Ni functionalized metal organic frameworks (MOF) are promising heterogeneous ethene dimerization catalysts. Activities comparable to or higher than Ni-aluminosilicates have been reported in literature. However, unlike the Ni-aluminosilicates, those Ni-MOFs require a large excess of co-catalyst to initiate the dimerization process and some catalysts generate polymers which lead to catalyst deactivation. Herein, we report a series of Ni(II) and 2,2′-bipyridine-5,5′-dicarboxylate (bpy) functionalized UiO-67 MOF that catalyze the ethene dimerization reaction co-catalyst free. The catalysts were active for ethene dimerization (up to 850 mg butene g_cat⁻¹ h⁻¹) after activation at 300 °C in 10 % O₂ for 360 min and subsequent exposure to flowing ethene (P(ethene) =26 bar, 250 °C) for 240 min. The catalysts yielded up to 6 % conversion with 99 % selectivity to linear 1- and 2-butenes, which formed in non-equilibrated ratios. Overall, the test data indicate that all three linear butenes are formed on a single active site, in accordance with the Cossee-Arlman mechanism. Ex situ XAS and CO FT-IR spectroscopy studies point towards Ni monomers or, plausibly, low-nuclearity Ni-multimers, docked at bpy linkers with Ni-Ni distances > 4 Å, as the main active site for the ethene dimerization reaction.

Ni官能化的金属有机骨架（MOF）是有前途的异质乙烯二聚催化剂。在文献中已经报道了与镍铝硅酸盐相当或更高的活性。但是，与Ni-铝硅酸盐不同，这些Ni-MOF需要大量过量的助催化剂来引发二聚过程，并且某些催化剂会生成导致催化剂失活的聚合物。在这里，我们报告了一系列的Ni（II）和2,2'-联吡啶-5,5'-二羧酸酯（bpy）官能化的UiO-67 MOF，可催化游离出的乙烯二聚反应。在10％O _2中于300°C活化后，催化剂对乙烯二聚反应（至多850 mg丁烯g _cat ^-1  h ^-1）具有活性。持续360分钟，然后暴露于流动的乙烯（P（乙烯）= 26 bar，250°C）中240分钟。催化剂产生高达6％的转化率，对线性1-丁烯和2-丁烯的选择性为99％，它们以非平衡的比例形成。总体而言，测试数据表明，根据Cossee-Arlman机理，所有三个线性丁烯均在单个活性位点上形成。易地XAS和CO FT-IR光谱法的研究指向的Ni单体或，振振有词，低核性的Ni-多聚体，停靠在与镍Ni的距离> 4埃BPY连接体，作为主要的活性位点的乙烯二聚反应。