Fabrication of platinum electrocatalysts on carbon nanotubes using atomic layer deposition for proton exchange membrane fuel cells

Platinum (Pt) has been synthesized by atomic layer deposition (ALD) onto the surface of multi-layered carbon nanotubes (CNTs) in order to investigate catalytic activity and durability of the ALD-Pt catalyst electrode in proton exchange membrane fuel cells (PEMFCs). Methylcyclopentadienyl-(trimethyl) platinum (MeCpPtMe3) and oxygen serve as precursors at a deposition temperature of 250 °C. One growth mechanism involving two self-limiting reactions is proposed to clarify the decoration of ALD-Pt nanoparticles over the CNT support. The resultant ALD-Pt catalyst displays not only the fairly good electrochemical activity (electrochemically active surface area) but also the stability after potential cycling >1000 cycles. Experimental results also show that the CNTs decorated with the ALD-Pt catalysts exhibit low-equivalent series resistance (∼3.55 Ω), high-power density (∼2.95 kW g Pt−1 at 80 °C) and long-term durability. On the basis of the results, the ALD approach is capable of synthesizing well-dispersed Pt nanoparticles onto CNTs, forming the advanced design of catalyst electrode for PEMFCs.