High-performance VOx on SrO-γAl2O3 catalyst for oxidative cracking of n-hexane to light olefins under anaerobic environment

Synthesis of bimetallic oxides (SrO-CoO) nanoparticles decorated polyacrylamide hydrogels for controlled drug release and wound healing applications

Hydrogels are polymeric structures characterized by their three-dimensional nature, insolubility in aqueous media, and remarkable ability to absorb significant amounts of water. Owing to their exceptional biocompatibility with living tissues, hydrogels find extensive use in various biomedical applications. Guggul gum grafted polyacrylamide hydrogels (SG) were prepared and green synthesized SrO, CoO and SrO-CoO nanoparticles (NPs) were incorporated with hydrogels (SrG, CoG, Sr-CoG) respectively. The fabricated hydrogels were characterized by various analytical techniques such as FTIR, XRD and SEM. XRD results confirmed the presence of Sr and Co metal nanoparticles in the fabricated hydrogels matrix, SrG pattern showed diffraction peaks at 2θ = 30°, 36.59°, 44.11°, 50.22° and 62.20° while CoG peaks appeared at 2θ = 36.59°, 42.32°, 61.18°, 74.05° and 77.08°. SG, SrG, CoG and Sr-CoG hydrogels showed 11%, 32%, 23% and 45% radical scavenging activity respectively as compared to standard BHT (Butylated hydroxyl toluene). In vitro drug release tests results showed that SG, SrG, CoG and Sr-CoG exhibited 21%, 16%, 13% and 10% sustained release of naproxen respectively. The results revealed that SrO and CoO nanoparticles dopped hydrogels possessed good wound healing potential as compared to conventional hydrogels, which provides great potential in clinical treatment for wounds.

Naphtha catalytic cracking to olefins over zirconia–titania catalyst

A zirconia–titania-based catalyst was synthesized by a co-participation method to study the catalytic cracking of heavy naphtha (dodecane) into high value-added olefins.

Kinetics of Oxidative Cracking of n-Hexane to Light Olefins using Lattice Oxygen of a VOx /SrO-γAl2 O3 Catalyst

The kinetics of oxidative cracking of n-hexane to light olefins using the lattice oxygen of VO_x /SrO-γAl₂ O₃ catalysts has been investigated. Kinetic experiments were conducted in a CREC Riser Simulator (CERC: Chemical Reactor Engineering Center), which mimics fluidized bed reactors. The catalyst's performance is partly attributed to the moderate interaction between active VO_x species and the SrO-γAl₂ O₃ support. This moderate interaction serves to control the release of lattice oxygen to curtail deep oxidation. The incorporation of basic SrO component in the support also helped to moderate the catalyst's acidity to checkmate excessive cracking. Langmuir-Hinshelwood model was applied to formulate the rate equations. The intrinsic kinetic parameters were obtained by fitting the experimental data to the kinetic model using a nonlinear regression algorithm at a 95% confidence interval, implemented in MATLAB. n-Hexane transforms to olefins at a specific reaction rate of 1.33 mol/gcat.s and activation energy of 119.2 kJ/mol. These values when compared with other duplets (i. e., ki° and E_A ) for paraffins to olefins, show that indeed olefins are stable products of the oxidative conversion of n-hexane over VO_x /SrO-γAl₂ O₃ under a fluidized bed condition. Values of activation energy for all CO_x formation routes indicate that intermediate paraffins are likely to be cracked to form CH₄ than to be converted directly to CO_x . On the other hand, olefins may transform partly, and directly to CO_x (E₉ =9.65 kJ/mol) than to form CH₄ (E₈ =89.1 kJ/mol) in the presence of excess lattice oxygen. Overall, olefins appear to be stable to deep oxidation due to the role of SrO in controlling the amount of lattice oxygen of the catalyst at the reaction temperature.