CAJ | 학술논문

采用浸渍方法制备不同氧化铜含量的CuO/γ-Al2O3催化剂.使用XRD、SEM和程序控制升温还原(TPR)方法研究γ-Al2O3载体表面氧化铜的分布情况.用X射线定量分析方法得到氧化铜在γ-Al2O3中的分散阈值为0.275g/g,即0.275CuAl.当氧化铜负载量小于或大于其分散阈值时,高度分散或结晶状氧化铜将会出现在γ-Al2O3载体表面.TPR实验表明0.1CuAl和纯CuO还原温度范围分别为420-690℃和290-380℃.氧化铜与载体之间的相互作用导致0.1CuAl不易被还原.0.5CuAl呈现2个分步还原温度范围,分别为210-300℃和410-730℃,证实了γ-Al2O3载体表面高度分散和结晶状分布的氧化铜.硫化实验表明,最佳氧化铜负载量小于其分散阈值,氧化铜以亚单层形式分布在γ-Al2O3载体表面.
채용침지방법제비불동양화동함량적CuO/γ-Al2O3최화제.사용XRD、SEM화정서공제승온환원(TPR)방법연구γ-Al2O3재체표면양화동적분포정황.용X사선정량분석방법득도양화동재γ-Al2O3중적분산역치위0.275g/g,즉0.275CuAl.당양화동부재량소우혹대우기분산역치시,고도분산혹결정상양화동장회출현재γ-Al2O3재체표면.TPR실험표명0.1CuAl화순CuO환원온도범위분별위420-690℃화290-380℃.양화동여재체지간적상호작용도치0.1CuAl불역피환원.0.5CuAl정현2개분보환원온도범위,분별위210-300℃화410-730℃,증실료γ-Al2O3재체표면고도분산화결정상분포적양화동.류화실험표명,최가양화동부재량소우기분산역치,양화동이아단층형식분포재γ-Al2O3재체표면.
CuO/γ-Al2O3 catalysts were prepared by impregnation with different CuO loadings.The dispersion of CuO supported on γ-Al2O3 support was studied using X-ray diffraction (XRD),scanning electron microscopy (SEM),and temperature programmed reduction (TPR).The dispersion threshold of CuO in γ-Al2O3 determined by X-ray quantitative analysis was 0.275 g/g,i.e.,0.275CuA1.Highly dispersed CuO or crystalline CuO would appear on the γ-Al2O3 support when CuO loading was below or more than its dispersion threshold.TPR experiments show that reduction peak temperature ranges of 0.1 CuAl and pure CuO are 420-690 ℃ and 290-380 ℃,respectively.0.1CuAl is not easily reduced due to interaction between CuO and γ-Al2O3.0.5CuAl shows a two-step reduction range during 210-300 ℃ and 410-730 ℃,which confirms the existence of highly dispersed CuO and crystalline CuO.The sulfation experiments show the optimal CuO loading amount is far below its dispersion threshold,and copper oxide supported on γ-Al2O3 is in the form of submonolayer.