【摘要】 在前期研究基础上,设计合成了具有双金属结构的Rh(Ⅰ)-Ru(Ⅲ)催化剂。通过羰基化催化剂性能评价实验,对反应条件进行优化,同时在分子水平上采用密度泛函方法,对Rh(Ⅰ)-Ru(Ⅲ)催化剂催化羰基化各基元反应的反应物、中间体、过渡态及产物进行几何构型优化,计算了各基元反应的反应能垒,所有能量经过零点能校正。结果表明,Rh(Ⅰ)-Ru(Ⅲ)催化剂呈不对称折叠的立体构型,其催化各基元反应能垒均低于Monsanto铑碘催化剂的。在190℃、3.5 MPa、水质量分数6%、醋酸质量分数54%条件下,醋酸甲酯羰基化反应的转化率96.0%、醋酸收率96.0%,且无沉淀生成,明显降低了反应体系水的用量,催化剂表现出优异的稳定性和活性。更多还原

【Abstract】 The Rh(Ⅰ)-Ru(Ⅲ) bimetallic catalyst was synthesized according to Monsanto rhodium catalyst for the reaction of carbonylation to acetic acid. Reaction conditions were optimized by performance evaluation experiments of carbonylation with Rh(Ⅰ)-Ru(Ⅲ) catalyst. Density functional theory was used to study the carbonylation mechanism with Rh-Ru catalyst. Geometries of the reactants, intermediates, transition states and products were optimized by using the above method, and the activation energy of each element reaction was also calculated after correcting the energy of each specie by zero-point energy(ZPE) method. Experimental and calculation results suggest that the Rh(Ⅰ)-Ru(Ⅲ) bimetallic catalyst exbibits the asymmetrical folded stereo configuration, and the reaction activation barrier is lower than that of Monsanto catalyst. Under the conditions of 190 ℃, 3.5 MPa, water mass fraction of 6% and acetic acid mass fraction of 54%, the carbonylation conversion rate can reach 96.0% with 96.0% acetic acid yield. Furthermore, it was found that there is no precipitation occurred during the process. Water usage is also significantly reduced which indicates this catalyst has excellent stability and activity.更多还原