The SrO–Nb2O5 system, especially Sr5Nb4O15 compound is of interest for their use as an electroceramics. In this work, was synthesized by solid-state reaction and characterised XRD. Thermodynamic properties like heat capacity, enthalpy formation Gibbs energy have been measured. standard molar Sr5Nb4O15(s) determined using oxide melt solution high temperature calorimeter. Based on these experimen...

RESUMO A produção de álcoois pela hidrogenação do CO na presença um catalisador, normalmente Cu/ZnO/Al2O3, em pressões 50-100 bar e temperaturas faixa 220 a 300 °C, é uma importante rota metanol. Neste cenário, novo catalisador foi sintetizado substituindo o ZnO por Nb2O5, que sua vez, trata-se matéria prima nacional com propriedades semicondutoras semelhantes ao óxido zinco, sendo pouco invest...

Amorphous catalytic materials belonging to the Nb 2 O 5 –P –SiO system were prepared through an original sustainable sol-gel procedure, and characterized by surface area, porosity acidity measurements. Their acid properties have been investigated FT-IR spectroscopy of adsorbed pyridine, ammonia titration TPR, as well with 2-phenylethylamine from organic solution. They present Lewis attributed n...