[1] Romanian Acad, Ilie Murgulescu Inst Phys Chem, 202 Splaiul Independentei, Bucharest 060021, Romania
[2] Alexandru Ioan Cuza Univ, Fac Phys, 11 Carol 1 Blvd, Iasi 700506, Romania
[3] Univ Politehn Bucuresti, Dept Oxide Mat Sci & Engn, 1-7 Gh Polizu, Bucharest 011061, Romania
[4] Natl Res & Dev Inst Ind Ecol, ECOIND, 71-73 Drumul Podu Dambovitei St, Bucharest 060652, Romania
[5] Univ Bucharest, Dept Phys Chem, Fac Chem, 4-12 Bd Regina Elisabeta, Bucharest 0300016, Romania
[6] Alexandru Ioan Cuza Univ, Res Dept, Fac Phys, 11 Carol 1 Blvd, Iasi 700506, Romania
[7] Bulgarian Acad Sci, Inst Catalysis, G Bonchev Str,Bl 11, BU-1113 Sofia, Bulgaria