采用沉淀方法制备了氧化铬催化剂,并用于NO催化氧化反应,首次发现该催化剂具有常温氧化活性,考察了沉淀剂和焙烧温度等制备条件对其活性的影响。结果发现,相比于常规的活性炭及活性炭纤维,氧化铬催化剂在常温催化氧化NO方面表现出了更...采用沉淀方法制备了氧化铬催化剂,并用于NO催化氧化反应,首次发现该催化剂具有常温氧化活性,考察了沉淀剂和焙烧温度等制备条件对其活性的影响。结果发现,相比于常规的活性炭及活性炭纤维,氧化铬催化剂在常温催化氧化NO方面表现出了更加优异的活性及稳定性,当NO质量分数为15μg/g,空速为43 200 m L/h时,可维持800 min以上100%净化率,采用氨水、碳酸氢铵、氢氧化钾作为沉淀剂时,300℃焙烧得到的氧化铬催化剂具有很好的活性及稳定性。展开更多
A Cr/SBA-16 catalyst was prepared using Cr（NO3）3 as a precursor and mesoporous silica SBA-16 as a support via a simple impregnation method. The catalyst was characterized using wide-angle X-ray diffraction （XRD）, ...A Cr/SBA-16 catalyst was prepared using Cr（NO3）3 as a precursor and mesoporous silica SBA-16 as a support via a simple impregnation method. The catalyst was characterized using wide-angle X-ray diffraction （XRD）, low-angle XRD, N2 adsorption-desorption, transmission electron microscopy, and ultraviolet-visible spectroscopy. The catalyst activity was investigated in the direct bydroxylation of benzene to phenol using H2O2 as the oxidant. Various operating variables, namely reaction temperature, reaction time, amount of H2O2, and catalyst dosage, were optimized using central composite design combined with response surface methodology （RSM）. The results showed that the correla- tion between the independent parameters and phenol yield was represented by a second-order polynomial model. The high correlation coefficient （R2）, i.e., 0.985, showed that the data predicted using RSM were in good agreement with the experimental results. The optimization results also showed that high selectivity for phenol was achieved at the optimized values of the operating variables： reaction temperature 324 K, reaction time 8 h, H2O2 content 3.28 mL, and catalyst dosage 0.09 g. This study showed that RSM was a reliable method for optimizing process variables for benzene hydroxylation to phenol.展开更多
文摘采用沉淀方法制备了氧化铬催化剂,并用于NO催化氧化反应,首次发现该催化剂具有常温氧化活性,考察了沉淀剂和焙烧温度等制备条件对其活性的影响。结果发现,相比于常规的活性炭及活性炭纤维,氧化铬催化剂在常温催化氧化NO方面表现出了更加优异的活性及稳定性,当NO质量分数为15μg/g,空速为43 200 m L/h时,可维持800 min以上100%净化率,采用氨水、碳酸氢铵、氢氧化钾作为沉淀剂时,300℃焙烧得到的氧化铬催化剂具有很好的活性及稳定性。
基金the University of Tehran for financial support of this work
文摘A Cr/SBA-16 catalyst was prepared using Cr（NO3）3 as a precursor and mesoporous silica SBA-16 as a support via a simple impregnation method. The catalyst was characterized using wide-angle X-ray diffraction （XRD）, low-angle XRD, N2 adsorption-desorption, transmission electron microscopy, and ultraviolet-visible spectroscopy. The catalyst activity was investigated in the direct bydroxylation of benzene to phenol using H2O2 as the oxidant. Various operating variables, namely reaction temperature, reaction time, amount of H2O2, and catalyst dosage, were optimized using central composite design combined with response surface methodology （RSM）. The results showed that the correla- tion between the independent parameters and phenol yield was represented by a second-order polynomial model. The high correlation coefficient （R2）, i.e., 0.985, showed that the data predicted using RSM were in good agreement with the experimental results. The optimization results also showed that high selectivity for phenol was achieved at the optimized values of the operating variables： reaction temperature 324 K, reaction time 8 h, H2O2 content 3.28 mL, and catalyst dosage 0.09 g. This study showed that RSM was a reliable method for optimizing process variables for benzene hydroxylation to phenol.
