Ammonolysis of ethanol on pure and zinc oxide modified HZSM-5 zeolites

Design of amphoteric mixed oxides of zinc and Group 3 elements (Al, Ga, In): migration effects on basic features

“…The pure (ZnO, Ga 2 O 3 , Al 2 O 3 , In 2 O 3 ) and mixed oxides (Ga-Zn, Al-Zn, In-Zn) were prepared following a process adapted from a work by Naik and Fernandes, 2,14 by heating intimate mixtures of metal nitrates, oxalic acid and urea in air (50 mL min À1 ) at 653 K for 7 h. During the synthesis process, the mixing of both nitrates resulted in desorption of water from the salts leading to a cream-like precursor. Table 1 gathers molar ratios of the precursors of prepared oxides and the effective metal amounts (relative molar ratios X : 100 À X) as measured by chemical analysis (ICP-OES ''Activa'' Jobin Yvon).…”

“…13 The lower temperature syntheses and the mixing or supporting of zinc oxide on other oxides can improve its specific surface area, which is advantageous for a heterogeneous catalyst. In this article, in order to design new series of amphoteric catalysts, mixed oxides were synthesized via a process adapted from Naik and Fernandes, 2,14 while the evolution of their acid-base features was monitored by adsorption microcalorimetry. Deriving the total number of acidic and basic sites and their corresponding strengths, and associating it with characterization by XRD and XPS analyses brought more understanding on the nature of these new amphoteric oxides.…”