溶液燃烧法制备LiCoO_2及其同时催化去除碳烟和NO_x性能研究

采用溶液燃烧法和盐助溶液燃烧法制备铜铁矿结构(ABO2)的钴酸锂(Li Co O2)系列催化剂,通过XRD、BET、ICP、XPS、H2-TPR、程序升温反应等手段对其进行了结构表征与性能评价.研究了溶液燃烧法中燃料尿素以及助剂无机盐Na Cl的用量对所制备的催化剂性能影响.实验结果表明,在尿素过量100%时所制备的催化剂结晶程度及催化氧化性能较好,起燃温度达到270℃,N2的转化率达到36.9%.适量助剂Na Cl的引入显著地提高了催化剂比表面积,增加了催化剂表面活性物种,增强了催化剂的氧化还原能力,进而提升催化剂的活性.其中50%质量分数的Na Cl添加量制备的催化剂具有最低的碳烟起燃温度(246℃),但添加Na Cl对NOx的转化率影响不大.

Solution Combustion Synthesis of LiCoO2 for Simultaneously Catalytic Removal of Soot and NOx

LiCoO2 catalysts were prepared by solution combustion synthesis method and salt-assisted combustion method. XRD, BET, ICP, XPS, H2-TPR were adopted to characterize the prepared catalysts and the catalytic activity of the catalysts were evaluated by the temperature programmed reaction. The effects of urea and NaCl addition with different amount were investigated separately. It was showed that the catalyst had a better activity performance when urea excessed 100% compared to stoichiometric amount and had minimum light-off temperatue (270°C) and maximum conversion of NOx to N2(36.9%). Depending on the amount of NaCl, the specific surface area had improved. When NaCl added 50% amount compared to the target product, the light-off temperature decreased to 246°C. However, the addition NaCl has slight influence on conversion of NOx to N2.