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The use of AlPO4−ZrO2 (weight ratio AlPO4/ZrO2=3) as catalyst systems obtained with ethylene oxide and subjected to different stages of heat treatments has been studied through their catalytic activity in the skeletal isomerization of cyclohexene to 1- and 3-methylcyclopentenes (1- and 3MCP). The apparent rate constants and selectivity to 1-MCP are used for an evaluation of the presence and amount of strong acid sites, the only ones capable of giving rise to skeletal isomerization. The decrease in catalytic activity as calcination increases is consistent with not only the decrease in the amount of acid sites measured vs. weaker organic bases but also with the decrease in Brönsted acidity, as shown by the decrease in O−H band intensity.

The surface acidity and basicity of AlPO4-ZrO2 (weight ratio AlPO4/ZrO2=3) systems obtained with ethylene oxide and subjected to different stages of heat treatment has been studied through the irreversible adsorption of organic bases and benzoic acid. The decrease in the amount of acid sites as calcination increases is consistent with the decrease in Brönsted acidity, as shown by the decrease in O−H band intensity. Infrared spectra show Td symmetry in which the phosphorus atom is surrounded by the tetrahedra of oxygen atoms.

The effects of surface dehydration on textural properties, crystallinity and the structure of AlPO4−ZrO2 (weight ratio AlPO4/ZrO2=3) systems precipitated with ethylene oxide have been studied by N2 adsorption and XRD measurements. The increase in calcination temperature in the range 773–1273 K decreases the textural parameters as a consequence of AlPO4 crystallization to the tridymite form.

The lattice-dynamical properties of the intermediate oxide of tin (IO) have been investigated over the temperature range 80–295 K. The logarithm of the recoil-free fraction varied linearly with temperature. However, a Debye model does not give a good account of this dependence. By comparison with the other oxides of the Sn-O system, the recoil-free fraction for tin atoms with 2+ and 4+ oxidation states of the IO were estimated. At room temperature, they are 0.463 and 0.323 for 4+ and 2+ states respectively.

We have investigated experimentally and by computer simulations the energy-loss distributions of low-energy (E<10 keV) protons and deuterons transmitted through polycrystalline palladium thin films. In contrast to previous experiments on various transition metals we find that the stopping power of Pd is proportional to the ion velocity. Data of protons and deuterons are coincident within the experimental uncertainties, showing the absence of an isotopic effect on the stopping power of Pd in this energy range. The experimental results were analyzed and compared with Monte Carlo computer simulations and previous theoretical models. The difference in the velocity dependence of the energy loss of hydrogen ions in Pd with respect to other transition metals (Cu, Ag, and Au) is explained by a theoretical analysis based on the properties of the d-electron bands of those elements. [ABSTRACT FROM AUTHOR]