Molten Salt Synthesis of Intermetallic Compound TiNi Nanopowder Passivated by TiOx Shell Prepared from NiTiO3 for Catalytic Hydrogenation

Abstract

Titanium-nickel alloy is an attractive material due to its unique properties of shape memory effect, superior elasticity, and biocompatibility. Generally, Ti-Ni alloy powders are prepared from pure elemental powders of Ti and Ni as starting materials, but it is an energy-intensive process to obtain pure titanium. In this study, intermetallic compound TiNi powder passivated by TiOx shell was prepared by directly reducing a commercial NiTiO3 using CaH2 reducing agent in a molten LiCl at 650 °C. Analyses by X-ray diffraction, scanning electron microscopy/transmission electron microscopy with energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy revealed that the powder had a core–shell structure, with the core of TiNi and the shell of TiOx-rich composition with scarce metallic Ni nicely catalyzing hydrogenation reactions with good recyclability and stability.

CaH2-Assisted Molten Salt Synthesis of Zinc-Rich Intermetallic Compounds of RhZn13 and Pt3Zn10 for Catalytic Selective Hydrogenation Application

“…Molten salt synthesis is a good technique to obtain active catalysts [9][10][11][12]. Previously, we prepared some nanosized intermetallic compounds using the CaH 2 -assisted molten salt synthesis [13] and exhibited that some are available as good catalyst supports, such as Ti 6 Si 7 Ni 16 [14], and some are active species, such as TiNi [15], YIr 2 [16], CaPt 2 [17]. In a reduction condition with a CaH 2 reducing agent in a molten LiCl-KCl at 360 • C, ZnO was totally reduced to metallic zinc to alloy with metallic Ni, following a formation of intermetallic compound NiZn [18].…”