论文部分内容阅读
为了了解纤维素热解机理,结合相关实验结果对纤维素单体(β-D-吡喃葡萄糖)的热解设计了四种热解反应途径.利用Gaussian 03程序,采用密度泛函理论(DFT),在UB3LYP/6-31G(d)水平上,对各反应物和产物的几何结构进行了能量梯度法全优化,计算了不同温度下各反应路径的热力学参数.计算结果表明:所有反应均为吸热反应;当温度在550K以上时,所有反应都能自发进行.从热力学的角度分析,热解更有利于发生开环反应而形成乙醇醛、1-羟基-2-丙酮、CO等小分子产物.
In order to understand the pyrolysis mechanism of cellulose, four pyrolysis reaction schemes were designed for the pyrolysis of cellulose monomer (β-D-glucopyranose) by using the related experimental results.Using Gaussian 03 program, the density functional theory (DFT ), The geometries of reactants and products were fully optimized by energy gradient method at UB3LYP / 6-31G (d) level, and the thermodynamic parameters of each reaction path at different temperatures were calculated. The calculation results show that all reactions For the endothermic reaction; when the temperature is above 550K, all the reactions can be carried out spontaneously.From the thermodynamic point of view, the pyrolysis is more conducive to the occurrence of ring opening reaction to form glycolaldehyde, 1-hydroxy-2-propanone, CO and other small Molecular products.