Metal‐Free Hydrogen‐Bonded Polymers Mimic Noble Metal Electrocatalysts. Issue 25 (17th May 2020)

• Record Type: Journal Article
• Authors: Coskun, Halime; Aljabour, Abdalaziz; de Luna, Phil; Sun, He; Nishiumi, Nobuyuki; Yoshida, Tsukasa; Koller, Georg; Ramsey, Michael G.; Greunz, Theresia; Stifter, David; Strobel, Moritz; Hild, Sabine; Hassel, Achim Walter; Sariciftci, Niyazi Serdar; Sargent, Edward H.; Stadler, Philipp
• Is Part Of: Advanced materials. Volume 32:Issue 25(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-05-17
• Subjects: conducting polymers -- electrocatalysis -- hydrogen bonds -- hydrogen evolution reaction -- polydopamine; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.201902177
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: The most active and efficient catalysts for the electrochemical hydrogen evolution reaction (HER) rely on platinum, a fact that increases the cost of producing hydrogen and thereby limits the widespread adoption of this fuel. Here, a metal‐free organic electrocatalyst that mimics the platinum surface by implementing a high work function and incorporating hydrogen‐affine hydrogen bonds is introduced. These motifs, inspired from enzymology, are deployed here as selective reaction centres. It is shown that the keto‐amine hydrogen‐bond motif enhances the rate‐determining step in proton reduction to molecular hydrogen. The keto‐amine‐functionalized polymers reported herein evolve hydrogen at an overpotential of 190 mV. They share certain key properties with platinum: a similar work function and excellent electrochemical stability and chemical robustness. These properties allow the demonstration of one week of continuous HER operation without notable degradation nor delamination from the carrier electrode. Scaled continuous‐flow electrolysis is reported and 1 L net molecular hydrogen is produced within less than 9 h using 2.3 mg of polymer electrocatalyst. Abstract : Metal‐free polymers that show a selective electrocatalytic activity for hydrogen evolution are presented. The polymers are electrically conducting and functionalized with hydrogen‐bonds, which serve as catalytic sites and perform the hydrogen evolution on par with best‐in‐class noble metals.