The catalytic oxidation of gaseous HCl (containing a small amount of HF) to Cl 2 is important and highly desired for chlorine recycling in the fluorochemical industry. In the present work, a series of Al-doped MgF 2 (Al− MgF 2 ) materials were synthesized via a sol−gel method, followed by calcination at different temperatures and then these synthesized Al−MgF 2 materials were used as supports to prepare RuO 2 /Al−MgF 2 catalysts by an incipient impregnation method. These developed catalysts were evaluated in the oxidation of HCl with an upper-bound HF concentration of 400 ppm, as is common in the fluorochemical industry. Specific attention was paid to investigating the effects of calcination temperature for preparing Al−MgF 2 supports on the activity and stability of the resultant catalysts. It is found that at an optimal calcination temperature, Al can be incorporated into the framework of rutile structure MgF 2 , which can further modify the cell parameters of MgF 2 close to those of RuO 2 , modulate the interactions between RuO 2 and the support, and yet affect the chemical environment of RuO 2 to enhance the catalytic activity and stability. The study on the catalytic kinetics reveals that the estimated apparent activation energy is in line with the incorporated amount of Al into the framework of MgF 2 and shows an inverted volcano relationship with the calcination temperature for preparing Al−MgF 2 supports. The lowest apparent activation energy of RuO 2 /Al−MgF 2 can be achieved when the Al−MgF 2 composite is calcined at 400 °C, and the resultant catalyst shows long-term stability with high activity for the oxidation of HCl containing a small amount of HF.

The component fluxes and separation factors of the two binary systems CO2/CH4 and n-butane/isobutane through a defect-free silicalite-1 membrane were measured and modeled by the generalized Maxwell-Stefan (GMS) equations. For a mixture of CO2 and CH4 through the zeolite membrane, the GMS equations in combination with the Ideal Adsorbed Solution (IAS) theory for the mixture adsorption appropriately describe the component fluxes. On the other hand, this model cannot predict the permeation behavior of a mixture of butane isomers. In the current study, the proposed model based on the GMS equations combined with the Binary Dual-site Langmuir (BDSL) for the adsorption of butane isomers on silicalite-1 successfully simulates the permeation fluxes and separation factors.

A facile protocol was developed to synthesize pure DD3R crystals with a controllable morphology and size, as well as high reproducibility and productivity.