Kulkarni Rajeswari M, Arvind N
Department of Chemical Engineering, M. S. Ramaiah Institute of Technology, MSR Nagar, MSRIT Post, Bangalore, 560054, Karnataka, India.
Heliyon. 2021 Jan 21;7(1):e06018. doi: 10.1016/j.heliyon.2021.e06018. eCollection 2021 Jan.
Synthesis of 1,3- dioxane and 1,3-dioxolane, using sulfated CeO-ZrO catalyst for acetalization of glycerol with benzaldehyde, is the focus of present work. SO /CeO-ZrO catalyst was synthesized using combustion method. Experiments were carried out to analyze the effect of various solvents (n-hexane, toluene, tert-butyl alcohol, pentanol), molar ratios (1:3, 1:5, 1:7), catalyst loadings (3 wt%, 5 wt%, 9 wt %) and temperatures (80 °C, 90 °C, 100 °C) on glycerol conversion and selectivity of the products. Selectivity of 87.20% dioxolane and 12.80% dioxane was obtained at molar ratio of 1:3, 9 wt% catalyst loading and temperature of 100 °C.Strong NH desorption peak from NH-TPD study indicated the high acidic strength of sulphated catalyst. Strong surface acidity and surface porosity (observed from TEM and SEM analysis) contributed to an enhanced activity of the catalyst for glycerol acetalization reaction. The kinetics of the reaction was studied using an elementary kinetic law. A correlation coefficient of 0.98 from the selected kinetic model proved that the rate of acetalization reaction was dependent on glycerol concentration and acetal formation was instantaneous. The study demonstrated the application of an environmentally benign, inexpensive, thermally stable, active SO /CeO-ZrO catalyst for glycerol acetalization reaction to synthesize 1,3-dioxolane as the desired product.
使用硫酸化的CeO-ZrO催化剂催化甘油与苯甲醛缩合反应合成1,3-二氧六环和1,3-二氧五环是当前工作的重点。采用燃烧法合成了SO /CeO-ZrO催化剂。进行实验以分析各种溶剂（正己烷、甲苯、叔丁醇、戊醇）、摩尔比（1:3、1:5、1:7）、催化剂负载量（3 wt%、5 wt%、9 wt%）和温度（80℃、90℃、100℃）对甘油转化率和产物选择性的影响。在摩尔比为1:3、催化剂负载量为9 wt%、温度为100℃的条件下，二氧五环的选择性为87.20%，二氧六环的选择性为12.80%。NH-TPD研究中强烈的NH脱附峰表明硫酸化催化剂具有高酸性强度。较强的表面酸性和表面孔隙率（通过TEM和SEM分析观察到）有助于提高催化剂对甘油缩合反应的活性。使用基元动力学定律研究了该反应的动力学。所选动力学模型的相关系数为0.98，证明缩合反应速率取决于甘油浓度，且缩醛形成是瞬时的。该研究证明了一种环境友好、廉价、热稳定、活性高的SO /CeO-ZrO催化剂在甘油缩合反应中用于合成所需产物1,3-二氧五环的应用。
