Manipulating interstitial carbon atoms in the nickel octahedral site for highly efficient hydrogenation of alkyne.

Light elements in the interstitial site of transition metals have strong influence on heterogeneous catalysis via either expression of surface structures or even direct participation into reaction. Interstitial atoms are generally metastable with a strong environmental dependence, setting up giant challenges in controlling of heterogeneous catalysis. Herein, we show that the desired carbon atoms can be manipulated within nickel (Ni) lattice for improving the selectivity in acetylene hydrogenation reaction. The radius of octahedral space of Ni is expanded from 0.517 to 0.524 A via formation of Ni3Zn, affording the dissociated carbon atoms to readily dissolve and diffuse at mild temperatures. Such incorporated carbon atoms coordinate with the surrounding Ni atoms for generation of Ni3ZnC0.7 and thereof inhibit the formation of subsurface hydrogen structures. Thus, the selectivity and stability are dramatically improved, as it enables suppressing the pathway of ethylene hydrogenation and restraining the accumulation of carbonaceous species on surface. Design and synthesis of non-noble metal catalysts is crucial for highly-efficient hydrogenation. Here, the interstitial sites in nickel are manipulated with zinc and filled by dissociated carbon atoms, which drastically improve the selectivity/stability in acetylene hydrogenation reaction.