Pt-Ru nanoparticles functionalized mesoporous carbon nitride with tunable pore diameters for DMFC applications

Abstract

Mesoporous carbon nitrides (MCN) with different pore diameters are prepared by a nano-hard-templating strategy using SBA-15 with tunable pore diameters as templates through a simple polymerization of carbon tetrachloride (CTC) and ethylenediamine (EDA) as carbon and nitrogen precursors respectively. The prepared materials are functionalized with Pt and Ru nanoparticles in the highly ordered mesochannels which are separated by thick CN walls. The characterization results by XRD, HRSEM, FT-IR, and N2 adsorption reveal that the prepared MCN samples exhibit well-ordered porous structure and possess larger surface area and uniform pore diameter in comparison to other supports studied. MCN with different pore diameters are impregnated with Pt and Ru nanoparticles which are employed as electrodes for direct methanol fuel cells (DMFC). The performance of the Pt-Ru/MCN is compared with that of commercial MWCNT and Carbon Black-Vulcan-72 (CB-V-72). Among the materials studied, MCN-150(Pt-Ru) shows the highest catalytic activity of 65 mA/cm2, which outperforms Pt-Ru/C by more than 30% and has reasonable stability. The DMFC testing of the membrane electrode assembly of these catalysts reveal that the power density of the best catalyst, MCN-150(Pt-Ru) exceeds by more than two times that of the commercial anode catalyst.