High Surface Area Mesoporous GaPO4–SiO2 Sol–Gel Glasses: Structural Investigation by Advanced Solid-State NMR

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• 作者：Jinjun Ren ; Carsten Doerenkamp ; Hellmut Eckert
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：January 28, 2016
• 年：2016
• 卷：120
• 期：3
• 页码：1758-1769
• 全文大小：649K
• ISSN：1932-7455

文摘

Mesoporous silica–gallium phosphate glasses along the composition line, xGaPO<sub>4sub>–(1 – x)SiO<sub>2sub> (x = 0.5, 0.33, 0.20, 0.14, and 0.11, respectively) were prepared via the sol–gel route. This glass-forming range is significantly wider than that accessible by previously reported routes. The glasses exhibit a mesoporous structure with surface areas around 400 m<sup>2sup>/g, after calcination at 650 °C. The structural evolution from liquid to gel to glass was analyzed by liquid and advanced solid-state nuclear magnetic resonance techniques. The NMR results indicate that the glasses consist of GaPO<sub>4sub> and SiO<sub>2sub> nanodomains. With increasing GaPO<sub>4sub> content, the sizes of the GaPO<sub>4sub> domains become larger. Evidence for the connection of both domains at their interfaces by P–O–Si and Ga–O–Si linkages is presented by advanced <sup>71sup>Ga, <sup>31sup>P, and <sup>29sup>Si high-resolution dipolar solid-state NMR methods.