CAJ | 학술논문

采用尿素水解法制备了Cu/SiO2催化剂,探究其用于乙酸甲酯(MA)加氢制取乙醇的催化性能,并通过N2物理吸附、X射线衍射(XRD)、程序升温还原(TPR)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等表征方法分析了催化剂的物理化学特性,探究了铜负载量和还原温度等对催化剂结构的影响,以及与催化活性之间的关系.发现在铜负载量分别为10%、20%和30%(质量分数, w)的催化剂中,铜负载量为20%的催化剂因具有较多且分散均匀的活性组分而表现出最佳的加氢效果.接着在铜负载量为20%的催化剂上研究了还原温度(270,350,450°C)对催化性能的影响,发现在350°C下还原的催化剂活性最高,在最佳的反应条件下,乙酸甲酯转化率达到97.8%,乙醇选择性达到64.9%(理论最大值为66.6%),主要归属于它具有较高的铜物种分散度,最合适的Cu0/(Cu0+Cu+)摩尔比例,同时实现了解离氢气和活化乙酸甲酯的功能.
채용뇨소수해법제비료Cu/SiO2최화제,탐구기용우을산갑지(MA)가경제취을순적최화성능,병통과N2물리흡부、X사선연사(XRD)、정서승온환원(TPR)、투사전자현미경(TEM)화X사선광전자능보(XPS)등표정방법분석료최화제적물이화학특성,탐구료동부재량화환원온도등대최화제결구적영향,이급여최화활성지간적관계.발현재동부재량분별위10%、20%화30%(질량분수, w)적최화제중,동부재량위20%적최화제인구유교다차분산균균적활성조분이표현출최가적가경효과.접착재동부재량위20%적최화제상연구료환원온도(270,350,450°C)대최화성능적영향,발현재350°C하환원적최화제활성최고,재최가적반응조건하,을산갑지전화솔체도97.8%,을순선택성체도64.9%(이론최대치위66.6%),주요귀속우타구유교고적동물충분산도,최합괄적Cu0/(Cu0+Cu+)마이비례,동시실현료해리경기화활화을산갑지적공능.
Cu/SiO2 catalysts for the hydrogenation of methyl acetate (MA) to ethanol were prepared using the urea hydrolysis method. The catalysts were characterized using N2-physisorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The effects of the copper loading and reduction temperature on the catalyst structure and catalytic performance were investigated. Experimental studies of the influence of the copper loading showed that a 20%(mass fraction, w) Cu/SiO2 catalyst had uniformly dispersed copper particles and a large number of active centers, and therefore gave the best hydrogenation performances among the three catalysts with the copper loadings of 10%, 20%, and 30%, respectively. Then 20% (w) Cu/SiO2 was reduced at different temperatures (270, 350, and 450 °C). The results showed that 20%(w) Cu/SiO2 reduced at 350 °C had the best catalytic activity. This was attributed to the homogeneous distribution of copper nanoparticles, and appropriate Cu0/(Cu0+Cu+) molar ratio, which achieved simultaneous dissociation of hydrogen and MA activation. Under the optimum reaction conditions, the MA conversion and ethanol selectivity reached 97.8%and 64.9%(theoretical maximum value:66.6%), respectively.