Characterization of the acidic and basic properties of αLiAIO₂, γLiAIO₂, and calcined "HAIO₂" using isopropyl alcohol

Characterization of both the acidic and basic sites of αLiAIO₂, γLiAIO₂, and calcined "HAIO₂" was carried out with the isopropyl alcohol probe reaction. All three materials catalyzed the formation of both propylene and acetone. The formation of propylene is indicative of acidic-basic pair sites, while the presence of acetone is indicative of basic sites. In addition to the formation of both propylene and acetone, base-catalyzed acetone aldol condensation products were formed on both αLiAIO₂ and calcined "HAIO₂." Both materials produced a C6DIENE (2-methyl-1,3-pentadiene or 4-methyl-1,3-pentadiene) aldol condensation product, while αLiAIO₂ also produced the aldol condensation products 4M2PONE (4-methyl-2-pentanone) and 4M2POL (4-methyl-2-pentanol). The reaction pathways that describe the formation of the various C6 products were used to infer the nature of the basic sites on the materials. Additional information obtained from TPD and FTIR of chemisorbed CO₂ demonstrate that the basic sites on αLiAIO₂ are similar in strength and number to MgO.