Pakiza Begum

A Comparative DFT Study on the Catalytic Oxidation of Nitric Oxide by Pd2 and PdM (M = Cu, Rh, Ag, Au, Pt)

AbstractA detailed mechanistic investigation for the catalytic oxidation of NO over monometallic palladium dimer and its bimetallic counterparts, PdM (M = Cu, Rh, Ag, Au, Pt) has been performed using DFT. Nitric oxide is a major environmental problem, inclusive of acid rain and photochemical smog formation which is released mainly in automobile exhausts. Thus, removal of poisonous NO is a major challenge and understanding its oxidation at molecular level is of great importance in designing suitable catalysts. Bimetallic nanoparticles are more promising as catalyst due to synergetic effect. A full catalytic cycle has been studied producing two NO2 molecules from two molecules of NO and one O2 molecule. Both the pristine and bimetallic systems catalyse the reaction according to Eley–Rideal mechanism. The bimetallic PdCu system is found to be the most dominant catalytic system with the more active Pd-site (i.e. O2 activated by Pd-site). The present study enlightens the understanding for higher catalytic activity of bimetallic nanoparticle.Graphical AbstractDFT studies for the catalytic oxidation of NO on pure and bimetallic palladium clusters: Pd2, PdAu, PdAg, PdRh, PdCu, and PdPt. Removal of poisonous NO is a major challenge and understanding its oxidation at molecular level is of great importance in designing suitable catalysts. A full catalytic cycle has been studied producing two NO2 molecules from two NO molecules in presence of air. Energetic calculation reveals that PdCu is the predominant catalytic system with more active Pd-site.

Property enhancement and DFT study of wood polymer composites using rosin derivatives as co-monomers

We report herein the preparation of wood polymer composites with modified soybean oil as the polymer matrix and softwood as the reinforcement agent. This study concentrates on the possibility to replace styrene with rosin-based derivatives as the rigid monomer, in order to improve the performance of the final composite. For comparison, styrene was also used to co-polymerize with the modified soybean oil. The chemical structures of the synthesized rosin derivatives were confirmed by Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopy. The mechanical and thermal properties showed significant improvement after co-polymerization with rosin derivatives. The probable interaction among the polymer matrix, rosin derivative and wood flour was established by FTIR analysis, also supported by Density Functional Theory (DFT) calculations. The surface morphology, water uptake capacity, volumetric swelling and flame retarding properties of the composites were investigated. The results demonstrate that rosin acid derivatives possess great potential as co-monomers to replace petroleum-based rigid compounds for the preparation of soybean oil based wood polymer composites.