In order to enhance the Pd based anodic catalysts for direct formic acid fuel cells (DFAFCs), the research work includes increasing catalyst activity and preventing CO poison. In this study, various zirconium oxides-m...In order to enhance the Pd based anodic catalysts for direct formic acid fuel cells (DFAFCs), the research work includes increasing catalyst activity and preventing CO poison. In this study, various zirconium oxides-modified multi-walled carbon nanotubes (MWCNTs) were prepared as the supports of Pd catalysts for DFAFCs by adjusting the preparation parameters: metal adding, sintering temperature and atmospheres. The prepared pure zirconia has both monoclinic and tetragonal phases. The addition of MWCNTs depresses the growth of monoclinic phase. A small amount of Pd adding allows both monoclinic and tetragonal zirconia structures to appear again. Pd nanoparticles of 20 wt% synthesized on MWCNTs and tetragonal ZrO2/MWCNTs have similar particle size, while Pd/[Pd:ZrO2/AO-MWCNTs-300Air-900Ar] have more nanoparticles aggregation. The electrochemical surface area can be improved by adding zirconia which implies those zirconia modified Pd catalysts better electrocatalytic performance. By analyzing the maximum current density and the corresponding potential, Pd/AO-MWCNTs are inferred to undergo the formic acid direct oxidation initially. The Pd catalysts modified by tetragonal ZrO2 have higher current density. Those having both tetragonal and monoclinic ZrO2 modified Pd catalysts have lower potential of formic acid oxidation. All the Pd based catalysts with zirconia modification possess better CO resist ability and electrocatalytic activity. Pd/[ZrO2/AO-MWCNTs-300Air-900Ar] and Pd/[Pd:ZrO2/AO-MWCNTs-300Air-900Ar] which catalyze formic acid in direct oxidation path are the two best catalysts.展开更多
Improving catalyst performance by studying the preparation parameters, material structures and analysis methods is important work for catalyst researchers. In this study, Cu-Pt nanocomposites with different metal rati...Improving catalyst performance by studying the preparation parameters, material structures and analysis methods is important work for catalyst researchers. In this study, Cu-Pt nanocomposites with different metal ratios were synthesized on MWCNTs using a polyol method. The structures and morphologies of the nano hybrid catalysts were analyzed by XRD and TEM. The XRD results indicate that Pt and Cu formed a bimetallic solid solution. The average diameters of the Pt and Cu-Pt nanoparticles on MWCNTs were between 3-10 nm and 5-15 nm, respectively. The electrocatalytic behavior of methanol oxidation reactions was investigated by cyclic voltammery （CV）. Cu（20%）/[Pt/MWCNTs（1：4）], which contained an optimal degree of solid solution, enhanced the methanol oxidation to the greatest degree.展开更多
文摘In order to enhance the Pd based anodic catalysts for direct formic acid fuel cells (DFAFCs), the research work includes increasing catalyst activity and preventing CO poison. In this study, various zirconium oxides-modified multi-walled carbon nanotubes (MWCNTs) were prepared as the supports of Pd catalysts for DFAFCs by adjusting the preparation parameters: metal adding, sintering temperature and atmospheres. The prepared pure zirconia has both monoclinic and tetragonal phases. The addition of MWCNTs depresses the growth of monoclinic phase. A small amount of Pd adding allows both monoclinic and tetragonal zirconia structures to appear again. Pd nanoparticles of 20 wt% synthesized on MWCNTs and tetragonal ZrO2/MWCNTs have similar particle size, while Pd/[Pd:ZrO2/AO-MWCNTs-300Air-900Ar] have more nanoparticles aggregation. The electrochemical surface area can be improved by adding zirconia which implies those zirconia modified Pd catalysts better electrocatalytic performance. By analyzing the maximum current density and the corresponding potential, Pd/AO-MWCNTs are inferred to undergo the formic acid direct oxidation initially. The Pd catalysts modified by tetragonal ZrO2 have higher current density. Those having both tetragonal and monoclinic ZrO2 modified Pd catalysts have lower potential of formic acid oxidation. All the Pd based catalysts with zirconia modification possess better CO resist ability and electrocatalytic activity. Pd/[ZrO2/AO-MWCNTs-300Air-900Ar] and Pd/[Pd:ZrO2/AO-MWCNTs-300Air-900Ar] which catalyze formic acid in direct oxidation path are the two best catalysts.
基金the financial support of the Taiwan National Science Council
文摘Improving catalyst performance by studying the preparation parameters, material structures and analysis methods is important work for catalyst researchers. In this study, Cu-Pt nanocomposites with different metal ratios were synthesized on MWCNTs using a polyol method. The structures and morphologies of the nano hybrid catalysts were analyzed by XRD and TEM. The XRD results indicate that Pt and Cu formed a bimetallic solid solution. The average diameters of the Pt and Cu-Pt nanoparticles on MWCNTs were between 3-10 nm and 5-15 nm, respectively. The electrocatalytic behavior of methanol oxidation reactions was investigated by cyclic voltammery （CV）. Cu（20%）/[Pt/MWCNTs（1：4）], which contained an optimal degree of solid solution, enhanced the methanol oxidation to the greatest degree.
