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Title:	Kajian prestasi nanomangkin PtRuFeNi/MWCNT untuk anod sel fuel metanol langsung (SFML)
Authors:	Sahriah Basri ( P56298)
Supervisor:	Siti Kartom Kamarudin, Prof. Dr.
Keywords:	Mangkin dwilogam Sel fuel metanol langsung Multi-lapisan nanotiub karbon Dissertations, Academic -- Malaysia Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	6-Jul-2015
Description:	Mangkin dwilogam PtRu menjanjikan mangkin anod untuk pengkomersialan Sel Fuel Metanol Langsung (SFML). Walau bagaimanapun, kadar tindak balas SFML yang rendah menjadi kekangan yang ketara kepada penurunan prestasi dan kuasa SFML. Justeru itu, objektif utama kajian ini adalah meningkatkan prestasi SFML dengan menambahkan bahan logam nikel (Ni) dan ferum (Fe) serta mengurangkan kos mangkin SFML. Selain daripada itu, multi-lapisan nanotiub karbon (MWCNT) digunakan bagi meningkatkan keluasan aktif dan memperbaiki prestasi mangkin. Selain itu, struktur mangkin dianalisis menggunakan perisian Material Studio dari Accelrys modul DMol3 dan keputusannya dibandingkan dengan ujikaji makmal. Kajian ini juga menilai penggunaan teori fungsi ketumpatan untuk pengiraan tenaga penjerapan, tenaga bebas, frekuensi getaran, dan jumlah ketumpatan cas elektronik. Penghomogen ultrasonik digunakan bagi menghasilkan mangkin sebagai perbandingan dengan kaedah konvensional menggunakan kaedah pengacauan. Teknik analisis seperti penyebaran tenaga sinar-X spektrometri (EDX), pembelauan sinar-X (XRD) dan bidang pelepasan imbasan mikroskop elektron (TEM) telah digunakan untuk pencirian parameter kinetik mangkin hibrid. Kitaran voltammetri (CV) telah digunakan untuk mengkaji kesan penambahan Fe dan Ni sebagai mangkin terhadap kinetik tindak balas. Tenaga ikatan bahan tindak balas dan produk dibandingkan untuk menentukan tenaga kinetik dan keupayaan semasa pengoksidaan metanol. Hasil daripada analisis TEM menunjukkan bahawa nano zarah PtRu (2-5 nm) tersebar dengan sekata pada MWCNT. Ia juga mengesahkan bahawa penghomogen ultrasonik menyebarkan zarah yang lebih seragam berbanding pengacau konvensional. Dalam kajian ini, PtRuFeNi/MWCNT berjaya meningkatkan kinetik tindak balas sebagai mangkin anod untuk SFML berbanding PtRu/MWCNTs. Penambahan logam mulia Fe dan Ni boleh mengurangkan kos mangkin SFML sebanyak 40% disamping mengekalkan prestasi sel. Akhir sekali, model molekul membuktikan bahawa gabungan Fe dan Ni dengan PtRu mempunyai potensi untuk meningkatkan prestasi mangkin anod SFML kerana mempunyai tenaga penyerapan yang rendah kerana kehadiran ion Fe dan Ni telah meningkatkan ketumpatan elektron.,Bimetallic PtRu catalysts is promising anodic catalysts for the commercialisation of direct methanol fuel cells (DMFC). However, slow reaction kinetics is a significant limitation that reduces the performance and power output of DMFCs. Therefore, the main objective of this study is to improve the performance of PtRu catalysts by adding metals such as nickel (Ni) and iron (Fe) and to reduce the cost of catalysts for DMFC. Moreover, multi-walled carbon nanotubes (MWCNTs) are used to increase the active area of the catalyst and improve the catalyst performance. Besides, the nano-catalyst structures are analysed using Materials Studio DMol3 , and the results are compared with experimental results. This study also evaluates the use of density functional theory for calculating the adsorption energy, free energy, vibrational frequencies, and total electronic charge density. An ultrasonic homogeniser was used to prepare catalysts, as opposed to a conventional stirring procedure. Electrochemical analytical techniques such as energy dispersion X-ray spectrometry (EDX), X-ray diffraction (XRD) and transmission electron microscopy (TEM) are used to characterise the kinetic parameters of the hybrid catalyst. Cyclic voltammetry (CV) is used to investigate the effect of adding Fe and Ni to the catalyst on reaction kinetics. The binding energies of reactants and products are compared to determine the kinetics and potential surface energy of methanol oxidation. The results from TEM analysis indicated that well-dispersed nanoscale (2–5 nm) PtRu particles are formed on the MWCNTs. It was also confirmed that ultrasonic homogenisation presents a more uniform particle distribution compared to conventional stirring. In this study, PtRuFeNi/MWCNTs improved the reaction kinetics of anode catalysts for DMFC compared to PtRu/MWCNT. The addition of noble metals could reduce the cost of catalysts for DMFC by 40% while maintaining performance. Finally, the molecular modelling proves that the combination of iron and nickel with PtRu has the potential to improve the performance of the anode catalyst of DMFC due to the lower calculated adsorption energies and the presence of Fe and Ni, which increase the electron density.,Ph.D.
Pages:	162
Call Number:	TK2931.S237 2015 3 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Fuel Cell Institute / Institut Sel Fuel

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