Enhancement in the reaction rates in the hydroxylation of aromatics over TS-1/H2O2 under solvent-free triphase conditions

Post-synthesis of MSE-type titanosilicates by interzeolite transformation for selective anisole hydroxylation

MSE-type titanosilicate was efficiently post-synthesized by the combination of interzeolite transformation by siliceous Beta, dealumination and isomorphous substitution of Ti, and it exhibited high catalytic activity in anisole hydroxylation.

Enhanced anisole hydroxylation over a hierarchical micro/mesoporous TS-1 catalyst

Micro/mesoporous DTS-1 showed enhanced catalytic activity for anisole hydroxylation showing 54% conversion with 55% selectivity towards p-methoxyphenol.

Selective synthesis of epichlorohydrin via liquid-phase allyl chloride epoxidation over a modified Ti-MWW zeolite in a continuous slurry bed reactor

The epoxidation of allyl chloride (ALC) to epichlorohydrin (ECH) with H₂O₂ using a piperidine (PI)-modified Ti-MWW catalyst (Ti-MWW-PI) in a continuous slurry reactor was investigated to develop an efficient reaction system for the corresponding industrial process.

Manganese-cerium composite oxide pyrolyzed from metal organic framework supporting palladium nanoparticles for efficient toluene oxidation

Manganese-cerium metal oxide with flocculent structure prepared via the pyrolysis of Mn/Ce-MOF and supported Pd were applied for the catalytic oxidation of toluene. The Pd/Mn3Ce2-300 catalyst could completely oxidize toluene at 190 °C, which presented excellent catalytic performance. Moreover, Pd/Mn3Ce2-300 possessed great reusability, stability and water resistance even under 10 vol% water vapors. A series of characterizations including X-ray diffraction (XRD), N₂ adsorption-desorption, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and H₂ temperature programmed reduction (H₂-TPR) were used to investigate the physicochemical properties of the samples. It was found that Pd/Mn3Ce2-300 possessed a better reduction ability at low temperature, more surface absorbed oxygen and surface Pd species, and a strong interaction between Pd and Mn3Ce2-300, resulting in great catalytic performance for toluene degradation.

Synthesis and catalytic applications of combined zeolitic/mesoporous materials

In the last decade, research concerning nanoporous siliceous materials has been focused on mesoporous materials with intrinsic zeolitic features. These materials are thought to be superior, because they are able to combine (i) the enhanced diffusion and accessibility for larger molecules and viscous fluids typical of mesoporous materials with (ii) the remarkable stability, catalytic activity and selectivity of zeolites. This review gives an overview of the state of the art concerning combined zeolitic/mesoporous materials. Focus is put on the synthesis and the applications of the combined zeolitic/mesoporous materials. The different synthesis approaches and formation mechanisms leading to these materials are comprehensively discussed and compared. Moreover, Ti-containing nanoporous materials as redox catalysts are discussed to illustrate a potential implementation of combined zeolitic/mesoporous materials.

Immersion calorimetry as a tool to evaluate the catalytic performance of titanosilicate materials in the epoxidation of cyclohexene

Different types of titanosilicates are synthesized, structurally characterized, and subsequently catalytically tested in the liquid-phase epoxidation of cyclohexene. The performance of three types of combined zeolitic/mesoporous materials is compared with that of widely studied Ti-grafted-MCM-41 molecular sieve and the TS-1 microporous titanosilicate. The catalytic test results are correlated with the structural characteristics of the different catalysts. Moreover, for the first time, immersion calorimetry with the same substrate molecule as in the catalytic test reaction is applied as an extra means to interpret the catalytic results. A good correlation between catalytic performance and immersion calorimetry results is found. This work points out that the combination of catalytic testing and immersion calorimetry can lead to important insights into the influence of the materials structural characteristics on catalysis. Moreover, the potential of using immersion calorimetry as a screening tool for catalysts in epoxidation reactions is shown.