掺杂钙钛矿载体制备及合成碳酸二苯酯活性评价

Preparation of Substitution-Structure Perovskite Carriers and Activity Evaluation for Synthesis of Diphenyl Carbonate

采用柠檬酸络合物法对LaMnO_3型钙钛矿载体的A位La离子、B位Mn离子进行部分掺杂．选用X射线衍射、电子扫描电镜、X射线光电子能谱对载体的物相、表面形貌、晶体表面元素价态进行分析,发现通过掺杂制备的载体可形成有部分晶体缺陷的晶相,B位离子的高价态比例明显增加．选用不同载体负载活性组分Pd制备的催化剂用于合成碳酸二苯酯,结果表明,具有掺杂缺陷的钙钛矿载体有利于晶格上氧种的转化,增强了载体传递电子进行氧化还原的能力,提高了催化剂的活性．

The perovskite-type compound LaMnO3 was substituted for the part of La in position A and the part of Mn in position B by citrate method. X-ray diffraction （XRD）, ray photoelection spectroscopy （XPS） were used to analyze the sample. It was found that crystalline imperfections were formed increased in the perovskite after doping. Active component Pd scanning electron microscopy （SEM） and X- phase, morphology and atomic valency of the and the proportion of high valent B element was loaded on various perovskite supports for synthesis of diphenyl carbonate（DPC）. The resuhs showed that the activity of catalysts was improved when the supports had lattice defection by substitution. So, it could be concluded that perovskite with lattice defection by doping was favorable to the formation of oxygen vacancy where the lattice oxygen became exchangeab oxygen gas. Therefore, the redox process of carrier was accelerated and the activity of catalysts was le with the improved.