Reduced phosphorus compounds (phosphorus with oxidation number less than +5) are and often ignored component of the global phosphorus cycle. This paper highlights environments in which reduced phosphorus compounds may be significant, reviews their importance in industrial applications and products, and examines their possible production by anaerobic bacteria or the steel industry. The role of reduced phosphorus in corrosion of iron and steel is worthy of additional research, since reduced phosphorus compounds can catalyze iron corrosion, and corrosion can liberate significant quantities of reduced phosphorus to the environment. The recent discovery that volcanic emissions can contain phosphorus is also deserving of additional study, given its potential impact on the global phosphorus cycle and the likelihood that reduced phosphorus compounds may be present.
This work was supported by the National Science Foundation (NSF) under grant BES-0201849. The opinions, findings, conclusions, and recommendations are those of the authors and do not necessarily reflect the views of the NSF.
Notes
a Values for ϵ° correspond to unit activities of indicated reactions in water at pH 7.0 and 25°C.
b pH2: 0.05 atm.