Degradation of platinum electrocatalysts for methanol oxidation by lead contamination

Platinum exhibits high electrocatalytic activity toward various reactions but might be poisoned by some species. This communication reports a new finding that the electrocatalytic activity of platinum for methanol oxidation will be largely lost in a lead-contaminated environment. This activity loss is demonstrated in an electrochemical cell using a lead counter electrode for measuring the activity of platinum electrode towards methanol oxidation. The recorded methanol oxidation current in this cell is significantly decreased compared with that using a platinum counter electrode. The possible mechanism is related to the adsorption of trace lead ions from the lead counter electrode, as confirmed by comparing the calculated binding energies of platinum and lead ions with oxygen ion. This report is of great importance for reliably designing and efficiently managing direct methanol fuel cells, because trace lead might be present in various components in the fuel cell systems or in air and attention should be paid to its negative effect. (c) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

Platinum has high electrocatalytic activity but can be poisoned by certain substances. This study reveals that platinum loses its electrocatalytic activity for methanol oxidation in the presence of lead contamination. The decrease in activity is demonstrated by comparing methanol oxidation current using a lead counter electrode versus a platinum counter electrode. The mechanism is attributed to the adsorption of trace lead ions from the lead counter electrode, as confirmed by calculating binding energies. This report is important for the design and management of direct methanol fuel cells, considering the potential negative effect of trace lead contamination.