Hybrid NaLTA/PDMS composites were produced by dispersing NaLTA zeolite synthesized from calcined kaolin into a polydimethylsiloxane (PDMS) silicone rubber matrix, followed by molding and room-temperature vulcanization to obtain pellet-shaped adsorbents for application in CO2/N2 gas separation. Pellet-shaped composites containing different zeolite loadings were prepared and characterized by XRD, FTIR, and SEM analyses. XRD results confirmed the formation of crystalline NaLTA zeolite and indicated the absence of structural changes after adsorption, suggesting a predominantly physisorption process. FTIR spectra demonstrated the successful incorporation of zeolite into the PDMS matrix, while SEM images revealed homogeneous dispersion and favorable interfacial interaction between the inorganic filler and the polymeric phase. Sorption analyses showed that increasing zeolite loading enhanced CO2 adsorption capacity, with the composite containing 44 wt% zeolite exhibiting the best overall performance. This material reached a CO2/N2 selectivity of 58.5 at 1000 mmHg, surpassing values reported for similar zeolite/PDMS systems. Cyclic sorption experiments also demonstrated stable adsorption behavior after consecutive CO2 and N2 adsorption steps, indicating the potential applicability of the composite in cyclic gas separation processes.
The Prins reaction of indene with paraldehyde affords 4,4a,5,9b-tetrahydro-2,4-dimethylindeno[1,2-d]-1,3-dioxin, a compound possessing desirable fragrance characteristics and reported biological activity. The present study investigates the applicability of commercially available zeolites as heterogeneous catalysts for this transformation. A broad range of zeolite materials, including Beta, Y, and ZSM-5 types, was evaluated with respect to catalytic activity, indene conversion, and product selectivity. Among the tested catalysts, the ultrastable Y zeolite (USY) exhibited the best performance, achieving an indene conversion of 96
We report a study of the electrochemical performances of polyethylene glycol 400 (PEG400)-mediated synthesis of Pb nanoparticles supported on carbon black (np-Pb/CB). The synthesis was conducted in air at normal pressure evaluate. To evaluate this formulation, graphite rods were employed as substrate. The influence of synthesis temperature on the structural, compositional, and electrocatalytic properties of the resulting np-Pb/CB-based cathodes were investigated. PEG400 and 170 degrees C were identified as the optimal synthesis conditions, yielding well-dispersed spherical nanoparticles and the most homogeneous surface coverage on the carbon support and when operated at -1.4 V vs. Ag/AgCl deliver the highest and most stable cathodic current density, corresponding to an overpotential (eta) of approximately 103 mV. These findings highlight PEG400 for tailoring nanoparticles surface properties toward selective CO2 to formate production.
Herein, Ru-doped V2O5-WO3/TiO2 (VWTi) catalysts were prepared to study the impact of Ru doping on chlorobenzene (CB) oxidation activity. The introduction of Ru weakens the V-O bond strength, resulting in neutralizing the Lewis acid effect and optimizing the overall acid balance of the VWTi catalyst. Moreover, the presence of RuO2 can significantly enhance the redox capability and surface lattice oxygen mobility. Hence, a significant improvement in both low-temperature activity and CO2 selectivity has been achieved with the Ru-doped VWTi catalyst, reaching a CB conversion of 50% at 205 degrees C and a CO2 selectivity of 73% at 400 degrees C for 0.50Ru-VWTi catalyst.
Pine wood pyrolysis was investigated at slow heating rates of 10–35 K/min and fast heating rates of 150–350 K/min using thermogravimetric analysis coupled with FTIR-MS product analysis. Increasing heating rate shifted the DTG shoulder temperature from 622 to 712 K, the main DTG peak temperature from 653 to 752 K, and the temperature corresponding to a fixed conversion of α=0.85 from 669.6 to 763.9 K, while the final residual mass remained within 18.3–19.8
