Zeolite Modified Electrodes

D. Rolison, Zeolite-modified electrodes and electrode-modified zeolites. Chem. Rev. 90, 867—878 (1990). 

Refs. [i] Rolison DR (1994) The intersection of electrochemistry with zeolite science. In Jansen JC, Stacker M, Karge HG, Weitkamp / (eds) Advanced zeolite science and applications. Elsevier, Amsterdam [ii] Walcarius A (2003) Implication of zeolite chemistry in electrochemical science and applications of zeolite-modified electrodes. In Auerbach SM (ed) CRC handbook of zeolite science and technology. CRC press, Boca Raton, pp 721-784 [Hi] Cejka J, van Bekkum H (2005) Zeolites and ordered mesoporous materials progress and prospects. Elsevier, Amsterdam, p 157... 

Instead of chemical oxidative polymerization, electropolymerization can also be considered. A recent study shows that slow but efficient electropolymerization is possible if anilinium-exchanged zeolite Y is subjected to oxidative treatment at the electrode-electrolyte interface. Cyclic voltammetric signatures of the polymerization suggest that it occurs mostly through one dimer (p-aminodiphenylamine) which imdergoes oxidative polymerization. Electrochemical polymerization of aniline in zeolite molecular sieves was studied. A zeolite-modified electrode showed shape-selectivity for 12-molybdophosphoric acid. 

Walcarius A. Zeolite-modified electrodes in electroanalytical chemistry. Anal Chim Acta 1999 384(1) 1-16. 

D.R. Rolison, C.A. Bessel, M.D. Baker, C. Seneratne, and J. Zhang, Reply to the Comment on Zeolite-modified Electrodes Intra- versus Extrazeolite Electron Transfer . J. Phys. Chem., 1996, 100, 8610-8611. 

Intensive research is currently being carried out to obtain efficient catalysts for this reaction. Most of the research is devoted to different metal (Pt, in particular)-based materials, but several approaches include porous materials such as Ni-impregnated zeolites, obtained from soaking of zeolites in, for instance, NiSO4 solutions (Abdel Rahim et al., 2006). The performance of gold-zeolite-modified electrodes toward electrocatalytic oxidation of ethanol, an alternative to methanol fuel, has been recently reported by Ouf et al. (2008). 

Bedioui, F., and Devynck, J. 1996. Comment on Zeolite-modified electrodes, intra- versus extrazeohte electron transfer. Journal of Physical Chemistry 100. 8607-8609. 

Li, J.-W., Pfanner, K., and Calzaferri, G. 1995. Reply to Comment on inlrazcohlc electron transport mechanism. The importance of the manner to prepare zeolite-modified electrodes. Journal of Physical Chemistry 99, 12368-12369. 

Senaratne, C, Zhang, J., Baker, M.D., Bessel, C.A., and Rolison, D.R. 1996. Zeolite-modified electrodes Intra- versus extrazeolite electron transfer. Journal of Physical Chemistry 100, 5849-5862. 

Shaw, B.R., Creasy, K.E., Lancycjki, C.J., Sargeant, J.A., and Tirhado, M. 1989. Voltammetric response of zeolite-modified electrodes. Journal of the Electrochemical Society 135, 869-876. 

Zeolite films were also explored for their use in polenliomctric reactions.[93] The authors determined the potentiometric response of zeolite-modified electrodes towards cations in aqueous phase. Three different preparation routes were used for the formation of the zeolite films zeolites Y (FAU), A (LTA) and mordenite (MOR) were pressed into discs, sodalite (SOD) was grown in a free-standing membrane, and for the pressed discs of LTA a secondary growth phase was added in order to heal defects in the pressed discs. The authors could demonstrate size-selective behaviour in these systems, i.e., cations with diameters exceeding those of the zeolite window openings resulted in no detectable potential response. 

The various tunable properties of zeolites have inspired a great variety of concepts in electrochemistry with zeolite-modified electrodes. For example, silver ions inside the zeolite pore system arc not electrochemically active in amperometric detection. Flowever, indirect analyte detection can occur when the analyte causes the removal of silver ions into the solution where they are electrochemically detected.[94] This indirect approach was extended to different copper-exchanged zeolites and demonstrated for the detection of several non-elcctroactive ions including alkali metal, ammonium and calcium.[95] A zeolite-modified electrode (ZME) with high selectivity towards Pb over Cd in cyclic voltammetry was prepared via electrophoretic deposition of zeolite Y, coated with Nafion.[96]... 

In the middle of the last century, the original form of zeolite membranes were synthesized by dispersing the zeolite crystals in polymer membrane matrixes, which were used for gas separation and pervaporative alcohol/water separations. In the last few decades, the researches of polycrystalline zeolite membranes that supported on ceramic, glass, or metal substrates have grown into an attractive and abundant field. Their applications for gas separation, pervaporation, membrane reactors, sensors, low-k films, corrosion protection coatings, zeolite modified electrodes, fuel cells, heat pumps et al. have been wildly explored. In the following text, the applications of supported polycrystalline zeolite membranes for energy and fuels will be presented. 

