| Summary: | 碩士 === 元智大學 === 化學工程與材料科學學系 === 103 === In this study, we synthesized pyridine-polybenzimidazole (PyPBI) for wrapping multi-wall carbon nanotubes (MWCNTs) and immobilizing platinum (Pt) nanoparticles on the surface of the PyPBI wrapped MWCNTs (PyPBI-CNTs). The Pt/PyPBI-CNT, dimethyl acetamide (DMAc), and LiCl mixture catalyst ink solution was used for fabricating catalyst layer (CL) of polybenzimidazole (PBI) membrane electrode assembly (MEA) for high temperature fuel cells. PyPBI was synthesized from 3, 3-diaminobenzidine (DAB) monomer and 2,6-pyridinedicarboxylic acid (PyDA) monomer. The repeat unit of PyPBI chemical structure consists of one more –N: coordinating site than that of PBI, which provides PyPBI high capacity to coordinate with phosphoric acid (H3PO4), leading CLs to have better proton conductivity than those prepared from Pt/C (Pt on carbon powder supports without wrapping with polymer films). The -N: coordinating sites of PyPBI also helps Pt4+ ions immobilizing on the surfaces of PyPBI-CNTs. To study effect of the PyPBI film thickness of the PyPBI-CNT support on the fuel cell performance, we prepared PyPBI-CNTs by impregnating MWCNT in 0.2-0.8 mg/mL PyPBI/ N,N-dimethylacetamide (PyPBI/DMACs) solutions. The morphologies and Pt particle sizes of Pt/PyPBI-CNT were investigated using a high resolution transmission electron microscopy (HRTEM) and an X-ray diffractometer (XRD). The results showed that the present Pt/PyPBI-CNT composed of a PyPBI film thickness of ~2 nm, a Pt loading of ~40 wt.% and Pt particle sizes of ~3-4 nm.
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