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Polyhedron lead hydroxide carbonate(2PbCO3·Pb(OH)2) microcrystals have been prepared in solution phase via a facile method in the presence of surfactant cetyltrimethylammonium bromide(CTAB).All the samples were characterized by powder X-ray diffraction pattern(XRD),field-emission scanning electron microscopy(FE-SEM),high-resolution transmission electron microscopy(HRTEM),and selected area electron diffraction(SAED).The possible growth mechanism was discussed.2PbCO3·Pb(OH)2 microcrystals were found to be a novel and efficient catalyst for the synthesis of diphenyl carbonate(DPC) by transesterification of dimethyl carbonate(DMC) with phenol.Compared with some other catalysts,such as AlCl3,ZnCl2,and Mg5(CO3)4(OH)2,2PbCO3·Pb(OH)2 microcrystals are stable and show relatively high activity at low catalyst amount.When the reaction was carried out at 180 ℃,with a molar ratio of phenol to DMC of 2:1,a reaction time 14 h,and a catalyst amount 0.2%(molar ratio to phenol),the selectivity of DPC and methyl phenyl carbonate(MPC) was 14.7% and 78.8%,respectively.
Polyhedron lead hydroxide carbonate (2PbCO 3 · Pb (OH) 2) microcrystals have been prepared in solution phase via a facile method in the presence of surfactant cetyltrimethylammonium bromide (CTAB). All the samples were characterized by powder X-ray diffraction pattern , field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). Possible growth mechanism was discussed. PbP (OH) 2 microcrystals were found to be a novel and efficient catalyst for the synthesis of diphenyl carbonate (DPC) by transesterification of dimethyl carbonate (DMC) with phenol. Compared with some other catalysts such as AlCl3, ZnCl2, and Mg5 (CO3) 4 Pb (OH) 2 microcrystals are stable and show relatively high activity at low catalyst amount. When the reaction was carried out at 180 ° C, with a molar ratio of phenol to DMC of 2: 1, a reaction time 14 h, and a catalyst amount 0.2% (molar ratio to phenol), the selectivity of D PC and methyl phenyl carbonate (MPC) was 14.7% and 78.8% respectively.