论文部分内容阅读
针对四氯化硅催化氢化过程采用第一性原理机理对其进行模拟研究,结果表明:没有催化剂时,SiCl4与H2反应能垒为464.45 kJ/mol,反应能量为74.94 kJ/mol,与热力学计算结果 71.85 kJ/mol一致.负载在HZSM-5分子筛上的氯化钡可催化四氯化硅氢化反应,其最具催化活性表面为(111)面;H2在BaCl2(111)面上表现排斥性;SiCl4表现为吸附性,可在BaCl2(111)表面稳定吸附并生成.SiCl3自由基,过程吸附能为448.33 kJ/mol;在催化剂BaCl2存在条件下,SiCl4与H2反应为自由基反应,反应步骤能垒为400.23 kJ/mol;氢化过程能垒降为184.97kJ/mol;催化氢化反应过程所需能量为64.20 kJ/mol.催化氢化过程反应条件相对无催化剂过程更为温和.
The first-principle mechanism of the catalytic hydrogenation of silicon tetrachloride was used to simulate the reaction. The results show that without the catalyst, the energy barrier of SiCl4 and H2 reaction is 464.45 kJ / mol and the reaction energy is 74.94 kJ / mol. The results were consistent with 71.85 kJ / mol. Barium chloride supported on HZSM-5 zeolite could catalyze the hydrogenation of silicon tetrachloride. The most catalytically active surface was (111) surface. H2 showed repellency on BaCl2 (111) surface ; SiCl4 was adsorbed on the surface of BaCl2 (111) and formed SiCl3 free radicals, the process of adsorption energy was 448.33 kJ / mol; In the presence of BaCl2 catalyst, the reaction of SiCl4 and H2 was free radical reaction, the reaction step The energy barrier is 400.23 kJ / mol, the energy barrier of hydrogenation process is 184.97 kJ / mol, the energy required for catalytic hydrogenation process is 64.20 kJ / mol, and the reaction conditions in catalytic hydrogenation process are more gentle than those without catalyst.