Dual properties of a hydrogen oxidation Ni-catalyst entrapped within a polymer promote self-defense against oxygen

• Published in: Nature communications Vol. 9; no. 1; pp. 864 - 6
• Main Authors: Oughli, Alaa A., Ruff, Adrian, Boralugodage, Nilusha Priyadarshani, Rodríguez-Maciá, Patricia, Plumeré, Nicolas, Lubitz, Wolfgang, Shaw, Wendy J., Schuhmann, Wolfgang, Rüdiger, Olaf
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28.02.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 639/638/161/893; 639/638/675; 639/638/77/886; Catalysis; Catalysts; Electrodes; ENERGY STORAGE; Humanities and Social Sciences; Insulation; multidisciplinary; Nickel; Noble metals; Oxidation; Polymers; Protective coatings; Science; Science (multidisciplinary); Stability
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-03011-7

The Ni(P 2 N 2 ) 2 catalysts are among the most efficient non-noble-metal based molecular catalysts for H 2 cycling. However, these catalysts are O 2 sensitive and lack long term stability under operating conditions. Here, we show that in a redox silent polymer matrix the catalyst is dispersed into two functionally different reaction layers. Close to the electrode surface is the “active” layer where the catalyst oxidizes H 2 and exchanges electrons with the electrode generating a current. At the outer film boundary, insulation of the catalyst from the electrode forms a “protection” layer in which H 2 is used by the catalyst to convert O 2 to H 2 O, thereby providing the “active” layer with a barrier against O 2 . This simple but efficient polymer-based electrode design solves one of the biggest limitations of these otherwise very efficient catalysts enhancing its stability for catalytic H 2 oxidation as well as O 2 tolerance. Bio-inspired Ni-based molecular catalysts are efficient for H 2 oxidation, but are suffering from the poor stability in the presence of O 2 . Here, the authors develop a strategy to boost greatly their stability by dispersing them in a hydrophobic and redox-silent polymer matrix.