Effect of functionalization for carbon molecular sieve (CMS) synthesized using zeolite template on the incorporation of Pt nanoparticle and performance of the electrodes in PEMFC

Abstract

Well-ordered microporous carbon molecular sieve (CMS) with high surface area was successfully synthesized using zeolite Y as a template for the application in polymer electrolyte fuel cells (PEMFC). CMS is noncovalently functionalized with poly (diallyldimethylammonium chloride, PDDA) and loaded with Pt nanoparticles by reducing Pt precursor (H2PtCl6) in ethylene glycol via polyol method. X-ray photoelectron spectroscopy (XPS) analysis indicates that positively charged PDDA has been irreversibly adsorbed onto the hydrophobic surface of CMS via the it-It interaction between the unsaturated C=C contaminants in PDDA chains. TEM images clearly show that the size of Pt nanoparticles deposited on CMS depends on the amount of PDDA and a significant amount of Pt particles has been anchored to the PDDA-functionalized CMS. The BET surface areas of Pt-PDDA-CMSs are inversely proportional to the amount of PDDA. The stability test for Pt-PDDA-CMS was conducted through repeated potential cycling experiment up to 1200 repeated cycles and exhibited much better stability compared to Pt-CMS and commercial Pt/C. It is seen that the higher the PDDA incorporation is, the larger the electrochemical active surface area is after 1200 repeated cycles of operation