物理化学学报2001，Vol.17Issue(5)：443-447,5.
ZrO2表面 B2O3的分散及其作用状态
Dispersion and Interaction State of Boria on Zirconia Surface
摘要
Abstract
Dispersion of B2O3 on zirconia surface with load levels up to 20％ B2O3 was explored with samples that were prepared by impregnation of boric acid onto porous ZrO2 obtained by precalcination of ZrO(OH)2 at different temperatures (110－ 700 ℃ ). After calcination at 350 ℃ , the B2O3/ZrO2 samples were characterized with FT-IR, XPS and FT-Raman techniques to determine the interaction state of B2O3 on the surface. Both tetrahedral BO4 and trigonal BO3 were detected as the basic units of the dispersed B2O3. The ratio of BO4 to BO3 units depended strongly on the temperature of the precalcination and the load level of boria. At lower precalcination temperature for the support and at low levels of boria load, B2O3 interacts directly with the support surface in BO4 units and forms monolayer dispersion. Inversely,multilayer dispersion with BO3 as the structural unit forms over the support precalcined at high temperature. The XPS and Raman data also provide good measurements for monolayer dispersion capacity of boria; with ZrO2 precalcined at 500 ℃ , this capacity is 0.05 g/g(or mass fraction of B2O3 w=4.7 6 ％ ). A model for the dispersion structure of B2O3/ZrO2 has been proposed.关键词
B2O3,ZrO2,表面作用,分散阈值分类
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徐柏庆,程时标..ZrO2表面 B2O3的分散及其作用状态[J].物理化学学报,2001,17(5):443-447,5.
