|Molar mass||2878.2 g/mol|
|EU Index||Not listed|
|Related heteropoly acids||Phosphotungstic acid|
|Related compounds||Tungsten trioxide
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
|(what is: / ?)|
Silicotungstic acid (also known as tungstosilicic acid) is the most commonly encountered heteropoly acid. It is a pale yellow solid with the chemical formula H4[W12SiO40]. It is used as a catalyst in the chemical industry.
- C2H4 + CH3CO2H → CH3CO2C2H5
It has also been commercialized for the oxidation of ethylene to acetic acid:
- C2H4 + O2 → CH3CO2H
It has also recently been proposed as a mediator in production of hydrogen through electrolysis of water by a process that would reduce the danger of explosion while allowing efficient hydrogen production at low current densities, conducive to hydrogen production using renewable energy. 
Synthesis and structure
The free acid is produced by combining sodium silicate and tungsten trioxide followed treatment of the mixture with hydrochloric acid. The polyoxo cluster adopts a Keggin structure, with Td point group symmetry.
- Misono, Makoto "Recent progress in the practical applications of heteropolyacid and perovskite catalysts: Catalytic technology for the sustainable society" Catalysis Today 2009, vol. 144, pp. 285-291. http://dx.doi.org/10.1016/j.cattod.2008.10.054
- Rausch, Benjamin; Symes, Mark D.; Chisholm, Greig; Cronin, Leroy (September 12, 2014). "Decoupled catalytic hydrogen evolution from a molecular metal oxide redox mediator in water splitting". Science (American Association for the Advancement of Science) 345 (6202): 1326–1330. doi:10.1126/science.1257443. Retrieved October 6, 2014.
- Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY.
|This inorganic compound–related article is a stub. You can help Wikipedia by expanding it.|