Hydrogenation properties of SrAl₂ alloy doped with Ti-based catalystss

Phase structure, surface morphology, hydrogenation property and catalytic mechanism of the Zintl phase alloy SrAl₂ doped with 2 mol.% Ti-based catalysts (including TiF₃, Ti and TiO₂) were investigated systematically by means of XRD, SEM, EDS, PCT and XPS. It was shown that the three Ti-based catalysts can improve the hydrogenation kinetics of the SrAl₂ alloy, and the catalytic effect followed the order of TiF₃ > Ti > TiO₂. XPS analysis of the alloy before and after hydrogenation indicated that the binding energy of Ti 2p on the alloy surface changed upon hydrogenation. Particularly, Ti⁰ was observed in the TiF₃-doped SrAl₂ alloy. The intermediate product of Ti⁰ has great catalysis on hydrogenation of SrAl₂, and the catalytic effect of Ti⁰ is better than Ti doped initially, leading to the best hydrogenation kinetics of TiF₃-doped SrAl₂ alloy.