Editing Formaldehyde (section)

==Synthesis and industrial production==
===Laboratory synthesis===
Formaldehyde was discovered in 1859 by the Russian chemist [[Aleksandr Butlerov]] (1828–1886) when he attempted to synthesize methanediol ("methylene glycol") from [[iodomethane]] and [[silver oxalate]].<ref>{{Cite wikidata|Q55881565}}</ref> In his paper, Butlerov referred to formaldehyde as "dioxymethylen" (methylene dioxide) because his empirical formula for it was incorrect, as atomic weights were not precisely determined until the [[Karlsruhe Congress]].

The compound was identified as an aldehyde by [[August Wilhelm von Hofmann]], who first announced its production by passing methanol vapor in air over hot platinum wire.<ref>See: A. W. Hofmann (14 October 1867) [https://books.google.com/books?id=Vh4XAAAAYAAJ&pg=PA665 "Zur Kenntnis des Methylaldehyds"] ([Contributions] to our knowledge of methylaldehyde), ''Monatsbericht der Königlich Preussischen Akademie der Wissenschaften zu Berlin'' (Monthly Report of the Royal Prussian Academy of Sciences in Berlin), vol. 8, pages 665–669. Reprinted in:
*A.W. Hofmann, (1868) [https://books.google.com/books?id=RgEuAAAAIAAJ&pg=PA357 "Zur Kenntnis des Methylaldehyds"], ''Annalen der Chemie und Pharmacie'' (Annals of Chemistry and Pharmacy), vol. 145, no. 3, pages 357–361.
*A.W. Hofmann (1868) [https://books.google.com/books?id=4hNLAAAAYAAJ&pg=PA246 "Zur Kenntnis des Methylaldehyds"], ''Journal für praktische Chemie'' (Journal for Practical Chemistry), vol. 103, no. 1, pages 246–250.
However, it was not until 1869 that Hofmann determined the correct empirical formula of formaldehyde. See: A.W. Hofmann (5 April 1869) [https://books.google.com/books?id=58YAAAAAYAAJ&pg=PA362 "Beiträge zur Kenntnis des Methylaldehyds"], ''Monatsbericht der Königlich Preussischen Akademie der Wissenschaften zu Berlin'', vol. ?, pages 362–372. Reprinted in:
*{{cite journal | last1 = Hofmann | first1 = A.W. | year = 1869 | title = Beiträge zur Kenntnis des Methylaldehyds | url = https://books.google.com/books?id=2AIwAAAAIAAJ&pg=PA414 | journal = Journal für Praktische Chemie | volume = 107 | issue = 1| pages = 414–424 | doi=10.1002/prac.18691070161}}
*A.W. Hofmann (1869) "Beiträge zur Kenntnis des Methylaldehyds," ''Berichte der Deutschen Chemischen Gesellschaft'' (Reports of the German Chemical Society), vol. 2, pages 152–159.</ref><ref>{{cite book|first=J.|last=Read|title=Text-Book of Organic Chemistry|publisher=G Bell & Sons|location=London|year=1935}}</ref> With modifications, Hofmann's method remains the basis of the present day industrial route.

Solution routes to formaldehyde also entail oxidation of methanol or [[iodomethane]].<ref>{{cite journal|doi=10.1002/anie.200800991|title=A Simple, Rapid Method for the Preparation of &#91;11C&#93;Formaldehyde|year=2008|last1=Hooker|first1=Jacob M.|last2=Schönberger|first2=Matthias|last3=Schieferstein|first3=Hanno|last4=Fowler|first4=Joanna S.|journal=Angewandte Chemie International Edition|volume=47|issue=32|pages=5989–5992|pmid=18604787|pmc=2522306}}</ref>

===Industry===
Formaldehyde is produced industrially by the catalytic oxidation of [[methanol]]. The most common catalysts are [[silver]] metal (i.e. the [[Fasil process|FASIL process]]), [[iron(III) oxide]],<ref>{{Cite journal |last1=Wang |first1=Chien-Tsung |last2=Ro |first2=Shih-Hung |date=2005-05-10 |title=Nanocluster iron oxide-silica aerogel catalysts for methanol partial oxidation |url=https://www.sciencedirect.com/science/article/pii/S0926860X05001523 |journal=Applied Catalysis A: General |language=en |volume=285 |issue=1 |pages=196–204 |doi=10.1016/j.apcata.2005.02.029 |bibcode=2005AppCA.285..196W |issn=0926-860X}}</ref> iron molybdenum [[oxide]]s (e.g. iron(III) [[molybdate]]) with a [[molybdenum]]-enriched surface,<ref>{{Cite journal |last1=Dias |first1=Ana Paula Soares |last2=Montemor |first2=Fátima |author-link2=Maria de Fátima Montemor|last3=Portela |first3=Manuel Farinha |last4=Kiennemann |first4=Alain |date=2015-02-01 |title=The role of the suprastoichiometric molybdenum during methanol to formaldehyde oxidation over Mo–Fe mixed oxides |url=https://www.sciencedirect.com/science/article/pii/S1381116914004774 |journal=Journal of Molecular Catalysis A: Chemical |language=en |volume=397 |pages=93–98 |doi=10.1016/j.molcata.2014.10.022 |issn=1381-1169}}</ref> or [[vanadium pentoxide|vanadium]] [[oxide]]s. In the commonly used [[formox process]], methanol and oxygen react at c.&nbsp;250–400&nbsp;°C in presence of iron oxide in combination with molybdenum and/or vanadium to produce formaldehyde according to the [[chemical equation]]:<ref name="Ullmann">{{Ullmann|doi=10.1002/14356007.a11_619|title=Formaldehyde|year=2000|last1=Reuss|first1=Günther|last2=Disteldorf|first2=Walter|last3=Gamer|first3=Armin Otto|last4=Hilt|first4=Albrecht|isbn=3527306730}}</ref>
:2{{nbsp}}CH<sub>3</sub>OH + O<sub>2</sub> → 2{{nbsp}}CH<sub>2</sub>O + 2{{nbsp}}H<sub>2</sub>O

The silver-based catalyst usually operates at a higher temperature, about 650&nbsp;°C. Two chemical reactions on it simultaneously produce formaldehyde: that shown above and the [[dehydrogenation]] reaction:
:CH<sub>3</sub>OH → CH<sub>2</sub>O + H<sub>2</sub>

In principle, formaldehyde could be generated by oxidation of [[methane]], but this route is not industrially viable because the methanol is more easily oxidized than methane.<ref name="Ullmann"/>