不同形貌ZnO与Cu的相互作用及对醋酸异丙酯加氢性能的影响  

Synergy between Different Morphology ZnO/Cu and their Effects on Isopropyl Acetate Hydrogenation

作　　者：王森[1] 崔咪芬[1] 费兆阳[1,2] 陈献[1] 汤吉海[1] 乔旭[1,2] WANG Sen;CUI Mi-fen;FEI Zhao-yang;CHEN Xian;TANG Ji-hai;QIAO Xu(Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing 210009, China;State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009, China)

机构地区：[1]南京工业大学化学化工学院,江苏省工业节水减排重点实验室,江苏南京210009 [2]南京工业大学材料化学工程国家重点实验室,江苏南京210009

出　　处：《高校化学工程学报》2017年第1期51-57,共7页Journal of Chemical Engineering of Chinese Universities

基　　金：江苏高校优势学科建设工程资助项目(PADD)

摘　　要：采用水热法并通过控制前驱体溶液的浓度合成了不同形貌的盘状和柱状ZnO晶体,并通过X射线衍射(XRD)、扫描电镜(SEM)、透射电子显微镜(TEM)、选区电子衍射(SAED)、拉曼光谱(Raman)及氢气程序升温还原(H2-TPR)等表征其形貌结构、生长习性及其与Cu之间的相互作用。发现随着前驱体溶液浓度的减小,ZnO晶体结构逐渐延长,六边形极性面直径减小,形状由盘状向柱状转变。然后分别将这些ZnO晶体作为助剂制备了不同形貌的Cu/ZnO催化剂,并用于醋酸异丙酯(IA)加氢合成乙醇和异丙醇的反应。结果发现:ZnO晶体的形貌结构对IA加氢催化性能有明显的影响,盘状Cu/ZnO-a催化剂具有最高的IA转化率和产物选择性;对催化活性与ZnO极性面所占比例进行了关联,得到了较好的线性关系,极性面比例越高,IA转化率越高。这归因于极性面比例较高的ZnO与Cu之间的相互作用更强,活性组分铜的分散更均匀、更容易还原,从而使催化加氢活性更高。Plate and rod-like hexagonal ZnO crystals were synthesized via a facile solution by adjusting precursor concentration. Crystal structure, growth habit and synergy between Cu and different morphology ZnO were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectra and H2 temperature-programmed reduction (H2-TPR). The results show that ZnO crystals are elongated along the length axis and the plane diameter is reduced with the decreaseof precursor concentration, which leads to morphology evolution from hexagonal plate to prismatic rod. The resulted ZnO crystals were used as a co-catalyst of copper for isopropyl acetate hydrogenation to prepareethanol and isopropanol. The results indicate that ZnO morphology have a significant impact on isopropyl acetate hydrogenation. The Plate-like Cu/ZnO-a catalyst has the highest isopropyl acetate conversion rate and selectivity. A linear relationship between the percentage of polar plane surface area and conversion rate is identified. The isopropyl acetate conversion rate increases with the increase of polar surface percentage, whichis because higher polar surface ratio of ZnO can lead to stronger interaction between ZnO and Cu. Moreover,the active component (copper) is better dispersed and easier to be reduced, which results in better catalytic hydrogenation performance.

关 键 词：ZnO形貌 极性面 醋酸异丙酯 加氢 乙醇 异丙醇 

分 类 号：TQ-032.4[化学工程]