文献类型：期刊文献

英文题名：Cationic Pyridylamido Adsorbate on Bronsted Acidic Sulfated Zirconia: A Molecular Supported Organohafnium Catalyst for Olefin Homo- and Co-Polymerization

作者：Zhang, Jialong[1,2];Motta, Alessandro[3,4];Gao, Yanshan[2];Stalzer, Madelyn Marie[2];Delferro, Massimiliano[2,5];Liu, Boping[1,6];Lohr, Tracy L.[2];Marks, Tobin J.[2]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Northwestern Univ, Dept Chem, Evanston, IL 60208 USA;[3]Univ Roma La Sapienza, Dipartimento Sci Chim, I-00185 Rome, Italy;[4]UdR Roma, INSTM, I-00185 Rome, Italy;[5]Argonne Natl Lab, Chem Sci & Engn Div, Argonne, IL 60439 USA;[6]South China Agr Univ, Coll Mat & Energy, Guangzhou 510642, Guangdong, Peoples R China

年份：2018

卷号：8

期号：6

起止页码：4893

外文期刊名：ACS CATALYSIS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000434369600016)】；

基金：Financial support of this heterogeneous catalytic project by the U.S. Department of Energy through grant DE FG02-03ER15457 to the Institute for Catalysis in Energy Processes (ICEP) at Northwestern University is gratefully acknowledged (J.Z., M.M.S.), while complementary homogeneous catalyst design work was supported by NSF grant CHE-1464488 (T.L.L). The purchase of the NMR instrumentation at IMSERC at Northwestern University was supported by NSF (CHE-1048773). Computational resources supporting this work were provided by the Northwestern University Quest High Performance Computing cluster (T.L.L.) and CINECA award N. HP10CBHAYD 2014 under the ISCRA initiative (A.M). We thank UOP, a Honeywell Company (Des Plaines, IL) for the generous gift of sulfated zirconia. We also thank Albemarle Corp. for a generous gift of triphenylcarbenium tetrakis(pentafluorophenyl)borate, Ph3C+B(C6F5)4-. We thank Y. Wang and J.Z. Chen of Northwestern University for helpful discussions. J.Z. thanks the joint-Ph.D. program supported by China Scholarship Council for fellowships.

语种：英文

外文关键词：organohafnium catalyst; olefin polymerization; sulfated oxides; supported catalysts; DFT calculations

摘要：Here we report the combined application of high resolution solid-state C-13-CPMAS-NMR and FT-IR spectroscopy, elemental analysis, kinetic poisoning/active site counting, variable dielectric constant medium, and DFT computation to characterize the surface chemistry of a pyridylarnido hafnium complex (Cat1, L-1-HfMe2, L-1 = 2,6-diisopropyl-N-{(2-isopropylphenyl))[6-(naphthalen-1-yl)pyridin-2-yl]methyl}aniline) adsorbed on Bronsted acidic sulfated zirconia (ZrS). The spectroscopic and DFT results indicate protonolytic formation of organohafnium cations having a largely electrostatic pyridylamido-Hf-CH3+ ... ZrS- interaction with elongated Hf ... OZES distances of, similar to 2.14 A. High-molecular-weight polyethylenes and ethylene/1-octene copolymers are obtained with this supported catalyst without an activator/cocatalyst. The DFT calculations reveal that the first ethylene insertion into the Hf-methyl bond has a lower barrier than the corresponding insertion into the Hf-aryl bond of this single-site heterogeneous catalyst.