An enhanced anode based on polymer-coated carbon black for use as a direct methanol fuel cell electrocatalyst

Sluggish methanol oxidation reaction and low durability are the main obstacles for commercialization of direct methanol fuel cells (DMFCs). In this study, we describe the fabrication of 4 different carbon black (CB)-based electrocatalysts for the DMFC by changing the weight ratio between the Pt feed and polymer wrapped carbon support. In all the fabricated electrocatalysts, CB was coated with poly[2,2′-(2,6-pyridine)-5,5′-bibenzimidazole] on which the Pt nanoparticles were deposited, which were further coated with poly(vinylphosphonic acid). We found that a decrease in the Pt particle size produced higher catalytic activity. The electrochemical surface area (ECSA) of the electrocatalyst with the smallest Pt particle size was 120.8±12.0 m²-g_Pt^-1. The mass activity of the methanol oxidation reaction reached 1860 mA-mg_Pt^-1, which is, to the best of our knowledge, the highest value among the recorded catalytic activities of the CB-based electrocatalysts. Moreover, after 100-000 cycles the electrocatalyst displayed only 38-% and 10.7-% decrease in ECSA and methanol oxidation activity, respectively. Such an obtained durability was ≈10 times higher than that of the commercial CB/Pt electrocatalyst. Fuel cell royale: A newly fabricated direct methanol fuel cell electrocatalyst composed of Pt (2.4 nm)/carbon black/polybenzimidazole/poly(vinylphosphonic acid) showed enhancements in durability and catalytic activity.