title: Constant-distance mode SECM as a tool to visualize local electrocatalytic activity of oxygen reduction catalysts.
abstract: Multidimensional shearforce-based constant-distance mode scanning electrochemical microscopy (4D SF/CD-SECM) was utilized for the investigation of the activity distribution of oxygen reduction catalysts. Carbon-supported Pt model catalyst powders have been immobilized in recessed microelectrodes and compared to a spot preparation technique. Microcavities serve as platform for the binder-free catalyst sample preparation exhibiting beneficial properties for constant-distance mode SECM imaging concerning modified surface area and catalyst loading. The integration of the redox competition mode of SECM into the detection scheme of the 4D SF/CD mode is demonstrated for specifically adapting high-resolution SECM experiments to powder-based catalyst preparations.
authors.affiliation: Lehrstuhl für Analytische Chemie; Ruhr-Universität Bochum, D-44780 Bochum ; Sensolytics GmbH, Universitätsstr 142, D-44799 Bochum.
authors.forename: Michaela
authors.initials: M
authors.lastname: Nebel
authors.affiliation: Sensolytics GmbH, Universitätsstr 142, D-44799 Bochum.
authors.forename: Thomas
authors.initials: T
authors.lastname: Erichsen
authors.affiliation: Lehrstuhl für Analytische Chemie; Ruhr-Universität Bochum, D-44780 Bochum.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schuhmann
keywords: SECM; electrocatalysis; oxygen reduction; recessed microelectrodes; redox-competition SECM; scanning electrochemical microscopy; shearforce-based constant-distance mode