Janus Pt surfaces derivatized with zwitterionic molecules for oxygen reduction reactions in alkaline and acid electrolytes. (October 2015)

• Record Type: Journal Article
• Authors: Jung, Namgee; Shin, Hyeyoung; Kim, Mansu; Jang, Injoon; Kim, Hyoung-Juhn; Jang, Jong Hyun; Kim, Hyungjun; Yoo, Sung Jong
• Is Part Of: Nano energy. Volume 17(2015:Oct.)
• Page Start: 152
• Page End: 159
• Publication Date: 2015-10
• Subjects: Oxygen reduction reaction -- Zwitterionic molecules -- Spectator ions -- Bifunctional electrocatalyst -- Fuel cell; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2015.08.012
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Direct electrostatic interactions between a charged Pt surface and oppositely charged spectator ions are utilized for the enhancement of oxygen reduction reaction (ORR) activity in both KOH and H3 PO4 solutions. Zwitterionic L-cysteine molecules functionalized on a Pt surface are turned outwards to afford differing surface charges in either alkaline (−) or acid solutions (+). In KOH solution, this leads to the selective impediment of interactions between OH − and K + with the Pt surface through repulsive and attractive interactions of the negatively charged –COO − group of L-cysteine, respectively. In H3 PO4 solution, the phosphoric acid molecule and its anion are effectively captured by the positively charged –NH 3+ moieties of L-cysteine. Behaviors of the spectator species hindering the ORR are systematically controlled through direct electrostatic interactions with the functional groups of L-cysteine in each electrolyte, resulting in a Janus Pt catalyst for superior ORR in both alkaline and acid electrolytes. Graphical abstract: Highlights: Design of fuel cell catalyst for direct non-covalent interaction of spectator species. Pt surface charge transition by functionalization with zwitterionic molecules. Janus Pt catalyst for superior ORR activities in both alkaline and acid electrolytes. Suggestion of novel hybrid catalysts for electrochemical applications.