粒度对纳米体系化学反应热力学性质的影响  

Effects of Particle Size on Properties of Chemical Reaction Thermodynamics of Nanosystems

作　　者：来蔚鹏[1] 薛永强[2] 廉鹏[1] 葛忠学[1] 王伯周[1] 张志忠[1] 

机构地区：[1]西安近代化学研究所,西安710065 [2]太原理工大学应用化学系,太原030024

出　　处：《物理化学学报》2007年第4期508-512,共5页Acta Physico-Chimica Sinica

基　　金：山西省自然科学基金(20021016)资助项目

摘　　要：为了研究纳米粒子的粒度对化学反应热力学性质的影响规律,以球形原子簇来模拟纳米金刚石颗粒,用量子化学方法对粒度不同的金刚石纳米粒子与氧气反应的热力学性质进行了计算.结果表明,粒度对多相反应的标准摩尔反应焓△_rH_m^0、标准摩尔反应熵△_rS_m^0、标准摩尔反应吉布斯函数△_rG_m^0和标准平衡常数K^0均有明显的影响,随着反应物粒径的减小,△_rH_m^0、△_rS_m^0和△_rG_m^0均降低,而K^0增大.这些影响规律与实验结果基本一致.In order to study size dependence of the thermodynamic properties of chemical reaction, nanoparticles of diamond were simulated by use of spherical C clusters, the properties of chemical reaction of diamond nanoparticles with different sizes and O2 were calculated by quantum chemistry method. The results showed that the particle size had obvious effects on the molar standard entropy of reaction, the molar standard enthalpy of reaction, the molar standard Gibbs free energy, and the standard equilibrium constant in heterogeneous reactions; the molar standard entropy of reaction, the molar standard enthalpy of reaction, and the molar standard Gibbs free energy decreased and the standard equilibrium constant increased with the particle diameters of reactants decreasing. These regularities were consistent with experimental results.

关 键 词：纳米粒子 量子化学 粒度 热力学性质 标准摩尔反应焓 标准摩尔反应熵 标准摩尔反应吉布斯函数 标准平衡常数 

分 类 号：O642.1[理学—物理化学]