Cyclopropanation on a highly active heterogeneous catalyst: CuO/TiO2-Al2O3

Some heterogeneous catalysts, cupric oxide supported on different supports, were prepared and employed to catalyze the cyclopropanation of styrene and 2,5-dimethyl-2,4-hexadiene with ethyl diazoacetate (EDA). The catalytic performance for cyclopropanation strongly depends on the nature of the support. A novel catalyst, CUO/TiO2-Al2O3, in which Al2O3 is modified with a monolayer TiO2, is found to be most active and selective for the cyclopropanation reaction. The yields of 93 and 94% cyclopropanes are obtained for styrene and 2,5-dimethyl-2,4-hexadiene at 40 degreesC as the substrates, respectively. The activity and selectivity in cyclopropanes are optimized with a monolayer dispersion of cupric oxide on the corresponding supports. (C) 2002 Elsevier Science B.V. All rights reserved.

CO_2在TiO_2-CuO修饰Cu电极上的光电化学还原

制备了TiO2-CuO修饰Cu电极,并对CO2在该复合光电电极上的还原行为进行了研究。光电化学测试表明,TiO2有助于电极的光电转换,能注入更多的电子促进CO2还原。TiO2-CuO/Cu复合电极在光照条件下对CO2具有很好的光电催化还原活性,使还原电位正移约100 mV,同时有效地抑制了水的光电分解。Mott-Schottky曲线测定表明,TiO2-CuO/Cu复合电极具有n型半导体性质,其平带电位随光照时间的增加而负移。光谱及色质谱测试证明,CO2在TiO2-CuO/Cu复合电极上的光电化学还原产物为甲酸和甲醛,还有少量乙烯和甲烷。在-1.2 V条件下光照3 h,CO2的转化率可达32%。基于实验结果对CO2光电还原机理进行了推断。

用于烟气脱硝的堇青石基CuO/γ-Al2O3催化剂及制法和应用

一种用于烟气脱硝的堇青石基ＣｕＯ／γ－Ａｌ↓［２］Ｏ↓［３］催化剂重量百分比组成为：堇青石载体为７８．７－９３．８％，Ａｌ↓［２］Ｏ↓［３］为５－１６％，ＣｕＯ为１．２－５．３％。采用以高强度堇青石蜂窝陶瓷为基体，在其上涂敷载体γ－Ａｌ↓［２］Ｏ↓［３］后在浸渍一定浓度的ＣｕＯ。本发明具有采用简易高效的涂层方法，减少了γ－Ａｌ↓［２］Ｏ↓［３］膜的涂层裂痕，增加了γ－Ａｌ↓［２］Ｏ↓［３］涂层的牢固度。增加了γ－Ａｌ↓［２］Ｏ↓［３］的上载量；提高了催化剂的脱硝活性，寿命和稳定性的优点。

一种CuO/Al2O3脱硫剂的再生方法

一种ＣｕＯ／Ａｌ＃－［２］Ｏ＃－［３］脱硫剂的再生方法是将吸硫的ＣｕＯ／γ－Ａｌ＃－［２］Ｏ＃－［３］脱硫剂在含氨气气氛中还原再生，再生温度为３５０－５００℃，空速为５００－３０００ｈ＃＋［－１］，再生时间为３０－９０分钟。本发明的再生过程简单，易操作，二次脱硫活性稳定，可实现脱硫温度下的有效还原再生；再生过程中生成的ＳＯ＃－［２］在低温条件下可与未反应的ＮＨ＃－［３］结合生成固体硫酸铵盐，不仅简化了再生后续处理工序，而且可增强本再生方法的经济效益，降低了脱硫综合成本。