Transition metal-modified polyoxometalates supported on carbon as catalyst in 2-

ROMINA FRENZEL; GUSTAVO P. ROMANELLI; MIRTA N. BLANCO; LUIS R. PIZZIO

journal of chemical sciences

Springer

Lugar: Bangalore; Año: 2015 vol. 127 p. 123 - 132

0974-3626

Polyoxometalates with lacunary Keggin structure modified with transition metal ions[PW11O39M(H2O)]5-, where M= Ni2+, Co2+, Cu2+or Zn2+, were synthesized andsupported on activated carbon to obtain the PW11MC catalysts. By FT-IR and DTATGAit was concluded that the [PW11O39M(H2O)]5- species are interacting with thefunctional groups of the support, and that the thermal treatment leads to the loss of thecoordinatively bonded water molecules, without any noticeable anion degradation. Theactivity and selectivity of the catalysts in the sulfoxidation reaction of 2-(methylthio)-benzothiazole, an emerging environmental pollutant, were evaluated. The reaction wascarried out in acetonitrile as solvent using H2O2 35% p/v as a clean oxidant. Theconversion values decreased in the following order: PW11NiC > PW11CuC >PW11CoC > PW11ZnC, with selectivities to sulfoxide higher than 69%. The catalystcould be reused without appreciable loss of the catalytic activity at least three times.The materials were found to be efficient and recyclable catalysts for 2-(methylthio)-benzothiazole sulfoxidation in order to obtain a more biodegradable product than thecorresponding substrate.