Oxygen Electroreduction on Catalysts Containing Platinum Deposited on Carbon Nanotubes Modified by O, N and P Atoms

Abstract

Platinum placed on scattered materials has been the most popular catalyst for generating cathodes for a variety of electrochemical power sources. The purpose of this research is to look into the effect of O, N, and P atoms on the structural, electrocatalytic, and corrosion properties of as-synthesised monoplatinum catalysts. The examined Pt/CNTmod catalysts demonstrated enhanced electrochemically active platinum surface area and electrical conductivity, as well as increased catalytic activity in alkaline electrolytes during the oxygen reduction reaction (ORR). The half-wave potential reaches 0.89 V for nitrogen-doped and 0.88 V for phosphorus-doped CNTs, which is comparable to a commercial catalyst. The increased properties of Pt/CNT catalysts are explained by changes in the composition and amount of groups produced on the CNT surface, as well as their electronic structure. Pt/CNTHNO3+N and Pt/CNTHNO3+NP are the most promising catalysts for use as cathode materials in alkaline medium based on the sum of the major properties. The influence of the platinum mass (10, 20, 40, 60 wt %) on the stability, electrochemical characteristics and the reaction path of ORR in an alkaline electrolyte has been studied. The highest selectivity in ORR to water is observed for catalysts synthesized on nitrogen-doped CNTs and increases due to the growth of the Pt surface on the electrode. The presence of hydrogen peroxide and a decrease in stability are observed at a low content of platinum. Thus, according to the totality of the results of this study, catalysts with 60 and 40 wt. % Pt/CNTNaOH+N, as well as Pt/CNTHNO3+N and Pt/CNTHNO3+NP are the most promising catalysts for alkaline fuel cells.