As important industrial materials, microporous zeolites are necessarily synthesized in the presence of solvents such as in hydrothermal, solvothermal, and ionothermal routes. We demonstrate here a simple and generalized solvent-free route for synthesizing various types of zeolites by mixing, grinding, and heating solid raw materials. Compared with conventional hydrothermal route, the avoidance of solvents in the synthesis not only significantly reduces the waste production, but also greatly increases the yield of zeolite products. In addition, the use of starting solid raw materials remarkably enhances the synthesis efficiency and reduces the use of raw materials, energy, and costs.

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As a typical run, organotemplate-free synthesis of Beta zeolite from a starting aluminosilicate gel with a molar ratio of 40SiO 2 /1Al 2 O 3 /10Na 2 O/570H 2 O at temperature of 140 °C was in the following: (1) 0.12 g of NaAlO 2 and 0.36 g of NaOH was dissolved in 5.1 ml of

Low-cost copper-amine complex was rationally designed to be a novel template for one-pot synthesis of Cu-SSZ-13 zeolites. Proper confirmation and appropriate size make this complex fit well with CHA cages as an efficient template. The products exhibit superior catalytic performance on NH(3)-SCR reaction.

The aims of this study were two-fold: (1) to improve our understanding of the thermal stability of per- and polyfluoroalkyl substances and (2) to investigate their decomposition mechanisms on spent granular activated carbon (GAC) during thermal reactivation. We studied seven perfluoroalkyl carboxylic acids (PFCAs), three perfluoroalkyl sulfonic acids (PFSAs), and one perfluoroalkyl ether carboxylic acid (PFECA) in different atmospheres (N2, O2, CO2, and air). The destabilization of studied compounds during thermal treatment followed first-order kinetics. The temperature needed for thermally destabilizing PFCAs increased with the number of perfluorinated carbons (n CF2). Decomposition of PFCAs such as perfluorooctanoic acid (PFOA) on GAC initiated at temperatures as low as 200 °C. The PFECA was even more readily decomposed than PFCA with the same n CF2. PFSAs such as perfluorooctanesulfonic acid (PFOS), on the other hand, required a much higher temperature (≥450 °C) to decompose. Volatile organofluorine species were the main thermal decomposition product of PFOA and PFOS at low to moderate temperatures (≤600 °C). Efficient mineralization to fluoride ions (>80%) of PFOA and PFOS on GAC occurred at 700 °C or higher, accompanied by near complete PFOA and PFOS decomposition (>99.9%). Thermal decomposition pathways of PFOA were proposed.