Express-method for Estimation of Electrocatalytic Activity of Oxide Films toward Oxygen Transfer Reactions

Abstract

Oxidation catalysis of organic substances has attracted special attention in recent years due to of their high industrial significance in green and energy chemistry. The implementation of a transition metal-based catalyst in combination with oxygen is an alternative to the traditional procedures. This study justifies the application of amperometric response 'in situ' for estimation of the electrocatalytic activity of metal oxide films, which are known to be promising for oxygen transfer processes. The reaction of electrooxidation of Mn 2+ ions may be termed as a 'marker' for oxygen transfer reactions due to its kinetic features, such as proportionality between the current density and the surface concentration of •OH-radicals. The relative parameter, k ox , has been offered for estimation of the oxidizing capacity of an anode material toward oxygen transfer reaction in reference to platinum oxidizing capacity. k ox value is automatically calculated exactly during electroplating of MnO x as a ratio of the current density of Mn 2+ + 2H 2 O-2e→MnO 2 +4H + reaction on the tested surface to the current density of this reaction on Pt surface. The developed method was tested during the investigation of catalytic activity of MnO x films for electrooxidation of glucose. The parameter k ox was calculated for other anode materials and was analyzed. The application of the new method allows estimating and comparing the catalytic performance toward oxygen transfer reactions of anode materials or of the same material in different modifications, such as nano particles, composites, different compositions etc. The pre-test reduces manifold the time spent for determination of oxidizing capacity of oxides.

Formation of MnO2-based electrodes with high catalytic activity on the surface of ITO for glucose detection

“…The samples were prepared via CV and CA method. (1, 2) pH1_CV_60 (30 cycles), (3,4) pH1_CV_60 (40 cycles), (5,6) pH1_CV_90, (7, 8) pH1_CA_60, (9, 10) pH1_CA_90, (11,12) pH2_CV_60, (13,14) pH2_CV_90, (15, 16) pH2_CA_60, (17,18) pH2_CA_90, (19,20) pH3.5_CV_60, (21,22) pH3.5_CV_90, (23,24) pH3.5_CA_60, (25,26) pH3.5_CA_90. For details, see main text.…”

“…The first conclusion from Figure 4 -the pH of the solution and the method of precipitation have a huge impact on the morphology of the electrodeposited manganese dioxide. [11][12][13][14][19][20][21][22] show the surface of the sediments deposited by the CV method. With this technique, the precipitate is forming and partially dissolved, thus forming active centres.…”

“…By changing such deposition conditions as the potential, concentrations and pH of the electrolyte, it is easy to influence on the structure and composition of thin films of MnO2. The electrocatalytic activity of electrodes depends on these factors [22].…”

Formation of MnO2-coated ITO electrodes with high catalytic activity for enzymatic glucose detection

“…The electrocatalytic activity of electrodes depends on these factors. 25 In this article we report the results of a study of the electrocatalytic activity towards decomposition of hydrogen peroxide of electrodes formed by MnO 2 electroplating at various pH from sulphate electrolytes on the surface of indium tin oxide coated glass (ITO) using several electrochemical techniques. The composition, morphology, and conductivity of the formed films were studied.…”