Editing Hydrogen (section)

====Serpentinization====
[[Serpentinization]] is a geological mechanism that produce highly [[Reduction (chemistry)|reducing]] conditions.<ref name=FrostBeard2007>{{cite journal |last1=Frost |first1=B. R. |last2=Beard |first2=J. S. |title=On Silica Activity and Serpentinization |journal=Journal of Petrology |date=3 April 2007 |volume=48 |issue=7 |pages=1351–1368 |doi=10.1093/petrology/egm021|url=http://petrology.oxfordjournals.org/content/48/7/1351.full.pdf }}</ref> Under these conditions, water is capable of oxidizing ferrous ({{chem|Fe|2+}}) ions in [[fayalite]], generating hydrogen gas:<ref name="Dincer-2015">{{Cite journal |last1=Dincer |first1=Ibrahim |last2=Acar |first2=Canan |date=14 September 2015 |title=Review and evaluation of hydrogen production methods for better sustainability |url=https://www.sciencedirect.com/science/article/pii/S0360319914034119 |url-status=live |journal=International Journal of Hydrogen Energy |language=en |volume=40 |issue=34 |pages=11094–11111 |bibcode=2015IJHE...4011094D |doi=10.1016/j.ijhydene.2014.12.035 |issn=0360-3199 |archive-url=https://web.archive.org/web/20220215183915/https://www.sciencedirect.com/science/article/abs/pii/S0360319914034119 |archive-date=15 February 2022 |access-date=4 February 2022}}</ref><ref>{{Cite journal| last = Sleep| first = N.H.| author2 = A. Meibom, Th. Fridriksson, R.G. Coleman, D.K. Bird| year = 2004| title = H<sub>2</sub>-rich fluids from serpentinization: Geochemical and biotic implications| journal = Proceedings of the National Academy of Sciences of the United States of America| volume = 101| issue = 35| pages = 12818–12823| doi = 10.1073/pnas.0405289101|bibcode = 2004PNAS..10112818S| pmid=15326313| pmc=516479| doi-access = free}}</ref>
:{{chem2|Fe2SiO4 + H2O → 2 Fe3O4 + SiO2 + H2}}

Closely related to this geological process is the [[Schikorr reaction]]:
:{{chem2|3 Fe(OH)2 → Fe3O4 + 2 H2O + H2}}
This process also is relevant to the corrosion of [[iron]] and [[steel]] in [[Anoxic waters|oxygen-free]] [[groundwater]] and in reducing [[soil]]s below the [[water table]].<ref>{{cite journal |author1=Stephan Kaufhold |author2=Stephen Klimke |author3=Stefan Schloemer |author4=Theodor Alpermann |author5=Franz Renz |author6=Reiner Dohrmann |title=About the Corrosion Mechanism of Metal Iron in Contact with Bentonite |journal=ACS Earth and Space Chemistry |date=2020 |volume=4 |issue=5 |pages=711–721 |doi=10.1021/acsearthspacechem.0c00005 |bibcode=2020ESC.....4..711K |language=en}}</ref>