Zr-/Ce-/Sm-containing intermetallic compounds, specifically ZrZnNi4, CeNi5, CeAlNi4, CeNi4Si, Ce(NiSi)2, SmNi3, SmNi4Si, and Sm(NiSi)2, were synthesized by reducing the metal oxides using a CaH2 reducing agent within molten LiCl. The resultant nanopowders exhibited high specific surface areas: ZrZnNi4 (42.0 m2 g-1), CeAlNi4 (66.9 m2 g-1), and Sm(NiSi)2 (25.0 m2 g-1). They were subsequently tested for their effectiveness in the NaBH4-assisted hydrogenation of 4-nitrophenol. When compared to the prepared catalysts, including a conventional CeO2-supported Ni catalyst, ZrZnNi4 demonstrated the highest catalytic activity. Based on experimental results and density functional theory calculations, it was proposed that enhanced performance could be attributed to the formation of electron-rich Ni species in ZrZnNi4.
Kobayashi et al. (Thu,) studied this question.