Mallouk and coworkers explored the electrochemistry and photochemical evolution of hydrogen from water using a zeolite modified electrode. Methylviologen (MV ) was encapsulated in platinized zeolite L powder onto which ZifiTMPyP" ) was externally adsorbed (Figure 106). Taking advantage of the zeolite microstructure in an attempt... 

Walcarius, A. (1999) Factors affecting the analytical applications of zeolite modified electrodes indirect detection of nonelectroactive cations. Anal. Chim. Acta, 388, 79-91. 

Fig. 7.9 (a) Differential pulse voltammograms for a zeolite-modified electrode (ZME) after deposition of 1 ppm Ag" solution for different pre-concentration times (a) 1 (b) 2 (c) 3 (d) 5 (e) 10 min (Reproduced from Ref. [132] with permission of Elsevier), (b) Cyclic voltammograms of 2 X lO " M (a) dopamine and (b) ascorbic acid at (1) pure and (2) 10 wt.% zeolte-modified carbon paste electrodes (Reproduced from Ref. [133] with the permission of Elsevier)... 

Fig. 7.10 (a) Schematic representation of the detection principle for non-electroactive species by means of indirect amperometry at the Cu-doped zeolite-modified electrode (ZME). (b) Ampero-metric responses in flow injection analysis of a Cu -doped zeolite Y carbon paste-modified electrode to successive injections of K samples (a) 5.0 x 10 M, (b) 1.0 x 10 M, (c) 2.5 X 10 M, and (d) 5.0 x 10 M. Flow rate 5 ml/min applied potential —0.25 V. The dimension of the tetrabutylammonium cation (TB A" ) carrier does not allow it to enter the zeolite and, hence, to interfere with K determination (Reproduced fiorn Ref. [147] with the permission of Elsevier)... 

Table 7.6 Examples of the deteimination of chemical species with zeolite-modified electrodes (ZMEs)...

Rolison DR (1990) Zeolite-modified electrodes and electrode-modified zeolites. Chem Rev 90(5) 867-878 Rossinyol E, Prim A, Pellicer E, Arbiol J, Hernandez-Ramirez F, Peiro F, Comet A, Morante JR, Solovyov LA, Tian B, Bo T, Zhao D (2007a) Synthesis and characterization of chromium-doped mesoporous tungsten oxide for gassensing apphcations. Adv Funct Mater 17 1801-1806... 

Walcarius A (1999) Zeolite-modified electrodes in electrochemical chemistry. Anal Chim Acta 384 1-16 Walcarius A (2008) Electroanalytical applications of microporous zeolites and mesoporous (oigano)silicas recent trends. Electroanalysis 20(7) 711-738... 

Figure 8.14 Strategies applied to prepare zeolite modified electrodes. (PDMS polydimethylsilox-ane PS polystyrene PEO polyethylene oxide). Reproduced from reference (106) with permission.

Many different procedures for modification of electrode surfaces by zeolites have been proposed (106). In practice, fabrication of zeolite modified electrodes is complicated by at least two factors first, zeolites are electrically insulating, and second, immobilization of the film by physical or chemical bonding is difficult. Most successful zeolite modification schemes employ composites, where polymers or conductive powders are used as a matrix to support the zeolite. In any successful scheme, electroactive analyte molecules and counter-ions must be able to undergo rapid mass transport within the zeolite-based film. 

Four different strategies for immobilizing zeoUtes on the surface of an electrode can be identified (106). The desired zeoUte can be (1) dispersed within a solid matrix (2) compressed onto a conductive substrate (3) embedded in a polymerie film or (4) covalently anchored. Figure 8.14 outlines these broad approaches and the many different possible electrode structures. Further elaboration on these immobilization schemes can be found in Tables I and II of references (102) and (106), respectively. These references also contain specific examples of preparation procedures for zeolite modified electrodes. 

The unique three-dimensional aluminosilicate crystalline lattice of zeolites gives rise to three intriguing characteristics (104). These characteristics are high cation-exchange capacity, sensitive molecular recognition (size and shape selectivity), and good catalytic activity. These properties give rise to the use of zeolite modified electrodes in sensor development, and electrocatalysis (106). These and other applications are outlined in Table 8.6. More detailed descriptions can be found in recent reviews (7, 96, 102-106), with extensive lists compiled by Rolison (Table 11 in (102)) and Walcarius (Tables 1 and 3 in (105) and Table 1 in (106)). 

Zeolite-Modified Electrodes , in Handbook of Zeolite Science and Technology, S. M. Auerbach,... 

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