Effect of acidity of oxide support on the activity and stability of μ-nitrido diiron phthalocyanine complex

Abstract

Various oxides, including Al 2 O 3 , Fe 2 O 3 , SiO 2 , and ZrO 2 , were employed as catalyst supports for the oxidation of cyclohexane by a μ-nitrido-bis[tetra(tert-butyl)phthalocyaninatoiron] complex. These oxide supports were characterized by Brunauer–Emmett–Teller surface area measurements and NH 3 temperature-programmed desorption analyses. The catalyst supported on Al 2 O 3 , which has the highest acidity among the oxides considered here, showed the best activity with a turnover number (TON) of ˜108.8, without any co-catalyst. Furthermore, recycle tests of the catalysts revealed a TON of 69.3 for the Al 2 O 3 -supported catalyst after the third run. The strongly acidic sites in the Al 2 O 3 support could be responsible for the strong adsorption of μ-nitrido diiron phthalocyanine, resulting in enhanced catalytic activity and stability. © 2019 Institution of Chemical Engineers