(A) study on the formation of block copolymer-templated porous carbon particles and their characteristics as platinum alloy catalysts

Abstract

The activated carbon-supported metal catalysts have received extensive attention and application in the chemical industry. However, despite their popularity, activated carbon does present certain limitations, such as its microporous structure, which hinders efficient mass transfer of molecules during reactions, and the insufficient anchoring sites for the active phase, resulting in uneven dispersion of metal nanoparticles (NPs) on the carbon surface, promoting aggregation and potential leaching of these NPs. As a result, there is a pressing need to develop highly active carbon materials with tunable porosity and surface chemistry to create metal and carbon catalysts with immense industrial prospects. Previously, achieving precise control over the channel nanostructure in mesoporous carbon particles required intricate and costly top-down processing methods, which remains a significant challenge for large-scale production. The advantage of the method using BCP particles is that large-scale synthesis is possible, and particles with uniform size and channel nanostructure can be generated when making BCP emulsions using the membrane emulsification method. This is crucial for various applications, including fuel cells and battery electrodes, as the particle size and structure have a significant impact on performance. Therefore, the BCP emulsion evaporation approach has great potential to achieve precise control over the channel nanostructure within the particles. This doctoral dissertation proposes a facile strategy to fabricate controlled channel nanostructures within porous carbon particles (PCP). In particular, we systematically controlled the exposure of the cylindrical channels on the PCP surface from closed to fully open nanostructures. To investigate the effect of this nanostructure on the activity of the platinum-iron alloy catalyst, the oxidation properties and oxygen reduction reaction of o-phenylenediamine (OPD) were used, and the open channel configuration in PCP promotes mass transfer during the catalytic reaction. We conclude that the open-channel configuration within the PCPs provides a large additional surface, serving as stable deposition sites for the PtFe catalyst and facilitating mass transfer during the catalytic reaction. And we investigate the relationship between channel nanostructure and catalytic performance to provide useful guidelines for PCP structural design.