The Co@NC catalyst exhibits significant protic solvent preference for hydrogenation of nitriles to primary amines. However, the effect of mixed protic solvents on catalytic hydrogenation has received little attention. Herein, the synergetic solvent effect has been proposed to accelerate the hydrogenation of adiponitrile (ADN) to hexamethylenediamine through H2O‐ethanol hydrogen bond networks on Co@NC catalyst. Experimental screenings on solvents showed that ADN conversion in H2O‐ethanol was 1.6 ~ 5.1 times greater than in single solvents. Kinetic models in H2O/ethanol (vW = 0.6), H2O, and ethanol showed that the solvents effected on H2 transformation dominated the reaction. Isotope labelling and kinetic experiments revealed that H2O and ethanol acted as co‐catalysts through exchanging and transferring hydrogen via hydroxyl groups. Density functional theory calculations confirmed that the energy barrier for proton transfer mediated by H₂O–ethanol was reduced by 0.18 eV compared to proton transfer mediated by H₂O–H₂O dimers.

中文翻译：

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深入了解 H2O-乙醇对己二腈加氢的协同溶剂效应


Co@NC催化剂对腈氢化为主胺表现出显著的质子溶剂偏好。然而，混合质子溶剂对催化加氢的影响很少受到关注。在此，已经提出了协同溶剂效应，以加速己二腈 （ADN） 通过催化剂上的 H2O-乙醇氢键网络Co@NC乙酰二胺。对溶剂的实验筛选表明，己二腈在H2O-乙醇中的转化率是单一溶剂的1.6~5.1倍。H 2 O / 乙醇 （vW = 0.6） 、 H 2 O 和乙醇中的动力学模型表明，影响 H 2 转化的溶剂在反应中占主导地位。同位素标记和动力学实验表明，H2O 和乙醇通过羟基交换和转移氢作为助催化剂。密度泛函理论计算证实，与 H₂O-H₂O 二聚体介导的质子转移相比，H₂O-乙醇介导的质子转移的能垒降低了 0.18 eV。