Tailor‐Made Charged Catechol‐Based Polymeric Ligands to Build Robust Fuel Cells Containing Antioxidative Nanoparticles

Abstract

Cerium oxide nanoparticles (CNPs) are investigated as radical scavengers to increase the durability of polymer electrolyte membrane fuel cells (PEMFCs). However, the practical application of CNPs in PEMFCs is hindered by the low stability of the CNPs during cell operation and the low compatibility of the CNPs with PEM. In this study, as effective antioxidants for PEMs, surface‐engineered CNPs, passivated with dopamine‐based copolymer ligands containing multidentate catechol pendant groups (CNP@DPLs), are reported. The DPLs provide enhanced colloidal and chemical stability in acidic and radical environments, thanks to the robust catechol binding groups and polymer backbone shielding. It is highlighted that they also improved the redox cycling ability of the CNPs, with catechol's additional radical scavenging. Using the CNP@DPLs as a model system, the effect of surface charge is also examined. Negatively charged sulfonic acid‐functionalized CNPs (CNP@DSAs) exhibit the highest compatibility with PEMs. Coherently, the CNP@DSA‐based reinforced composite membrane (CNP@DSA‐RCM) shows the lowest disintegration rate in Fenton's test. The PEMFC based on the CNP@DSA‐RCM outperforms previously reported antioxidant‐based PEMFCs. Importantly, while the pristine PEMFC and Ce salt‐based one undergoes degradation after 40 h, the CNP@DSA based PEMFC retains its performance even after 100 h.

Amine-assisted catechol-based nanocoating on ultrasmall iron oxide nanoparticles for high-resolution T1 angiography

“…S11 in the ESI † ), the AANC surface modification method can be applied to highly uniform and various nanocrystals synthesized in high-boiling point organic solvents for bio and electronic applications. 27 …”

“…Recently, we reported that an amine-assisted catechol-based nanocoating (AACN) provides a molecularly smooth and robust coating layer on metal oxide substrates and nanoparticles. 26,27 In the AACN mechanism, the key roles of separated amine in AACN are enhancement of catechol adhesion, suppression of polymerization derived from catechol, and additional stabilization through an in situ generated catechol-amine adduct. Therefore, the detachment of catecholic ligands from NPs by iron ion catalyzed oxidation of catechol on the surface of Fe 3+ rich iron oxides including 3 nm-sized IONPs can be overcome by the method during the coating process.…”

Ceria Tubular Nanoarchitecture Antioxidants Achieve Sustainable Fuel Cell Devices Via Tuning the Oxophilicity of Pt Catalytic Surfaces and Radical Scavenging

“…Importantly, we also confirmed the outstanding antioxidation efficacy of CeO x NT by demonstrating the remarkable durability of the Pt/C + CeO x NT cathode. To evaluate PEMFC durability, we subjected the cathodes to a 100-hour OCV-holding durability test, which simulates a harsh acidic environment with the rapid formation of radical species [16,41,42]. and e) were 93 % and 94 %, respectively, significantly higher than those of the pristine Pt/C cathode (74 % and 78 %).…”