Double-Heterostructured Nickel Phosphate-Phosphides as High-Activity Electrocatalyst for Ammonia Borane Electrooxidation

The direct electrooxidation reaction of ammonia borane (ABOR) as the anodic reaction of direct ammonia borane fuel cells (DABFCs) is greatly dependent on the properties of electrocatalysts. Both the active sites and charge/mass transfer characteristics are the key to promoting the processes of kinetics and thermodynamics, which can further improve the electrocatalytic activity. Hence, the catalyst double-heterostructured Ni₂P/Ni₂P₂O₇/Ni₁₂P₅ (d-NPO/NP) with the optimistic redistribution of electrons and active sites is prepared for the first time. The d-NPO/NP-750 catalyst obtained after pyrolysis at 750 °C shows the outstanding electrocatalytic activity toward ABOR with an onset potential of −0.329 V vs RHE which is better than all the published catalysts. The density functional theory (DFT) computations illustrate that the Ni₂P₂O₇/Ni₂P acts as the activity enhancement heterostructure with a high d-band center (−1.60 eV) and the low activation energy barrier, while the Ni₂P₂O₇/Ni₁₂P₅ acts as the conductivity enhancement heterostructure with the highest density of valence electrons.     

油脂氢化三元金属催化剂制备及性能研究(II)--制备条件的研究

本文在金属元素和组成固定的条件下,利用正交实验研究了催化剂的制备条件(沉淀温度A、老化平衡时间B、干燥温度C、加料方式D)对大豆油加氢催化剂活性与选择性的影响,发现影响催化剂活性的顺序是D>A>B>C,影响亚麻酸选择性指数SⅡ的顺序是A>B>D>C,亚油酸选择性指数SⅠ的顺序是B>A>C>D,其最佳制备条件是沉淀温度70℃,老化平衡时间40min,干燥温度105℃,加料方式为并加法.并利用线性回归方法建立了大豆油氢化时亚麻酸与亚油酸的选择性指数SⅡ和SⅠ与主要制备条件(A/K、B/min 、C/K)之间的关系,即 SⅡ=-2.6386+0.0104A+0.0055B+0.003133C SⅠ=0.1607+0.0008A+0.00189B+0.0053C