Simultaneous Mapping of Electrocatalytic Activity and Selectivity via Hybrid Scanning Electrochemical Probe Microscopy.
C Hyun RyuHang RenPublished in: Nano letters (2024)
Nanoscale scanning electrochemical probe microscopy started to elucidate the heterogeneity of electrocatalytic activity at electrode surfaces. However, understanding the heterogeneity in product selectivity, another crucial aspect of interfacial reactivity, remains challenging. Herein, we introduce a method combining scanning electrochemical microscopy (SECM) and scanning electrochemical cell microscopy (SECCM) to enable the spatially resolved mapping of both activity and selectivity in electrocatalysis. A dual-channel nanopipette probe was developed: one channel for activity mapping and the other for product detection with a high collection efficiency (>95%) and sensitivity. Simultaneous mapping of activity and selectivity in the oxygen reduction reaction (ORR) is demonstrated. Combined with colocalized crystal orientation mapping, we uncover the local electrocatalytic performance of ORR at different facets on polycrystalline Pt and Au. The high-resolution selectivity mapping enabled by our method with colocalized structural characterization can provide structure-activity-selectivity relationships that are often unavailable in ensemble measurement, holding promise for understanding key structural motifs controlling interfacial reactivity.
Keyphrases
- high resolution
- label free
- ionic liquid
- mass spectrometry
- gold nanoparticles
- high speed
- reduced graphene oxide
- single molecule
- tandem mass spectrometry
- quantum dots
- molecularly imprinted
- molecular dynamics simulations
- electron transfer
- escherichia coli
- optical coherence tomography
- machine learning
- staphylococcus aureus
- metal organic framework
- cell therapy
- high throughput
- atomic force microscopy
- artificial intelligence
- convolutional neural network
- carbon nanotubes