Synthesis of platinum-nickel nanoparticles supported by carbon and titanium oxide structures for efficient and enhanced formic acid oxidation

Abstract

In this study, Platinum Nickel (PtNi) nanoparticles was synthesized using the chemical reduction method and functionalized multi-walled carbon nanotube (f-MWCNT) was synthesized by handling multi-walled carbon nanotube (MWCNT) with weak acid using the arc discharge method. To be evaluated in formic acid oxidation, f-MWCNT supported by PtNi (PtNi@f-MWCNT) and titanium oxide (TiO2) supported by PtNi (PtNi@TiO2) catalysts were synthesized using chemical reduction method. The comparison of PtNi, PtNi@f-MWCNT, and PtNi@TiO2 catalysts obtained in the study for formic acid oxidation is presented and their characterizations were carried out by X-ray Diffraction (XRD), Transmission Electron Microscope (TEM), and Fourier Transform Infrared Spectrometer (FTIR). According to TEM results; PtNi, PtNi@f-MWCNT, and PtNi@TiO2 particle sizes were found to be 12.00 nm, 7.37 nm, and 5.38 nm, respectively. According to the CV results obtained for formic acid oxidation, the anodic peak peaks for PtNi, PtNi@f-MWCNT, and PtNi@TiO2 were 61.20 mA.cm−2, 80.17 mA.cm−2 and 65.07 mA.cm−2, respectively. These results showed that the addition of f-MWCNT and TiO2 support exhibited 1.30 and 1.06 times higher electrocatalytic activity for formic acid oxidation and higher resistance to CO poisoning with If/Ib ratios of 0.97 and 1.48, respectively. With the long-term stability tests obtained, it was observed that the f-MWCNT-supported catalyst showed approximately 9 times more current at the end of 5000 s and provided faster charge transfer with EIS. These findings demonstrated that a more cost-effective catalyst with high electrocatalytic activity was synthesized by obtaining f-MWCNTs from MWCNTs using the arc discharge method. It has also been revealed that TiO2 and f-MWCNT supports exhibit very high potential for fuel cell applications.