A Review on the Role of Amorphous Aluminum Compounds in Catalysis: Avenues of Investigation and Potential Application in Petrochemistry and Oil Refining

Abstract

Aluminum oxides and hydroxides are widely applied because of the great variety of their modifications. In particular, aluminum oxides and hydroxides are used in petrochemistry and oil refining. However, amorphous aluminum compounds have not been sufficiently studied due to the complexity of their synthesis and the problems encountered during their study. The study of amorphous aluminum compounds is hindered by the ambiguity of terminology. In this work, the structures of amorphous aluminum compounds prepared by different methods and the properties that determine their applications have been highlighted in detail. Amorphous aluminum compounds play both positive and negative roles in petrochemistry; however, in petroleum refining, amorphous compounds (without promoters and transition metal salts) demonstrate a promising catalytic performance in oil upgrading.

Analysis of the geotechnological potential of heavy oil/bitumen production based on the improved method of well hydraulic production

“…The nanosized catalyst is introduced into the well together with superheated steam, i.e. practically without additional investment in equipment [26].…”

Nitrate adsorption characteristics of synthesized allophanes with various chemical compositions

“…In general, the formation of pseudo-boehmite is carried out by dehydration of amorphous aluminum hydroxide through a condensation and polymerization process in which water is released from a highly hydrated gel. The formation of crystalline aluminum hydroxides by the mechanism of dissolution and precipitation from amorphous compounds under hydrothermal conditions suggests lower energy consumption during crystallization due to the absence of long-range order in the arrangement of atoms of the amorphous phase (Mukhamed'yarova et al, 2021). It is assumed that the pseudo-boehmite, in whose crystal structure Al-OH2 + is present, may have been deposited on the surface of the synthesized allophane domains (primary floccules), and contributed to the increase of nitrate adsorption performance (Kloprogge et al, 2006).…”

Diversity of transformation of heteroallenes on acenaphthene-1,2-diimine aluminum oxide

“…The high interest in these objects is due to the fact that these compounds are effective catalysts and co-catalysts in the polymerization of a wide range of organic molecules. 1–3 However, even the simplest co-catalyst in alkene polymerization, methylalumoxane (MAO), has not yet been structurally characterized, and its mechanism of action has not been fully understood. 4–6 It is known that MAOs containing simple Me–Al–O monomer units form various types of clusters, while the use of N,N-chelating ligands allows forming monomeric MAO derivatives.…”