Search

Abstract: Here, the design and synthesis of a multispherical cavity carbon (MSCC) material with in situ silica modification and its application as anode catalyst supporter in proton exchange membrane fuel cells (PEMFC) are reported. The synthetic method involves a template procedure, where 10–30 nm sized silica nanospheres coated with polyvinylpyrrolidone (act as the substrate for aniline polymerization. Pyrolysis of the polymer layer and template etching lead to uniformly distributed MSCC materials. Both the pore sizes and the residue silica content in the inner cavities are controllable during the synthesis. It is further demonstrated that this MSCC material can be used as an anode catalyst supporter in PEMFC systems, where its self‐humidification properties result in enhanced durability. The MSCC‐supported anode exhibits only a 5.4% loss of current density and remains at 860 mA cm−2 after 10 h testing under nonhumidified condition, while commercial catalysts lost 25%. This justifies the promising application of MSCC in PEMFC systems. [ABSTRACT FROM AUTHOR]

Abstract: By using different dual-template combinations, four types of mesoporous silica materials with different morphologies were successfully synthesized. A solid-sphere mesoporous (SSM) silica was obtained using a combination of tri-block copolymer (F127) and 1,12-diaminododecane (DADD), but when F127 was substituted with poly(vinylpyrrolidone) (PVP), a leaf-shaped mesoporous (LSM) silica was obtained. In addition, a hollow-sphere mesoporous (HSM) silica was obtained by using a combination of PVP and dodecylamine (DDA), but a cotton-like mesoporous (CLM) silica was obtained using F127 instead of PVP. All four types of synthesized materials were characterized by SEM, TEM, XRD, and N2 adsorption–desorption isotherms, and the results showed that all of them exhibited high surface area, large pore volume, worm-like pore structure, and beautiful shapes. The results of storage experiments revealed that the HSM and CLM showed good adsorption and storage properties. The HSM (the largest pore volume) seemed to have the larger storage capacity when compared to the CLM, albeit CLM had the highest surface area among all. [Copyright &y& Elsevier]

Abstract: By using two non-ionic surfactants, 1,12-diaminododecane and a triblock copolymer surfactant F127, as templates, grape-like solid spheres of super-microporous silica (SMS) with ordered, worm-like pore structures have been successfully synthesized, then characterized by SEM/TEM, XRD, TG/DTA, etc. In a sample synthesized at 70°C, well-formed grape-like spheres with worm-like pores were observed by SEM and TEM. The average pore size is ca. 1.87nm and the specific surface area of the spheres is 865m2/g. The hydrogen storage capacity of the sample Pd/SMS-70-C, prepared by supporting 5wt% palladium on SMS (synthesized at 70°C), is up to 2.56wt% at 1.2MPa hydrogen pressure. [Copyright &y& Elsevier]