用于木质素催化湿式氧化反应的纳米空心球钙钛矿催化剂

利用尿素辅助溶剂热法合成了一系列LaFe_xMn_1-xO₃和La_0.9Sr_0.1MnO₃纳米空心球材料,并采用X射线衍射、透射电子显微镜和物理吸附等方法对其晶相、形貌和比表面积进行了表征. 在木质素的催化湿式氧化反应(CWAO)中,该催化剂表现出比传统的柠檬酸溶胶-凝胶法制备的钙钛矿材料更高的催化活性. 这主要是由于空心球结构所致. 当T=120℃,p(O₂)=0.2MPa时,CWAO反应1h后木质素转化率超过80%. 反应后组分离子溶出量很低,表明由于钙钛矿相结构的存在,催化剂在该反应条件下非常稳定.

Perovskite hollow nanospheres for the catalytic wet air oxidation of lignin

A urea-assisted solvothermal-calcination method was used to prepare LaFe_xMn_1-xO₃ and La_0.9Sr_0.1MnO₃ hollow nanospheres, and their crystal phase, morphology, and specific surface area properties were analyzed by X-ray diffraction, transmission electron microscopy, and nitrogen adsorption-desorption isotherms. These materials were then evaluated as catalysts for the catalytic wet air oxidation (CWAO) of lignin, and showed much better catalytic performance than perovskite prepared by the traditional sol-gel method. The structure of the hollow nanospheres has been suggested as the reason of this higher catalytic activity. For the CWAO reaction at 120 ℃ and 0.2 MPa O₂, the conversion of lignin was greater than 80% after 1 h. Analysis of the ions leaching from the material following the completion of the reaction showed that the catalysts were very stable under the reaction conditions because of their perovskite phase structure.