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Comparison of Pt/MWCNTs nanocatalysts synthesis processes for proton exchange membrane fuel cells

Description
Due to the growing concerns on the depletion of petroleum based energy resources and climate change; fuel cell technologies have received much attention in recent years. Proton exchange membrane fuel cell (PEMFCs) features high energy conversion efficiency and nearly zero greenhouse gas emissions, because of its combination of the hydrogen…

Due to the growing concerns on the depletion of petroleum based energy resources and climate change; fuel cell technologies have received much attention in recent years. Proton exchange membrane fuel cell (PEMFCs) features high energy conversion efficiency and nearly zero greenhouse gas emissions, because of its combination of the hydrogen oxidation reaction (HOR) at anode side and oxygen reduction reaction (ORR) at cathode side. Synthesis of Pt nanoparticles supported on multi walled carbon nanotubes (MWCNTs) possess a highly durable electrochemical surface area (ESA) and show good power output on proton exchange membrane (PEM) fuel cell performance. Platinum on multi-walled carbon nanotubes (MWCNTs) support were synthesized by two different processes to transfer PtCl62- from aqueous to organic phase. While the first method of Pt/MWCNTs synthesis involved dodecane thiol (DDT) and octadecane thiol (ODT) as anchoring agent, the second method used ammonium lauryl sulfate (ALS) as the dispersion/anchoring agent. The particle size and distribution of platinum were examined by high-resolution transmission electron microscope (HRTEM). The TEM images showed homogenous distribution and uniform particle size of platinum deposited on the surface of MWCNTs. The single cell fuel cell performance of the Pt/MWCNTs synthesized thiols and ALS based electrode containing 0.2 (anode) and 0.4 mg (cathode) Pt.cm-2 were evaluated using Nafion-212 electrolyte with H2 and O2 gases at 80 oC and ambient pressure. The catalyst synthesis with ALS is relatively simple compared to that with thiols and also showed higher performance (power density reaches about 1070 mW.cm-2). The Electrodes with Pt/MWCNTs nanocatalysts synthesized using ALS were characterized by cyclic voltammetry (CV) for durability evaluation using humidified H2 and N2 gases at room temperature (21 oC) along with commercial Pt/C for comparison. The ESA measured by cyclic voltammetry between 0.15 and 1.2 V showed significant less degradation after 1000 cycles for ALS based Pt/MWCNTs.
ContributorsLiu, Xuan (Author) / Madakannan, Arunachalanadar (Thesis advisor) / Munukutla, Lakshmi (Committee member) / Tamizhmani, Govindasamy (Committee member) / Arizona State University (Publisher)
Created2011
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Performance Guide: Henry Cowell’s Three Irish Legends and Six Ings, and John Cage’s The Perilous Night

Description
This research will explore the compositional approaches of Henry Cowell and John Cage to reveal piano techniques for the practice and performance of selected works. The discussion will focus on Henry Cowell’s Three Irish Legends and Six Ings, as well as John Cage’s The Perilous Night. An important contribution of…

This research will explore the compositional approaches of Henry Cowell and John Cage to reveal piano techniques for the practice and performance of selected works. The discussion will focus on Henry Cowell’s Three Irish Legends and Six Ings, as well as John Cage’s The Perilous Night. An important contribution of Cowell was to further the use of tone clusters, applied in his Three Irish Legends by playing directly with the forearm, fists, and palm. Cowell’s Six Ings employ rhythmic experimentation, particularly in the first, second, and sixth pieces. He also uses tone color to portray specific programmatic features. John Cage greatly advanced the prepared piano from its earliest beginnings, as evidenced significantly in The Perilous Night. The present study will include advice on piano preparation, along with performance challenges and solutions.
ContributorsLiu, Xuan (Author) / Hamilton, Robert (Thesis advisor) / Campbell, Andrew (Committee member) / Rockmaker, Jody (Committee member) / Arizona State University (Publisher)
Created2020