Jesudoss S K, Vijaya J Judith, Sivachidambaram M, Kennedy L John, Jothiramalingam R, Al-Lohedan Hamad A
Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College (Autonomous), Chennai 600034, India.
Materials Division, School of Advanced Sciences, Vellore Institute of Technology (VIT) University, Chennai Campus, Chennai 600127, India.
J Nanosci Nanotechnol. 2018 Aug 1;18(8):5367-5379. doi: 10.1166/jnn.2018.15387.
Hierarchical ordered ZSM-5 zeolites were successfully synthesized by a template-free hydrothermal treatment using rice joints ash as the source of silica. The formation of hierarchical ordered ZSM-5 zeolites and its physicochemical properties were investigated systematically. The mineralogical phases, morphology, surface area and porosity, acidity and thermal stability of the synthesized hierarchical materials were investigated using XRD, FT-IR, HR-SEM, N2 adsorption-desorption (BET) analysis, NH3-TPD and TGA/DTA analysis. The excellent catalytic activity of hierarchical ordered ZSM-5 zeolites (150 °C) was revealed in the selective oxidation of toluene to the corresponding benzaldehyde with 82% conversion and 94% selectivity. The material was evaluated for the oxidation of toluene in the presence of H2O2 as the oxidizing agent and 1,4-dioxane solvent. The obtained results noted that the material was highly active, stable and can be recycled at least four times without a loss of catalytic efficiency. The crystallization was carried out in an autoclave for 5 days maintained at a temperature of 150 °C for the transformation of RJA into hierarchical ZSM-5 zeolite structure as well as to achieve high crystallinity.
以稻秸灰为硅源，通过无模板水热法成功合成了分级有序的ZSM-5沸石。系统研究了分级有序ZSM-5沸石的形成及其物理化学性质。采用XRD、FT-IR、HR-SEM、N2吸附-脱附（BET）分析、NH3-TPD和TGA/DTA分析等方法，对合成的分级材料的矿物相、形貌、表面积和孔隙率、酸度和热稳定性进行了研究。在150℃下，分级有序ZSM-5沸石在甲苯选择性氧化为相应苯甲醛的反应中表现出优异的催化活性，转化率为82%，选择性为94%。在以H2O2为氧化剂和1,4-二氧六环为溶剂的条件下，对该材料进行了甲苯氧化性能评价。结果表明，该材料具有高活性、稳定性好的特点，至少可循环使用4次而不损失催化效率。在150℃的温度下，在高压釜中进行5天的晶化处理，使稻秸灰转化为分级ZSM-5沸石结构，并获得高结晶度。
