Designing methanol tolerant Pt islands at Pd on carbon promoting electrocatalytic oxygen reduction reaction in acidic media

Designing an efficient ORR electrocatalyst with superior methanol tolerance is crucial to fabricate direct methanol fuel cells (DMFC). In this regard, herein, Pt islands at Pd on carbon nanoparticles (Pd 100-x Pt x /C) was synthesized by combining the chemical reduction and galvanic replacement method, where Ag was used as a sacrificial element. The galvanic replacement of Ag by Pt in Pd 100-x Pt x /C was revealed from the absorption spectra with the absence of Ag’s surface plasmon resonance (SPR) peak. XRD patterns endorse the formation of Pt@Pd/C and nanoscale crystallites. The photographic images of TEM demonstrate the formation of Pt islands at Pd on carbon matrix. The XPS spectra corroborate the metallic state of Pt and Pd in Pt 20 @Pd 80 /C. The optimum composition of Pt 20 -decorated Pd 80 on carbon shows enhanced oxygen reduction reaction (ORR) in an acidic media. Moreover, Pt 20 -decorated Pd 80 on carbon electrocatalyst exhibits low activation energy of 27.6 KJ mol -1 and superior tolerance towards methanol oxidation even at higher concentrations (20 M), signposting it as a promising ORR electrocatalyst for DMFC.