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P-type Cu2O nanocrystals were deposited on n-type silicon nanowire arrays (Si NWs) to form core-shell heterojunction arrays structure via a simple electroless deposition technique. Scanning electron microscopy, transmission electron microscope and x-ray diffraction were utilized to characterize the morphology and structure of the core-shell nanosystem. The reflectivity of the obtained core-shell structure measured by UV/vis spectrometry showed a comparatively low reflectivity in the visible-light region, which implied good optical absorption performance. The water splitting performance of the obtained Si NWs, planar Si/Cu2O structure and Si NW/Cu2O core-shell nanosystem were studied. Owing to the large specific surface area, heterojunctions formed between Cu2O nanocrystallites and Si NWs and the light trapping effect of the NW array structure, the photocatalytic performance of the Si NW/Cu2O core-shell nanosystem increased markedly compared with that of pure silicon NWs and a planar Si/Cu2O structure, which means excellent hydrogen production capacity under irradiation with simulated sunlight. In addition, the photocatalytic performance of the core-shell nanosystem was improved obviously after platinum nanoparticles were electrodeposited on it.

The oligomerization of cyclopentadiene (CPD) and its dimer, dicyclopentadiene (DCPD), to tricyclopentadiene (TCPD) through Diels-Alder reaction at temperatures between 120 and 150°C was investigated. The results show that reaction temperature, pressure and solvent influence the product yield; at 150°C up to 50% yield of TCPD was obtained in the absence of solvents. The ratios of isomers A to B in the product can be adjusted by using different solvents. The kinetics indicate that the rate is more sensitive to the concentration of CPD than to that of DCPD.

The kinetics of tricyclopentadiene hydrogenation to tetrahydrotricyclopentadiene over Pd-B/γ-Al2O3 amorphous catalyst has been studied in a stirred semibatch reactor over a range of temperatures (353−413 K), hydrogen pressures (1.0−3.5 MPa), initial feed concentrations (0.2−0.4 mol/L), and catalyst concentrations (0.60−5.33 g/L). The reaction is found to be a consecutive reaction with 14,15-dihydrotricyclopentadiene as the intermediate product. Analysis verifies that the kinetic experiments are conducted in the absence of mass transfer resistance. An Eley−Rideal kinetic model is formulated with the assumption that single-site adsorbed organic species are saturated by hydrogen dissolved in the liquid phase and the surface reaction is rate-determining. This model can accurately fit the experimental data in the ranges studied and correctly explain the observed tendencies. The kinetic parameters are obtained by minimizing the error between the model predications and the experimental results. The activation energies for the first and second step reactions are 11.11 kJ/mol and 34.71 kJ/mol, respectively. The kinetic model provides a useful tool for the reactor design and performance estimation of amorphous Pd catalysts.