Electrocatalysis ( IF 2.7 ) Pub Date : 2022-01-20 , DOI: 10.1007/s12678-022-00708-8
Zhicheng Niu 1 , Lemin Yang 1 , Yongxin Xiao 1 , Min Xue 1 , Jiarong Zhou 1 , Chunlin Ni 1 , Lei Zhang 2 , Jiujun Zhang 3 , David P. Wilkinson 4
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Three molecular catalysts based on mononuclear nickel(II) complexes with square planar geometries, [BzPy]2[Ni(mnt)2] (1), [BzPy]2[Ni(i-mnt)2] (2), and [BzPy]2[Ni(tdas)2] (3) (BzPy = benzyl pyridinium) are synthesized by the reaction of NiCl2∙6H2O, [BzPy]Br, and Na2(mnt)/Na2(i-mnt)/Na2(tdas) (mnt = 1,2-dicyanoethylene-1,2-dithiolate for (1), i-mnt = 2,2-dicyanoethylene-1,1-dithiolate for (2), and tdas = 1,2,5-thiadiazole-3,4-dithiolate for (3)), respectively. The structures and compositions of these three catalysts are characterized by XRD, elemental analysis, FT-IR, and ESI-MS. The electrochemical properties and the corresponding catalytic activities of these three catalysts are studied by cyclic voltammetry. The controlled-potential electrolysis with gas chromatography analysis confirms the hydrogen production with a turnover frequency (TOF) of 116.89, 165.51, and 189.16 moles of H2 per mole of catalyst per hour at a potential of − 0.99 V (versus SHE) in acetonitrile solutions containing the catalysts, respectively. In a neutral buffer solution, these three molecular catalysts exhibit a TOF of 411.85, 488.76, and 555.06 mol of H2 per mole of catalyst per hour at a potential of − 0.49 V (versus SHE), respectively, indicating that Complex 3 constitutes the better active catalyst than Complexes 1 and 2. For fundamental understanding, a catalytic HER mechanism is also proposed.
Graphical abstract
中文翻译：
用于在非水和水溶液中制氢的电化学析氢反应的新型二硫烯镍络合物催化剂
基于具有方形平面几何形状的单核镍 (II) 配合物的三种分子催化剂，[BzPy] 2 [Ni(mnt) 2 ] ( 1 )、[BzPy] 2 [Ni(i-mnt) 2 ] ( 2 ) 和 [ BzPy] 2 [Ni(tdas) 2 ] ( 3 ) (BzPy = 苄基吡啶) 由 NiCl 2 ∙6H 2 O、[BzPy]Br 和 Na 2 (mnt)/Na 2 (i-mnt ) 反应合成)/Na 2 (tdas) (mnt = ( 1 ) 的 1,2-二氰基乙烯-1,2-二硫醇盐，i-mnt = ( 2的 2,2-二氰基乙烯-1,1-二硫醇盐) 和 tdas = 1,2,5-噻二唑-3,4-二硫醇盐 ( 3 ))。通过XRD、元素分析、FT-IR和ESI-MS对这三种催化剂的结构和组成进行了表征。通过循环伏安法研究了这三种催化剂的电化学性能和相应的催化活性。采用气相色谱分析的可控电位电解证实，在乙腈中 - 0.99 V（相对于 SHE）的电势下，每小时每摩尔催化剂的转换频率 (TOF) 为 116.89、165.51 和 189.16 摩尔 H 2的氢气产生分别含有催化剂的溶液。在中性缓冲溶液中，这三种分子催化剂的 TOF 分别为 411.85、488.76 和 555.06 mol H 2每摩尔催化剂每小时在 - 0.49 V（相对于 SHE）的电位下，分别表明配合物3构成比配合物1和2更好的活性催化剂。为了基本理解，还提出了催化 HER 机制。
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