Abstract
Palladium nanotubes (PdNTs) were synthesized by templated vapor deposition and investigated for formic acid electrooxidation. Annealed PdNTs are 2.4 times more active (2.19 mA/cm2) than commercial carbon-supported palladium (0.91 mA/cm2) at 0.3 V vs RHE. Bismuth modification improved nanotube performance over 4 times (3.75 mA/cm2) vs Pd/C and nearly 2 times vs unmodified PdNTs. A surface Bi coverage of 80% results in optimal site-specific activity by drastically reducing surface-poisoning CO generation during formic acid electrooxidation. The Bi-modified PdNTs are exceptionally stable, maintaining 2 times the area-normalized current density as Pd/C after 24 h at 0.2 V vs RHE. We attribute the enhanced activity and stability of the nanotube catalysts to the presence of highly coordinated surfaces, mimicking a flat polycrystal while retaining high surface area geometry.
Original language | English |
---|---|
Pages (from-to) | 5154-5163 |
Number of pages | 10 |
Journal | ACS Catalysis |
Volume | 5 |
Issue number | 9 |
DOIs | |
State | Published - Jul 22 2015 |
Keywords
- anodic alumina
- bismuth adatom
- chemical vapor deposition
- formic acid oxidation
- palladium nanotube
- templated synthesis