Nano-size bimetallic ternary hydrogenation catalysts based on nickel and copper complexes

Abstract

The turnover frequencies of multicomponent ternary catalytic systems formed on the basis of Ni(acac)2 and Cu(acac)2 with LiAlH4 at Т = 30 оС and РН2 = 2 atm in styrene hydrogenation were determined. It was shown that, at other things being equal, catalytic activity is defined by the order of mixing of the components at the catalyst formation stage. Namely, three particular cases are considered: sequential reduction of Ni(acac)2 and Cu(acac)2 by LiAlH4 (first Ni(acac)2, then Cu(acac)2 and vice versa) and simultaneous reduction of Ni(acac)2 and Cu(acac)2 with LiAlH4. It has been established that nano-sized structures of the core@shell type act as carriers of catalytic activity. The nano-sized structures are stabilized by the ligand shell, which contain Li(acac) as well as AlH4– and AlH63–-anions. The model of the catalytically active (in styrene hydrogenation) nanoparticle formed by sequential reduction of Cu(acac)2 with LiAlH4 and Ni(acac)2 is presented.