Electrochemical Performance Improvement of the Catalyst of the Methanol Microfuel Cell Using Carbon Nanotubes

In this research, the electrocatalytic activity of platinum-ruthenium nanoparticles on carbon nanotubes and carbon black in methanol oxidation reaction has been investigated. Moreover, the electrochemical performance of a single passive direct methanol fuel cell run by these two different electrocatalysts has been reported. Physical characterization and electrochemical tests reveal the superiority of PtRu on carbon nanotubes. Based on the voltammetry outcomes, it was found that methanol oxidation reaction kinetics has been improved on the nanotube-supported catalyst. The current density of oxidation reaction has increased up to 62% in nanotube sample compared to carbon black-supported one. The electrochemical test results have shown that the carbon nanotubes increase the performance of the microfuel cell by 37% at maximum power density, compared to the carbon black. Moreover, the resistance of the samples supported by carbon nanotubes to poisonous intermediate species has been found 3% more than carbon black-supported one. According to the chronoamperometry test results, it was concluded that the performance and sustainability of the carbon nanotube electrocatalyst show a remarkable improvement compared to carbon black electrocatalyst in the long term.

Development and Application of One-Sided Piezoelectric Actuating Micropump

Three types of one-sided actuating piezoelectric micropumps are studied in this paper. In the first type, one-sided actuating micropump with two check valves can enhance the flow rate and prevent the back flow in suction mode to keep the flow in one direction. Furthermore, the frequency modulator is applied in the micropump to adjust and promote the maximum flow rate higher than 5.0 mL/s. In the second type, valveless micropump with secondary chamber shows that the secondary chamber plays a key role in the application of the valveless micropump. It not only keeps the flow in one direction but also makes the flow rate of the pump reach 0.989 mL/s. In addition, when a nozzle/diffuser element is used in valveless micropump, the flow rate can be further improved to 1.183 mL/s at a frequency of 150 Hz. In the third type, piezoelectric actuating pump is regarded as an air pump in the application of a microfuel cell system, which can increase more air inlet to improve the fuel/air reaction and further increase the performance of fuel cell.