Overcoming the Instability of Nanoparticle‐Based Catalyst Films in Alkaline Electrolyzers by using Self‐Assembling and Self‐Healing Films. Issue 29 (12th June 2017)

• Record Type: Journal Article
• Authors: Barwe, Stefan; Masa, Justus; Andronescu, Corina; Mei, Bastian; Schuhmann, Wolfgang; Ventosa, Edgar
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 29(2017)
• Page Start: 8573
• Page End: 8577
• Publication Date: 2017-06-12
• Subjects: electrocatalysis -- nanopowder catalyst -- self-assembly -- self-healing films -- water splitting; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201703963
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Engineering stable electrodes using highly active catalyst nanopowders for electrochemical water splitting remains a challenge. We report an innovative and general approach for attaining highly stable catalyst films with self‐healing capability based on the in situ self‐assembly of catalyst particles during electrolysis. The catalyst particles are added to the electrolyte forming a suspension that is pumped through the electrolyzer. Particles with negatively charged surfaces stick onto the anode, while particles with positively charged surfaces stick to the cathode. The self‐assembled catalyst films have self‐healing properties as long as sufficient catalyst particles are present in the electrolyte. The proof‐of‐concept was demonstrated in a non‐zero gap alkaline electrolyzer using NiFe‐LDH and Ni x B catalyst nanopowders for anode and cathode, respectively. Steady cell voltages were maintained for at least three weeks during continuous electrolysis at 50–100 mA cm −2 . Abstract : Getting particular about films : Stable nanoparticle‐based catalyst films for alkaline electrolyzers are formed in situ while the system is running. Pre‐synthesized catalyst powders are directly added to the electrolyte forming a suspension which is continually pumped through a running electrolyzer leading to self‐assembly of catalyst films driven by electrostatic forces.