZnO,再通过浸渍还原法将Cu负载于ZnO上制备了具有不同结构的Cu/ZnO负载型催化剂(bio-CZ-500),研究发现在500℃条件下焙烧制备的bio-CZ-500催化剂在CO_2加氢反应中经过100 h测试活性几乎不变,同时甲醇选择性高达81%。相比之下,无生物模板制备的Cu/ ZnO催化剂显示出较低甲醇选择性(50%),且催化剂在12 h内快速失活。通过透射电镜、扫描电镜、氮气吸脱附、红外光谱、X射线衍射、X射线光电子能谱、接触角测试、程序升温等表征技术揭示了bio-CZ-500催化剂具有多级孔碳结构、丰富的Cu-ZnO活性界面和较高的水接触角。催化剂的弱亲水性加快了副产物水的扩散,促进了中间体分解制甲醇,同时抑制了铜颗粒的烧结失活,从而提高甲醇的选择性与催化剂的稳定性。该工作为制备高效稳定的Cu基工业催化剂提供了新方法。