Pure vs ultra-pure γ-alumina: A spectroscopic study and catalysis of ethanol conversion

Acido-basicity of lanthana/alumina catalysts and their activity in ethanol conversion

“…The samples considered in this paper were prepared by incipient wetness impregnation technique using a well-known alumina support which was the object of previous characterization studies 16,18 .…”

“…Previous studies have shown that the performance of alumina, although very good, is limited by the production of small amounts of higher hydrocarbons [16][17][18][19] . A main point, additionally, is catalyst stability, due to the growth of carbonaceous materials that may progressively poison the catalyst 19 .…”

Formation of Phases and Porous System in the Product of Hydrothermal Treatment of χ-Al2O3

“…Active alumina (γ-Al 2 O 3 ) is widely used in the chemical industry as catalysts for petrochemical and refinery processes, catalyst supports and adsorbents [1][2][3][4][5]. χ-Al 2 O 3 is one of the most acidic modifications of alumina.…”

On the use of infrared spectrometer as detector for Temperature Programmed (TP) techniques in catalysts characterization

“…Among the advantages of this 22 technique, ammonia is a small molecule and thus it can access in 23 the narrowest pores of zeolite structure, having then available and 24 accessible the entire surface and the several different types of acid 25 sites that may adsorb this probe molecule, avoiding confinement 26 effects present when using other probes. In addition, ammonia is a 27 medium-strong base and this allows the building of a trustful scale 28 of acid strength based on its chemisorption energy [9]. Major 29 drawbacks of this technique have been well described in the 30 literature [3,10]: in fact, NH 3 can be adsorbed on the non-acidic 31 part of the surface, the peak temperature might be not related 32 directly to the acid strength for its relation with experimental 33 conditions applied and redox reactions might happen producing 34 N 2 or NO x .…”