Authors:

Nicholas Barmore

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About Paper:

For over 70 years chemical engineers have been researching and developing light olefin oligomerization, primarily for use as higher molecular weight fuels. Zeolites are one such catalyst that can be used for this process. They are silicon aluminum crystals with Bronsted acid sites on each aluminum ion. Although it can form 6 bonds, Al forms only 4 in zeolites, all to oxygen, which are subsequently bonded to silicon. This undercoordination allows these Al sites to act as Bronsted acids through a charge imbalance between it and the silicon ion. Silica alumina is another catalyst but is comprised of silicon aluminum oxides. For comparison, silica alumina has ~10,000 times less catalytic activity. While Al-O-Al, or aluminum oxide, bonds are non- reactive, we hypothesize that there are a few Al-O(H)-Si bonds, the same as those in zeolites, that act as Bronsted acids within silica alumina, which explains its slight activity. The scope of this project aims to synthesize these sites on the surface of non-reactive silica. These will then be compared to commercially available zeolites for things like conversion, selectivity, rates, and stability. Preliminary results show that a highly reactive catalyst can be prepared, as well as evidence for Bronsted acid sites such as cracking and skeletal isomerization as products of the oligomerization reaction. Determination of the number and characterization of the type of active sites will be determined to quantify the differences in these catalysts with those of zeolites. Keywords: Aluminosilicate; Catalyst; Oligomerization; Zeolites

Source:

Purdue University / 2024

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No topics listed

Co-authors:

Nicholas Barmore