Unprecedented High Activity of One-Dimensional Nickel-Based Coordination Polymer for Ethylene Dimerization

Abstract

Three kinds of one-dimensional nickel-based coordination polymers (1D-S-Ni, 1D-D-Ni, and 1D-M-Ni) with different coordination environments and topological structures were synthesized and evacuated as heterogeneous catalysts for liquid phase slurry reaction of ethylene dimerization. Their crystal structures, morphology, chemical groups, and thermal properties were characterized by PXRD, SEM, FT-IR, TGA, ICP-AES, and EA, respectively. The catalytic performance of these catalysts was examined under various reaction conditions, including the amount of cocatalyst, reaction temperature, and reaction pressure. These catalysts showed high catalytic activity up to 10⁵–10⁶ g/(molNi·h) and high selectivity of butene (C4) over 78% at room temperature and 10 atm pressure. Especially the catalytic activity of 1D-D-Ni was up to 17.1 × 10⁵ g/(molNi·h), exceeding that of most Ni-based heterogeneous catalysts and reaching the level of nickel-based homogeneous catalysts. The stability and cyclic performance of 1D-D-Ni was also assessed. It was observed that the catalyst did not undergo decomposition during the reaction and maintained a high activity level of 12.0 × 10⁵ g/(molNi·h) even after three cycles. 1D-D-Ni has SBU similar to homogeneous nickel-based complex catalyst for ethylene dimerization, indicating that reasonable design of metal nodes is an effective way to synthesize heterogeneous ethylene dimerization catalysts with high catalytic performance.