Formation of hydrogen peroxide from coal tar as hydrogen sources using 9-mesityl-10-methylacridinium ion as an effective photocatalyst

Visible light irradiation of an O2-saturated acetonitrile (MeCN) solution containing 9-mesityl-10-methylacridinium ion (Acr+–Mes) and MeCN-extracted coal tar results in formation of hydrogen peroxide (H2O2). Anthracene and other aromatic hydrocarbons contained in coal tar act as hydrogen sources in the photocatalytic reduction of O2 to produce H2O2. The photocatalytic formation of H2O2 is initiated by photoexcitation of Acr+–Mes, which results in formation of the electron-transfer state: Acr–Mes+, followed by electron-transfer from coal tar to the Mes+ moiety and electron-transfer from the Acr moiety to O2.