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Simultaneous Mapping of Oxygen Reduction Activity and Hydrogen Peroxide Generation on Electrocatalytic Surfaces
Author(s) -
Kolagatla Srikanth,
Subramanian Palaniappan,
Schechter Alex
Publication year - 2019
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201900656
Subject(s) - scanning electrochemical microscopy , electrochemistry , hydrogen peroxide , catalysis , glassy carbon , electrode , pyrolytic carbon , materials science , electrocatalyst , highly oriented pyrolytic graphite , chemical engineering , nanoparticle , nanotechnology , chemistry , cyclic voltammetry , scanning tunneling microscope , pyrolysis , organic chemistry , engineering
Electrochemical scanning probe microscopies have become valuable experimental tools, owing to their capability of capturing topographic features in addition to mapping the electrochemical activity of nanoscale oxygen reduction catalysts. However, most scanning probe techniques lack the ability to correlate topographic features with the electrochemical oxygen reduction and peroxide formation in real time. In this report, we show that it is indeed possible to construct high‐resolution catalytic current maps at an electrified solid–liquid interface by placing a specially made Au‐coated SiO 2 Pt atomic force microscopy and scanning electrochemical microscopy (AFM–SECM) dual electrode tip approximately 4–8 nm above the reaction center. The catalytic current measured every 16 nm and high collection efficiency (≈90 %) of the reverse current of peroxide byproducts was also demonstrated with the help of the dual electrode tip. Simultaneous oxygen reduction and intermediate peroxide oxidation current mapping was demonstrated using this Au‐coated SiO 2 Pt probe on two model surfaces, namely highly oriented pyrolytic graphite and Pt nanoparticles (NPs) supported on a glassy carbon surface.