A novel solid-gas process to synthesize LaMnO3 perovskite with high surface area and excellent activity for methane combustion

A novel solid-gas route to prepare LaMnO3 perovskite catalysts for methane combustion has been developed. The method was carried out using a polyvinylpyrrolidone-metal complex as precursor via a solid-gas process to obtain the target materials. The structure and properties of the precursor and the catalysts were characterized by FT-IR, TG-DSC, XRD and N2 adsorption-desorption techniques. The results indicate that the catalysts synthesized via the solid-gas process possess higher surface areas, better thermal resistance and catalytic activity as compared to those prepared with the conventional sol-gel citrate method.     

H+CH3D→H2+CH2D反应的十维量子动力学研究

本文采用最近发展的十维含时波包方法研究了H+CH₃D→H₂+CH₂D反应的模式选择性,计算了反应物CH₃D在基态、CH₃对称和不对称伸缩振动激发态、CD伸缩振动激发态以及CH₃弯曲模式的基频和倍频激发态等6个初始状态下的反应几率. 计算结果表明,在碰撞能0.0∽1.0 eV区间内,激发CH₃的任意一种伸缩振动模都能增强反应活性,而CD伸缩振动激发对反应的促进作用不明显. CH₃弯曲振动模的基频激发对促进反应活性几乎没有影响,由于CH₃对称伸缩振动模的基频与CH₃弯曲振动模倍频之间的费米共振作用,CH₃弯曲振动模的倍频激发显著增强了反应活性.     

适合SBA-15介孔材料工业化生产的改良方法

在SBA-15介孔材料100L中试和2m3工业放大合成基础上,采用多次水解合并晶化、母液循环使用和以工业正硅酸乙酯(TEOS)原料为硅源三种改良方法,提高SBA-15材料的合成效率,减少废酸水排放和降低原料成本.结果表明,母液经加热蒸除乙醇至5%和工业原料TEOS经蒸除沸点低于163oC的前馏分后使用,在有效保证合成出结构性能良好SBA-15材料的同时,可使生产效率提高1倍,分别减少50%和90%三嵌段共聚物和盐酸用量,且几乎无废水排放,最终节约SBA-15原料成本约60%.这些改良方法有利于SBA-15材料工业生产时的环境保护和成本控制,具有很高可行性.