Abstract
The mediated electrosynthesis of H2O2 in acidic solutions (pH 0.9–3.0) was investigated in a three-phase, aqueous/organic/gaseous system using 2-ethyl-9,10-anthraquinone (EtAQ) as mediator (redox catalyst). The main hydrogen peroxide producing route is the in situ mediating cycle: EtAQ electroreduction–homogeneous oxidation of anthrahydroquinone (EtAQH2). The organic phase was composed of tributylphosphate solvent (TBP) with 0.2 M tetrabutylammonium perchlorate (TBAP) supporting electrolyte, 0.06 M tricaprylmethylammonium chloride (A336) surface active agent, and 0.1–0.2 M EtAQ mediator. Part I of this two part work deals with the physico-chemical characteristics of the emulsion electrolyte (e.g., ionic conductivity, emulsion type, H2O2 partition between the aqueous and organic phases), and kinetic aspects (both electrode and homogenous) of the mediation cycle. Furthermore, batch electrosynthesis experiments are presented employing reticulated vitreous carbon cathodes (specific surface area 1800 m2 m−3) operated at superficial current densities of 500–800 A m−2. During 10 h batch electrolysis involving the emulsion mediated system with O2 purge at 0.1 MPa pressure, H2O2 concentrations in the range 0.53–0.61 M were obtained in 0.1 M H2SO4 (pH 0.9) and 2 M Na2SO4(acidified to pH3). The corresponding apparent current efficiencies were from 46 to 68%. Part II of the present work describes investigations using flow-by fixed-bed electrochemical cells with co-current upward three-phase flow.
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References
C.W. Oloman, ‘Electrochemical Processing for the Pulp and Paper Industry’, The Electrochemical Consultancy, Romsey, UK (1996).
J.R. Anderson and B. Amini, in C.W. Dence and D.W. Reeve, (Eds), ‘Pulp Bleaching: Principles and Practice’ (TAPPI Press, Atlanta, 1996), pp. 117–133.
E.L. Gyenge and C.W. Oloman, J. Appl. Electrochem. 31 (2001) 233.
Z. Qiang, J-H. Chang and C-P. Huang, Water Res. 36 (2002) 85.
O. El Mouahid, C. Coutanceau, E.M. Belgsir, P. Crouigneau, J.M. Leger and C. Lamy, J. Electroanal. Chem. 426 (1997) 117.
C. Degrand, J. Electroanal. Chem. 169 (1984) 259.
M.S. Wrighton, Science 231 (1986) 32.
B. Keita and L. Nadjo, J. Electronal. Chem. 145 (1983) 431.
P. Tissot and A. Huissoud, Electrochim. Acta 41 (1996) 2451.
A. Huissoud and P. Tissot, J. Appl. Electrochem. 28 (1998) 653.
E.L. Gyenge, ‘Phase-transfer mediated electroreduction of oxygen to hydrogen peroxide in acid and alkaline electrolytes’, PhD dissertation, The University of British Columbia, Vancouver, Canada (2001).
A. Paren and T. Tsujino, Japan Tappi J. 52 (1998) 630.
R.F. Knarr, M. Velasco, S. Lynn and C.W. Tobias, J. Electrochem. Soc. 139 (1992) 948.
A. Huissoud and P. Tissot, J. Appl. Electrochem. 29 (1999) 11.
A. Huissoud and P. Tissot, J. Appl. Electrochem. 29 (1999) 17.
M. Nozaki, Japan Tappi J. 52 (1998) 616.
I. Mathur and R. Dawe, Tappi J. 82 (1999) 157.
R. Dworak, H. Feess and H. Wendt, AIChE Symp. Ser. No. 185 75 (1979) 38.
H. Feess and H. Wendt, J. Chem. Tech. Biotechnol. 30 (1980) 297.
H. Feess and H. Wendt, Ber. Buns. Ges. Phys. Chem. 85 (1981) 914.
J.A. Dean (Ed.), ‘Lange's Handbook of Chemistry’ (McGraw-Hill, New York, 1992).
S.H. Maron and C.F. Prutton, ‘Principles of Physical Chemistry’ (Macmillan, London, 4th edn, 1971).
http://www.chevronphillips.matweb.com/brochures/mxdiethybenbro. pdf.
http://www.inchem.org/documents/ehc/ehc/ehc112.htm.
S. Budavari (Ed.), ‘Merck Index’ (Merck & Co., Rahway, NJ, 11th edn, 1989).
L. Sigrist, O. Dossenbach and N. Ibl, J. Appl. Electrochem. 10 (1980) 223.
P. Becher, ‘Emulsions: Theory and Practice’ (Reinhold, New York, 1957).
J.F. Rusling, in B.E. Conway, J.O'M. Bockris and R.E. White (Eds), ‘Modern Aspects of Electrochemistry’, No. 26 (Plenum, New York, 1994).
A. Babaei, P.A. Connor and J.A. McQuillan, J. Chem. Ed. 74 (1997) 1200.
K. Pekmez, M. Can and A. Yildiz, Electrochim. Acta 38 (1993) 607.
V.J. Jennings, T.E. Forster and J. Williams, Analyst 95 (1970) 718.
C. Russel and W. Jaenicke, J. Electroanal. Chem. 180 (1984) 205.
J. Posdorfer, M. Olbrich-Stock and R.N. Schindler, Z. Phys. Chem. 171 (1991) 33.
‘Reticulated Vitreous Carbon’, Technical literature, ERG Materials and Aerospace Co., Oakland (1996).
E.R. Brown and J.R. Sandifer, in B.W. Rossiter and J.F. Hamilton (Eds), ‘Physical Methods of Chemistry’, Vol. II, ‘Electrochemical Methods’ (J. Wiley & Sons, New York, 2nd edn, 1986). pp. 273–432.
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Gyenge, E., Oloman, C. Electrosynthesis of hydrogen peroxide in acidic solutions by mediated oxygen reduction in a three-phase (aqueous/organic/gaseous) system Part I: Emulsion structure, electrode kinetics and batch electrolysis. Journal of Applied Electrochemistry 33, 655–663 (2003). https://doi.org/10.1023/A:1025082709953
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DOI: https://doi.org/10.1023/A:1025082709953