Performance Of Mesoporous Carbon Research Articles

Effect of Precipitated Precursor on the Catalytic Performance of Mesoporous Carbon Supported CuO-ZnO Catalysts

As part of concepts for chemical energy storage of excess chemical energy produced from renewable sources, we investigated the performance of CuO/ZnO catalysts supported on mesoporous carbon to convert CO2 hydrogenation to methanol. In this work, mesoporous carbon was used as the catalyst support for CuO-ZnO catalysts. Four catalysts with different precipitated precursors were synthesized and analyzed by N2-physisorption, X-ray diffraction (XRD), thermogravimetric analysis (TG-DTG), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that catalyst CZ-in situ had the highest turnover frequency (TOF) (2.8 × 10−3 s−1) and methanol production rate (0.8 mmol g−1·h−1). The catalysts for co-precipitation of copper and zinc on carbon precursors are more active. Cu/ZnO domains that are accessible to the reactant gas are another reason for the catalysts being active. The Cu-ZnO interface is crucial to methanol catalyst activity.

Influence of Nitric Acid Oxidation on the Supercapacitive Performance of Mesoporous Carbons with Different Pore Symmetries

Two kinds of mesoporous carbons (MPC) with three-dimensional (3D) body-centered cubic (Imm) and 2D hexagonal symmetry (p6m) were synthesized by using triblock copolymer PEO-PPO-PEO (F127) and diblock copolymer polydimethylsiloxane-poly (ethylene oxide) (PDMS-PEO) as co-templates and were further activated by nitric acid oxidation. The electrochemical performances of MPCs and acid-modified MPCs (H-MPCs) electrodes were investigated. After nitric acid modification, the capacitive performances of MPCs were obviously improved. The acid-modified sample with 2D p6m symmetry (H-2D-MPC) exhibited the highest specific capacitance of 237.1 F g-1 in 6 M KOH at the current density of 1 A g-1 and could be a potential candidate for supercapacitors.

Development of PtGe and PtIn anodic catalysts supported on carbonaceous materials for DMFC

Bimetallic PtGe and PtIn catalysts (Ge/Pt and In/Pt molar ratios = 0.33, 17 wt.% Pt loading) were prepared over carbonaceous supports (carbon Vulcan, carbon nanotubes and structured mesoporous carbon). The liquid phase deposition–reduction method by using 0.4 M sodium borohydride as a reducing agent was employed. The electrocatalytic activity for methanol oxidation was compared with a commercial Pt/CV E-TEK catalyst. The onset potential of the CO oxidation was shifted to less positive values for carbon Vulcan and carbon nanotubes supported catalysts and with a smaller effect in the case of mesoporous carbon supported ones. The best electrocatalytic performance was obtained by using carbon Vulcan as support of bimetallic catalysts, followed by carbon nanotubes. The performance of mesoporous carbon as a support was not adequate. PtGe/CV, PtGe/NT and PtIn/CV catalysts displayed the best performance in DMFC. The good performance of these catalysts could be due to the presence of small particle sizes with a narrow distribution, and to geometric effects (observed from different characterization techniques) related to a probable decoration of Ge or In around the small Pt particles.

Influence of the OMCs pore structures on the capacitive performances of supercapacitor

AbstractIn the present study, two mesoporous carbons OMC‐KIT‐6 and OMC‐SBA‐16 were nanocasted using mesoporous silica of KIT‐6 and SBA‐16 as templates and furfuryl alcohol as carbon precursor. Transmission electron microscopy (TEM) and X‐ray diffraction (XRD) characterizations confirmed that the resultant samples are mesoporous carbons, and the as‐prepared OMC‐KIT‐6 has an Ia3d ordered structure, whereas OMC‐SBA‐16 belongs to Im3m space group. The surface area and the average pore size are (1658 m2 g−1 and 3.4 nm) for OMC‐KIT‐6 and (1638 m2 g−1 and 2.9 nm) for OMC‐SBA‐16, respectively. The results of cyclic voltammograms and galvanostatic charge‐discharge tests show that these two mesoporous carbons have excellent capacitive performances. But the difference of capacitive behavior between OMC‐KIT‐6 and OMC‐SBA‐16 may be a result of the difference of pore geometries of these two carbons. In order to find out the function of mesopore in a supercapacitor, we compared the capacitive properties of mesoporous and microporous carbons; the experiment results indicated that these two kinds of carbon exhibit nearly ideal capacitive behavior at low scan rate. When the scan rate is enhanced up to 50 mV s−1 the performance of mesoporous carbon is more stable than microporous carbon. This outcome demonstrated that mesopore plays an important role in forming double layers in the electrode materials. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.