The field of heterogeneous catalysis, specifically catalysis on bimetallic
surfaces, has seen many advances over the past few decades. Bimetallic
catalysts, which often show electronic and chemical properties that are
distinct from those of their parent metals, offer the opportunity to obtain
new catalysts with enhanced selectivity, activity, and stability. The
oxidation of formic acid is of permanent interest as a model reaction for
the mechanistic understanding of the electrooxidation of small organic
molecules and because of its technical relevance for fuel cell applications.
Platinum is one of the most commonly used catalysts for this reaction,
despite the fact that it shows a few significant disadvantages: high cost
and extreme susceptibility to poisoning by CO. To solve this problem,
several approaches have been used, but generally, they all consist in the
modification of platinum with a second element. Especially, bismuth has
received significant attention as Pt modifier. According to the results
presented in this survey dealing with the effects influencing the formic
acid oxidation it was found that two types of Pt-Bi bimetallic catalysts
(bulk and low loading deposits on GC) showed superior catalytic activity in
terms of the lower onset potential and oxidation current density, as well as
exceptional stability compared to Pt. The findings in this report are
important for the understanding of mechanism of formic acid electrooxidation
on a bulk alloy and decorated surface, for the development of advanced anode
catalysts for direct formic acid fuel cells, as well as for the synthesis of
novel low-loading bimetallic catalysts. The use of bimetallic compounds as
the anode catalysts is an effective solution to overcoming the problems of
the formic acid oxidation current stability for long term applications. In
the future, the tolerance of both CO poisoning and electrochemical leaching
should be considered as the key factors in the development of
electrocatalysts for the anodic reactions.
Nitrogen and Phosphorus Self-Doped Carbon Supported Palladium as Highly Efficient Electrocatalysts for Formic Acid Oxidation
