Aqueous stability of alumina and silica perhydrate hydrogels: experiments and computations

作者：Wolanov Yitzhak; Shurki Avital^*; Prikhodchenko Petr V; Tripol'skaya Tatiana A; Novotortsev Vladimir M; Pedahzur Rami; Lev Ovadia

来源：Dalton Transactions, 2014, 43(44): 16614-16625.

DOI：10.1039/c4dt01024h

Alumina and silica perhydrate hydrogels were synthesized. Raman spectroscopy and solid Al-27 MAS NMR confirmed alumina perhydrate formation. Thermal and aqueous stability of alumina and silica perhydrates was studied, and they showed exceptionally high stabilities. Alumina perhydrate retained some of the hydrogen peroxide even at 170 degrees C, higher than any other reported perhydrate, whereas the silica perhydrate lost its hydrogen peroxide content already at 90 degrees C. The silica perhydrate lost all its peroxide content upon immersion in water, whereas the alumina perhydrate was stable under near-neutral pH conditions. A computational study was conducted in order to glean molecular insight into the observed thermal and aqueous stability of alumina compared to silica perhydrate. Comparison of the hydrogen bond features and the stabilization energies of the hydrate and perhydrate of silica and alumina revealed a higher preference for hydrogen peroxide over water by alumina relative to silica. This is shown to be due to hydrogen peroxide being a better hydrogen donor than water and due to the superior hydrogen accepting propensity of alumina compared to silica.

• 出版日期2014
• 单位中国科学院长春应用化学研究所