Redox activity of nickel and vanadium porphyrins: a possible mechanism behind petroleum genesis and maturation?

The presence of metalloporphyrins in crude oil has been known for many years. In contrast, their role on the physical–chemical properties is only now beginning to be understood. In this study, we test using high-level ab initio calculations, the hypothesis of a possible redox catalytic activity of vanadium and nickel metalloporphyrins in crude oil, illustrated by the oxidation of methanol to formaldehyde and hydrogen dissociation, respectively. This process which may take place during petroleum genesis and maturation, explains some of its physical–chemical properties, such as polar chains, the absence of alcohols, the trapping of porphyrins within macromolecular aggregates.