Boosting methanol electrocatalytic oxidation over palladium nanocrystallines driven by polydopamine-linking Ketjen black and carbon nanotubes

The integration of diverse carbon materials using a suitable “linker” to form a supporting matrix is recognized as an effective strategy for fabricating efficient and durable electrocatalysts for the methanol oxidation reaction (MOR). Herein, we design and fabricate an advanced electrocatalyst consisting of the coupling Ketjen black (KB) with carbon nanotubes (CNTs) by polydopamine-linking anchoring “surface-clean” Pd nanocrystallines (Pd/KB-PDA-CNTs). As an alkaline-MOR electrocatalyst, the fabricated-Pd/KB-PDA-CNTs demonstrates dramatically enhanced electrocatalytic performance, notably superior activity and durability compared to commercial Pd/C. The electrochemical experimental assessments combined with systematic characterizations show that the polydopamine-linking is pivotal significantly to enhance alkaline-MOR electrocatalytic behavior. Briefly, coupling KB with CNTs via polydopamine-linking not only offers plentiful mass/electron/proton-transfer channels, but also introduces affluent functional groups (hydroxyl groups, imine/amine, catechol and benzene rings), which endows abundant reactive sites for nucleating, growing and anchoring Pd nanocrystallines thereby enabling an efficient regulation of the size, morphology, distribution and electronic state for Pd. The implementation of the coupling KB with CNTs by polydopamine-linking indicates that the coupling different types of carbon materials by polydopamine-linking is a promising strategy for rational designing advanced functional materials for application in electrocatalysis and beyond.