Nickel is a highly active catalyst for the semi-hydrogenation of alkynes. However, the low selectivity of the alkene product caused by the over-hydrogenation reaction on Ni has hindered its practical applications. In this work, we report a new nickel nitride (Ni₃N)-catalyzed semi-hydrogenation of alkynes to the corresponding alkenes. The Ni₃N nanorods were facilely fabricated via a direct pyrolysis of the solid mixture of nickel acetate tetrahydrate and melamine (Mlm). The Ni₃N phase in the optimum catalyst (Ni₃N/NC-6/5-550) is shown to be effective and stable in the semi-hydrogenation of alkynes, with a high yield and good selectivity for alkenes (Z/E ratios up to >99/1). Both terminal and internal alkynes bearing a broad scope of functional groups are readily converted into alkenes with good chemo- and stereoselectivity. Notably, it was found that the over-hydrogenation can be markedly suppressed even at high conversion of alkyne. Density functional theory (DFT) calculations reveal that the low interaction between the alkene product and the Ni₃N might plays a critical role in the selectivity enhancement.

镍是用于炔烃半加氢的高活性催化剂。但是，由于Ni上的过度氢化反应所引起的烯烃产物的低选择性阻碍了其实际应用。在这项工作中，我们报告了一种新的氮化镍（Ni ₃ N）催化的炔烃半氢化成相应的烯烃。Ni ₃ N纳米棒是通过将四水合醋酸镍和三聚氰胺（Mlm）的固体混合物直接热解而容易地制备的。研究表明，最佳催化剂（Ni ₃ N / NC-6 / 5-550）中的Ni ₃ N相在炔烃的半加氢中是有效和稳定的，具有高收率和对烯烃的良好选择性（Z / E比率高达> 99/1）。带有广泛范围的官能团的末端炔烃和内部炔烃都易于转化为具有良好的化学和立体选择性的烯烃。值得注意的是，发现即使在炔烃的高转化率下也可以显着抑制过氢化。密度泛函理论（DFT）计算表明，烯烃产物与Ni ₃ N之间的低相互作用可能在选择性提高中起关键作用。