Preparation of Pt-Catalyst by Poly(p-phenylenediamine) Nanocomposites Assisted by Microwave Radiation for Proton Exchange Membrane Fuel Cell

Abstract

The Pt elements are prepared via the redox reaction with microwave (MW) irradiation in the presence of poly(p-phenylenediamine) (PpPD) which is polymerized on XC72 carbon matrix (PpPD/XC72), behaving as reducing agent. The free primary amines of PpPD are actually converted (oxidized) to secondary ones (5,10-dihydrophenazine) after MW irradiation. Transmission electronic microscopy (TEM) micrographs reveal the prepared Pt nanoparticles are well-dispersed on the carbon matrix like commercial Pt-implanted carbon nanocomposite (Pt/C). From the residue weights of thermogravimetric analysis (TGA) thermograms of Pt-loaded PpPD/XC72 (PpPD/XC72-Pt-MW), more Pt (18.49 wt %) nanoparticles are implanted on PpPD/XC72 composite. The Pt-implanted wt % on PpPD/XC72 matrix is just slightly lower than that of commercial Pt/C (22.30 wt %). The Pt-catalyst supports of PpPD/XC72-Pt-MW illustrate typical cyclic voltammograms (C-V) of Pt-catalyst, including significant Pt–H oxidation and Pt–O reduction peaks. The electrochemical active surface area of PpPD/XC72-Pt-MW is found to be as high as 60.1 m2 g-1. Max. number of electron transfer during oxygen reduction reaction (ORR) approaches 3.83 for PpPD/XC72-Pt-MW, higher than that of commercial Pt/C (3.62). Single cell based on PpPD/XC72-Pt-MW demonstrates much higher specific max. power density to be 34.6 mW cm-2 Pt, higher than that single cell prepared with commercial Pt/C electrode (30.6 mW cm-2 Pt).

Cobalt-Doped Carbon Nitride Frameworks Obtained from Calcined Aromatic Polyimines as Cathode Catalyst of Anion Exchange Membrane Fuel Cells

“…Therefore, the reduction reactions for preparing Pt nanoparticles are usually carried out in the presence of conducting carbon black (CB), and this results in the so-called Pt/C products [1][2][3][4][5]. To avoid the residue of metal ions from the inorganic reducing agent, some amine-based organic compounds behave as reducing agents during Pt nanoparticle preparation through hydrothermal [6][7][8], microwave-assisted heating [9,10], or calcination [11]. However, the bulk conductivity of the Pt nanoparticle implanted matrix will be low if the implanted matrix is made of nonconducting carbon materials.…”

Cobalt-Based Cathode Catalysts for Oxygen-Reduction Reaction in an Anion Exchange Membrane Fuel Cell

“…Consequently, reduction reactions from the Pt ions to Pt nanoparticles are usually carried out in the presence of conductive CBs, leading to Pt/C [ 1 , 2 , 3 , 4 ]. For convenience, certain amino organic chemicals could also behave like reducing agents to prepare Pt nanoparticles by hydrothermal methods [ 5 , 6 , 7 ], microwave-assisted heating [ 8 , 9 ], or often calcination [ 10 ]. However, to improve the electron transport ability (conductivity) of Pt-nanoparticles deposited on non-conductive carbonaceous substrates, calcination in the absence of air is required to convert most of the sp3-carbon substrates into the conjugated sp2-carbon system (more aromatic structures).…”

Platinum-Containing Nanoparticles on N-Doped Carbon Supports as an Advanced Electrocatalyst for the Oxygen Reduction Reaction

“…Recent research has shown that nitrogen doping of a carbon support makes it possible to create additional oxygen electroreduction active sites (surface fragments containing nitrogen atoms in pyrrole and pyridine). First of all, this has a positive effect on the activity of platinum-free and platinum-carbon catalysts in alkaline media [34][35][36][37]. The presence of nitrogen-containing groups on the support surface can also improve the uniformity of the platinum nanoparticles' distribution during the wet synthesis of Pt/C catalysts [38].…”