Facile Synthesis of Methylsilsesquioxane Aerogels with Uniform Mesopores by Microwave Drying

Methylsilsesquioxane (MSQ) aerogels with uniform mesopores were facilely prepared via a sol–gel process followed by microwave drying with methyltrimethoxysilane (MTMS) as a precursor, hydrochloric acid (HCl) as a catalyst, water and methanol as solvents, hexadecyltrimethylammonium chloride (CTAC) as a surfactant and template, and propylene oxide (PO) as a gelation agent. The microstructure, chemical composition, and pore structures of the resultant MSQ aerogels were investigated in detail to achieve controllable preparation of MSQ aerogels, and the thermal stability of MSQ aerogels was also analyzed. The gelation agent, catalyst, solvent, and microwave power have important roles related to the pore structures of MSQ aerogels. Meanwhile, the microwave drying method was found to not only have a remarkable effect on improving production efficiency, but also to be conducive to avoiding the collapse of pore structure (especially micropores) during drying. The resulting MSQ aerogel microwave-dried at 500 W possessed a specific surface area up to 821 m2/g and a mesopore size of 20 nm, and displayed good thermal stability.

Facile Synthesis of Methylsilsesquioxane Aerogels with Uniform Mesopores by Microwave Drying

Methylsilsesquioxane aerogels with uniform mesopores have been facilely prepared via a sol–gel process followed by microwave drying with methyltrimethoxysilane (MTMS) as precursor, hydrochloric acid (HCl) as catalyst, water and methanol as solvents, hexadecyltrimethylammonium chloride (CTAC) as surfactant and template and propylene oxide (PO) as gelation agent. The microstructure, chemical composition and pore structures of the resultant MSQ aerogels were investigated in detail to achieve controllable preparation of MSQ aerogels, and the thermal stability of MSQ aerogels was also analyzed. The gelation agent, catalyst, solvent and microwave power have important roles on pore structures of MSQ aerogels. Meanwhile, microwave drying method is found to not only have a remarkable effect on improving production efficiency, but also be conducive to avoid the collapse of pore structure especially micropores during drying. The resulting MSQ aerogel microwave-dried at 500 W possesses a specific surface area up to 821 m2/g and a mesopore size of 20 nm, and displays good thermal stability.

The rational synthesis of aerosol-assisted alumina powders having uniform mesopores and highly accessible surfaces

Several important factors to fabricate high-quality aerosol-assisted mesoporous alumina powders are summarized by considering rational and reliable synthetic routes.

Engineering Mesoporous NiO with Enriched Electrophilic Ni3+ and O− toward Efficient Oxygen Evolution

Tremendous efforts have been devoted to develop low-cost and highly active electrocatalysts for oxygen evolution reaction (OER). Here, we report the synthesis of mesoporous nickel oxide by the template method and its application in the title reaction. The as-prepared mesoporous NiO possesses a large surface area, uniform mesopores, and rich surface electrophilic Ni3+ and O− species. The overpotential of meso-NiO in alkaline medium is 132 mV at 10 mA cm−1 and 410 mV at 50 mA cm−1, which is much smaller than that of the other types of NiO samples. The improvement in the OER activity can be ascribed to the synergy of the large surface area and uniform mesopores for better mass transfer and high density of Ni3+ and O− species favoring the nucleophilic attack by OH− to form a NiOOH intermediate. The reaction process and the role of electrophilic Ni3+ and O− were discussed in detail. This results are more conducive to the electrochemical decomposition of water to produce hydrogen fuel as a clean and renewable energy.

Hierarchical ZSM-5 zeolite with uniform mesopores and improved catalytic properties

Uniform mesopores are generated in hierarchical ZSM-5 by a mesopore narrowing treatment, showing enhanced activity in the acylation of 2-methoxynaphthalene.