CAJ | 학술논문

采用共沉淀法合成了Cu：Zn：Al：Zr：Y原子比分别为2：1：1：0：0、2：1：0.8：0.2：0、2：1：0.8：0：0.2和2：1：0.8：0.1：0.1的Cu/Zn/Al/(Zr)/(Y)类水滑石化合物.将前驱体材料在空气中500°C焙烧后得到复合金属氧化物,并将其用于CO2加氢合成甲醇反应.采用X射线衍射(XRD)、热重(TG)分析、N2吸附、氧化亚氮(N2O)反应吸附、氢气程序升温还原(H2-TPR)和H2/CO2程序升温脱附(H2/CO2-TPD)技术对所制备的样品进行表征.结果表明, Zr和Y的引入使得催化剂BET比表面积大幅增加,金属铜的比表面积和分散度均按以下顺序依次增加：Cu/Zn/Al<Cu/Zn/Al/Zr<Cu/Zn/Al/Y<Cu/Zn/Al/Zr/Y,然而,强碱位数目占总碱位数目的比例的变化顺序为：Cu/Zn/Al<Cu/Zn/Al/Y<Cu/Zn/Al/Zr/Y<Cu/Zn/Al/Zr.活性评价结果揭示CO2转化率取决于金属铜的比表面积,甲醇选择性则随强碱位比例的增加而线性增加.因而, Zr和Y的引入有利于甲醇的合成, Cu/Zn/Al/Zr/Y催化剂上的甲醇收率最高.
채용공침정법합성료Cu：Zn：Al：Zr：Y원자비분별위2：1：1：0：0、2：1：0.8：0.2：0、2：1：0.8：0：0.2화2：1：0.8：0.1：0.1적Cu/Zn/Al/(Zr)/(Y)류수활석화합물.장전구체재료재공기중500°C배소후득도복합금속양화물,병장기용우CO2가경합성갑순반응.채용X사선연사(XRD)、열중(TG)분석、N2흡부、양화아담(N2O)반응흡부、경기정서승온환원(H2-TPR)화H2/CO2정서승온탈부(H2/CO2-TPD)기술대소제비적양품진행표정.결과표명, Zr화Y적인입사득최화제BET비표면적대폭증가,금속동적비표면적화분산도균안이하순서의차증가：Cu/Zn/Al<Cu/Zn/Al/Zr<Cu/Zn/Al/Y<Cu/Zn/Al/Zr/Y,연이,강감위수목점총감위수목적비례적변화순서위：Cu/Zn/Al<Cu/Zn/Al/Y<Cu/Zn/Al/Zr/Y<Cu/Zn/Al/Zr.활성평개결과게시CO2전화솔취결우금속동적비표면적,갑순선택성칙수강감위비례적증가이선성증가.인이, Zr화Y적인입유리우갑순적합성, Cu/Zn/Al/Zr/Y최화제상적갑순수솔최고.
Cu/Zn/Al/(Zr)/(Y) hydrotalcite-like compounds with Cu:Zn:Al:Zr:Y atomic ratios of 2:1:1:0:0, 2:1:0.8:0.2:0, 2:1:0.8:0:0.2, and 2:1:0.8:0.1:0.1 were prepared using the coprecipitation method. The mixed oxides were then obtained by the calcination of the precursors at 500 °C in air, and subsequently evaluated in terms of their catalytic performance for the synthesis of methanol from the hydrogenation of CO2. The as-prepared samples were characterized by X-ray diffraction (XRD), thermogravimetric (TG) analysis, N2 adsorption, reactive N2O adsorption, H2 temperature-programmed reduction (H2-TPR), and H2/CO2 temperature-programmed desorption (H2/CO2 TPD) techniques. The results of these analyses showed that the BET specific surface area increased significantly with the introduction of Zr and Y, which was related to the amount of H2O and CO2 evolved from the precursors during calcination. The Cu specific surface area and Cu dispersion properties increased in the order of Cu/Zn/Al<Cu/Zn/Al/Zr<Cu/Zn/Al/Y<Cu/Zn/Al/Zr/Y, whereas the proportion of strongly basic sites to total basic sites increased in the order of Cu/Zn/Al<Cu/Zn/Al/Y<Cu/Zn/Al/Zr/Y<Cu/Zn/Al/Zr. The evaluation of these materials as catalysts for the hydrogenation of CO2 revealed that the CO2 conversion was dependent on the Cu specific surface area, and the CH3OH selectivity increased linearly as the proportion of strongly basic sites increased. The introduction of Zr and Y therefore favored the production of methanol and the maximum CH3OH yield was obtained over the Cu/Zn/Al/Zr/Y catalyst.