High-surface-area mesoporous silica-yttria-zirconia ceramic materials prepared by coprecipitation method ― the role of silicon |
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Affiliation: | 1. Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, 610065, China;2. College of Chemical Engineering, Sichuan University, Chengdu, 610065, China;3. Key Laboratory of Green Chemistry and Technology of the Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610065, China |
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Abstract: | A high surface area is one of desired properties for yttria-zirconia (Y2O3–ZrO2) ceramic materials given their catalytic applications. The objective of this study is to develop high-surface-area Y2O3–ZrO2 materials by silicon (Si) modification and investigate the role of Si. Si-modified yttrium-zirconium hydroxides were prepared via a one-step precipitation process and calcined at 800 or 950 °C to form Si-modified Y2O3–ZrO2 (denoted as SiO2–Y2O3–ZrO2) materials containing 0-20 wt% Si as SiO2. These hydroxides or materials were characterized by 29Si NMR, XPS, TG-DSC, XRD, UV Raman, TEM, and N2 physisorption measurements. Si species uniformly distributed in the hydroxides tended to be enriched on the material surface at high temperatures. These Si species dominated by the silicates blocked the migration of Y and Zr atoms, which resisted the crystallite growth of Y2O3–ZrO2 components and reduced their crystallite size. Therefore, the SiO2–Y2O3–ZrO2 possessed a surface area of 59-112 m2/g after calcination at 950 °C for 9 h, which was significantly higher than that of the Y2O3–ZrO2 (23 m2/g). This study may stimulate ideas for developing high-surface-area crystalline ceramic materials calcined at high temperatures. |
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Keywords: | Silica-yttria-zirconia Silicate species Crystallite size Specific surface area |
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