Differential Selectivity of Palladium–Phosphorus Catalysts in the Competitive Hydrogenation of Isomeric Chloronitrobenzenes

The competitive hydrogenation of сhloronitrobenzene isomers in the presence of different palladium- containing catalysts was studied. The nature of catalytic activity carriers for the Pd–P nanoparticles containing both Pd(0) clusters and palladium phosphides was determined by the method of phase trajectories. It was found that the hydrogenation of сhloronitrobenzene isomers under mild conditions occurred on the clusters of Pd(0), and the dependence of the differential selectivity of Pd–P clusters in the hydrogenation of o- and m-сhloronitrobenzene on the P/Pd ratio was related to the dispersity of the Pd(0) clusters.     

Pyrimidine-containing poly[bis(itaconimides)]

Heat-resistant pyrimidine-containing poly[bis(itaconimides)] with a glass transition temperature of 240–250°C were synthesized via the polyaddition reaction. The film materials based on a pyrimidine-containing poly[bis(itaconimide)] and an aromatic polybenzimidazole acquired good electric and mechanical characteristics after doping with phosphoric acid.     

The Effect of Particle Size and the Modifier on the Properties of Palladium Catalysts in the Synthesis of Hydrogen Peroxide by the Anthraquinone Method

The effect of the composition of the catalytic system and the size of particles on the properties of palladium catalysts in 2-ethyl-9,10-anthraquinone hydrogenation was studied. It was shown that, depending on the nature of a reducing agent (H₂, AlEt₃), palladium species formed in the absence of a modifying agent catalyze various side processes to a substantial extent together with 2-ethyl-9,10-anthraquinone hydrogenation: mostly hydrogenolysis (in the case of H₂ as a reducing agent) and hydrogenation of aromatic rings in 2-ethyl-9,10-anthrahydroquinone (in the case of AlEt₃ as a reducing agent). Elementary phosphorus was found to have a promoting effect on the selectivity of palladium catalysts in the synthesis of hydrogen peroxide by the anthraquinone method. The main factors that make it possible to control the selectivity of palladium catalysts were discussed.     

Effect of the State of a Surface Layer on the Properties of Pd–P Catalysts in the Hydrogenation of Alkylanthraquinones

Kinetics and Catalysis - X-ray photoelectron spectroscopy (XPS) was used to study the state of the surface layer of a Pd–P catalyst, which exhibits high selectivity in the hydrogenation of...