Authors:G. Boskovic, A. Zarubica, M. Kovacevic, and P. Putanov
Properties of two catalysts tailored in the laboratory conditions by sulfation of commercial Zr-hydroxide and Zr-hydroxide
of nitrate origin were compared with those of commercial SO4-Zr-hydroxide. Equally thermally treated samples in the temperature interval 500–700°C, and having the same amount of sulfur,
show different properties indicating memory effect of their solid parent materials. The catalyst obtained by sulfation of
commercial Zr-hydroxide differs in amount of residual sulfates upon calcination from other two catalysts. The instability
of sulfates in the previous case might be connected to the lowest surface area values of catalyst and the highest fraction
of monoclinic phase observed at all applied calcination temperatures.
Authors:E. Kiš, G. Lomić, G. Bošković, R. Marinković-Nedučin, and P. Putanov
The re-oxidation of low-pressure methanol synthesis catalyst was followed by means of DSC, with the aim of contributing to
a better understanding of the processes taking place during catalyst blanketing, stabilization and re-oxidation. The investigations
were carried out with previously hydrogen-reduced samples, and their successive re-oxidation was performed with different
oxygen contents in the oxygen/nitrogen gas mixtures. A procedure for catalyst stabilization and/or catalyst discharge is proposed.