地方城市空间要素规划建设时序研究:以清代台湾省为例*

Cr/PNP催化乙烯选择性齐聚反应制短链线性α-烯烃(LAOs)技术是近年来发展极为迅速的研究方向,其中关于反应微观机理的研究对高性能催化剂设计和研发具有重要意义.通过使用量子化学计算与实验相结合的方法,可以获得对催化反应过程更为深刻的认识.我们主要从理论计算研究的角度,总结了铬系催化剂催化乙烯选择性齐聚研究中取得的最新成果.主要内容包括反应过程中催化剂的氧化态Cr(Ⅰ/Ⅲ) vs Cr(Ⅱ/Ⅳ)],反应路径中单乙烯和双乙烯配位的竞争,配体的空间结构和电子效应,自然键轨道理论(NBO)以及H_2效应对催化体系的影响等.

Planning and Construction Process of Spatial Elements in Cities of Taiwan Province during the Qing Dynasty

The technology of catalyze ethylene to short-chain linear alpha-olefins (LAOs) using chromium-based catalyst is a rapidly developing research direction. This technology has developed rapidly in recent years, and the research of reaction mechanism plays an important role in the screening and development of high-performance catalysts. The mechanism of ethylene selective tri/tetramerization catalyzed by chromium-based catalysts has been investigated using combined quantum chemical calculation and experimental methodologies. It can gain a deeper understanding of the catalytic reaction mechanism, thus providing theoretical guidance for the design and development of new catalysts. This article summarizes the latest achievements in the study of chromium-based catalyzed selective oligomerization mechanism of ethylene from the perspective of theoretical calculation research. Including the oxidation state of the catalyst during the reaction Cr(I/III) vs Cr(II/IV)], single versus double ethylene insertion pathways ,spatial structure and electronic effects of ligands, natural bond orbital theory (NBO) and effects of H2 on chromium-based catalyzed ethylene selective tri/tetramerization .