For more than two centuries after Volta (1745 – 1827) (http://www.ecsblog.org/the-birthplace-of-electrochemistry), aqueous redox potentials have been conventionally referred to that of the standard hydrogen electrode (SHE) as zero, in the absence of a proper knowledge of the latter. The author demonstrated for the first time (Heyrovska, 2009) a new simple linear relation between the gaseous ionization potentials (I) and the aqueous standard redox potentials (E⁰) using the existing data for the elements of various Groups in the Periodic Table. It was astonishing that all these straight lines converged to one point at I = 0, yielding the absolute potential of SHE, E⁰_I=0 = 4.20 (+/- 0.03)V.

    This value was found to be close to the theoretical value (4.44V) obtained earlier by Trasatti (1986) (Pure & Appl. Chem. 58 (1986) 955) and to the experimental value, 4.2 (+/-0.4V) obtained by Donald et al, (2008) (J. Am. Chem. Soc. 130 (2008) 3371). Thus, by knowing the absolute value of SHE, the absolute aqueous redox potentials, E^o_abs = E^o - E^o_{I =0}, of all the elements of the Periodic Table (Heyrovska, 2010) as well as of the standard reference electrodes were obtained and tabulated (Heyrovska, 2009, 2010, 2011). Full list of references in: http://www.jh-inst.cas.cz/~rheyrovs/publs.htm. Some selected references are given below.

 

References

1. Absolute Potentials of the Hydrogen Electrode and of Aqueous Redox Couples
R. Heyrovska, Electrochemical and Solid-State Letters, 12(10) (2009) F29-F30.

2. Absolute aqueous redox potentials (via a new link between aqueous and gaseous properties)

R. Heyrovska, 1) 9th workshop of physical chemists and electrochemists, Brno, June 2009; http://www.chemi.muni.cz/~libuse/setkani2009/index.html
2) http://precedings.nature.com/documents/3395/version/1 (2009).

3. Aqueous Redox Potentials Found to be Inversely Proportional to the Bohr Radius

R. Heyrovska, 1) 216th ECS Meeting, Vienna, Austria, October 2009: Electrochem. Soc. 902, 3067, 2009. (Abstract); 2) http://ecsmeet6.peerx-press.org/ms_files/ecsmeet6/2009/04/24/00004143/00/4143_0_art_0_k6mfy4_cnvpdf.pdf ; 3) Electrochem. Soc. Trans., 25, (2010) 159-163. 

4. Absolute potentials of standard reference electrodes at 25 ⁰C

R. Heyrovska, 1) MEM 2009 conference, dedicated to Prof. J. Heyrovsky on the occasion of the 50th Anniversary of the award of the Nobel Prize for Polarography, Prague, 9-13 December 2009: http://www.natur.cuni.cz/heyrovsky; 2) Conference Proceedings: Chemicke Listy, 103 (2009) OP-10, s238: http://www.chemicke-listy.cz ;

3) Proceedings of the Modern Electroanalytical Methods 2009, 13-Prague, Czech Republic, 9- December 2009, Department of Chemistry, Faculty of Science, Charles University, Editors: J. Barek, K. Nesmìrák,OP-10, page 10 in: http://web.natur.cuni.cz/heyrovsky/Heyrovsky2009 Proceedings complete.pdf ;
4) http://precedings.nature.com/documents/4354/version/1 (2010)

5. Radii of redox components from absolute redox potentials compared with covalent and aqueous ionic radii
R. Heyrovska, Electroanalysis, 22 (Issue 9), (2010) 903 - 907, Published online; 4 March 2010.