A highly active, stable and synergistic Pt nanoparticles/Mo2C nanotube catalyst for methanol electro-oxidation

Abstract

Poor electrocatalytic activity and carbon monoxide (CO) poisoning of the anode in Pt-based catalysts are still two major challenges facing direct methanol fuel cells. Herein, we demonstrate a highly active and stable Pt nanoparticle/Mo2C nanotube catalyst for methanol electro-oxidation. Pt nanoparticles were deposited on Mo2C nanotubes using a controllable atomic layer deposition (ALD) technique. This catalyst showed much higher catalytic activity for methanol oxidation and superior CO tolerance, when compared with those of the conventional Pt/C and PtRu/C catalysts. The experimental evidence from X-ray absorption near-edge structure spectroscopy and scanning transmission X-ray microscopy clearly support a strong chemical interaction between the Pt nanoparticles and Mo2C nanotubes. Our studies show that the existence of Mo2C not only minimizes the required Pt usage but also significantly enhances CO tolerance and thus improves their durability. These results provide a promising strategy for the design of highly active next-generation catalysts. Platinum nanoparticles on Mo2C nanotubesact as a stable, highly active catalyst for methanol electro-oxidation, find a binational team led by Chunwen Sun from Institute of Physics, Chinese Academy of Sciences. Methanol electro-oxidation is a critical reaction in direct methanol fuel cells, but conventional methods for catalysing it using Pt-based catalysts loaded on carbon suffer from low activities and CO poisoning of the anode. Now, researchers in China and Canada have discovered that a catalyst produced by depositing Pt nanoparticles on Mo2C nanotubes by controlled atomic layer deposition can overcome both problems. Based on X-ray spectroscopy and microscopy measurements, they attribute this to synergistic effects between the two components. Their results reveal that the presence of Mo2C both reduces the amount of Pt needed (thus lowering costs) and enhances CO tolerance (thereby improving durability), indicating that it is a promising strategy for designing highly active next-generation catalysts. In this paper, we demonstrate a highly active and stable Pt nanoparticle/Mo2C nanotube catalyst for methanol electro-oxidation. Well-dispersed Pt nanoparticles were deposited on Mo2C nanotubes using a controllable atomic layer deposition (ALD) technique. This catalyst showed much higher catalytic activity for methanol oxidation and superior CO tolerance, when compared with those of the conventional Pt/C and PtRu/C catalysts. These results provide a promising strategy for the design of highly active next-generation catalysts.