A heteropoly molybdoselenite complex （NH4）6[ Se2Mo8O31 ]·5H2O and its lanthanide salts Ln2 [Se2Mo8O31]-XH2O（Ln = La^3＋, Ce^3＋, Nd^3＋ Sm^3＋） were synthesized and characterized with elemental analysis, IR, ...A heteropoly molybdoselenite complex （NH4）6[ Se2Mo8O31 ]·5H2O and its lanthanide salts Ln2 [Se2Mo8O31]-XH2O（Ln = La^3＋, Ce^3＋, Nd^3＋ Sm^3＋） were synthesized and characterized with elemental analysis, IR, UV, XRD and TG-DTA. Their reactivity for hydroxylation of phenol was investigated. The results show that catalytic activity of （ NH4 ）6 [Se2Mo8O31 ]·5H2O is higher than that of its lanthanide salts. The reaction temperatures, the reaction time. the catalvst amount, the ratio of phenol and H2O2 have influence on the phenol conversation, H2O2 selectivity and product distribution. The optimum reaction condition was obtained with orthogonal method. At optimum reaction condition which the ratio of phenol and H2O2 = 1 ： 1, reaction time is 4 h, reaction temperatures is 70℃ and catalyst is 10 g·mol^-1, and the conversation of phenol reaches as high as 29.65 %, the product selectivity can reach 77.2 % for catalyst （NH4）6[ Se2Mo8O31 ]·5H2O.展开更多
文摘A heteropoly molybdoselenite complex （NH4）6[ Se2Mo8O31 ]·5H2O and its lanthanide salts Ln2 [Se2Mo8O31]-XH2O（Ln = La^3＋, Ce^3＋, Nd^3＋ Sm^3＋） were synthesized and characterized with elemental analysis, IR, UV, XRD and TG-DTA. Their reactivity for hydroxylation of phenol was investigated. The results show that catalytic activity of （ NH4 ）6 [Se2Mo8O31 ]·5H2O is higher than that of its lanthanide salts. The reaction temperatures, the reaction time. the catalvst amount, the ratio of phenol and H2O2 have influence on the phenol conversation, H2O2 selectivity and product distribution. The optimum reaction condition was obtained with orthogonal method. At optimum reaction condition which the ratio of phenol and H2O2 = 1 ： 1, reaction time is 4 h, reaction temperatures is 70℃ and catalyst is 10 g·mol^-1, and the conversation of phenol reaches as high as 29.65 %, the product selectivity can reach 77.2 % for catalyst （NH4）6[ Se2Mo8O31 ]·5H2O.
