Highly dispersed platinum nanoparticles on graphitic carbon nitride: A highly active and durable electrocatalyst for oxidation of methanol, formic acid and formaldehyde

Abstract Finding efficient electrocatalyst for oxidation of small organic molecules such as methanol (CH 3 OH), formic acid (HCOOH), formaldehyde (HCHO) etc. is essential for the development of their respective direct fuel cells. We report here highly dispersed platinum nanoparticles (PtNPs) on carbon nitride (CN x ) were successfully synthesized by the ultrasound mediated sodium borohydride reduction of H 2 PtCl 6 in presence of CN x nanosheets. This platinum–carbon nitride (Pt/CN x ) composite exhibited superior electrocatalytic activity towards oxidation of CH 3 OH, HCOOH and HCHO in acid media. The mass activity, onset potential, tolerance to carbon monoxide (CO) poisoning and long term durability for the catalytic oxidation of CH 3 OH, HCOOH, HCHO on Pt/CN x catalyst in acid media is much higher than that of commercial Pt/C catalyst. The mass activity of Pt/CN x catalyst at ∼0.64 V (forward scan) is 310 mA/mg Pt which is 2.7 time higher than that of commercial Pt/C for methanol oxidation. The electrooxidation of HCOOH on Pt/CN x occurs via dual mechanism with greatly enhanced oxidation through dehydrogenation pathway in comparison with commercial Pt/C. The mass activity on Pt/CN x at 0.3 V (vs. NHE) is 25 times higher than that of Pt/C for oxidation of HCOOH. The superior catalytic activity and durability of this Pt/CN x catalyst can be attributed to high dispersion of PtNPs and strong catalyst support interaction.