美国 Delaware 大学通过理论计算和实验方法,研究了乙烯环氧化反应机理和催化剂设计,设计出的催化剂比目前工业应用的银基催化剂具有更高的选择性。几年前,该大学研究人员发现氧杂金属环(oxametallacycle)(即两端与金属表面相连的-O-C-C-结构)是环氧化反应的主要中间体。该物种是在量子力学计算与表面科学测量相结合的基础上发现的。研究人员认为氧杂金属环可继续形成所需产物环氧乙烷,或者生成乙醛,并进一步生成无用副产物,但这两种反应途径都存在选择性较低的问题。因此研究人员采用了计算机筛选方法对可提高环氧化反应选择性的银基过渡金属催化剂 Delaware University of the United States through theoretical calculations and experimental methods, ethylene epoxidation reaction mechanism and catalyst design, the design of the catalyst than the current industrial application of silver-based catalyst has a higher selectivity. Several years ago researchers at the university discovered that the oxametallacycle (the -O-C-C structure connected to the metal surface at both ends) is the main intermediate for epoxidation. The species was discovered on the basis of a combination of quantum mechanics and surface science measurements. The researchers believe that the oxa metal ring can continue to form the desired product ethylene oxide, or generate acetaldehyde, and further generate unwanted by-products, but there are two options for the lower selectivity of the problem. Therefore, the researchers used a computer screening method can improve the selectivity of the epoxidation of silver-based transition metal catalyst