Facile synthesis of hierarchically porous carbons and their application as a catalyst support for methanol oxidation

Abstract

We report the facile synthesis of hierarchically porous carbons and their application as a catalyst support for methanol oxidation. The honeycomb-like hierarchically porous carbons were synthesized by a facile self-assembly strategy, in which the template/carbon-precursor composite could be prepared in a one-pot approach by directly evaporating the reactant mixture solution of tetraethyl orthosilicate (TEOS) and phenolic resin. This synthesis process is simple and time-saving in comparison with the conventional casting methods. The as-prepared porous texture combines micropores, mesopores and macropores, mainly originating from the carbonized phenolic resin as well as the silica template formed with different sizes. The porous carbons have a large BET surface area of 664.75 m² g⁻¹ and partially graphitized structures. The morphology and porosity of the carbon product can be obviously affected by the corresponding experimental parameters. A preliminary study of the application of the as-prepared hierarchically porous carbons as the support for a Pt catalyst for methanol oxidation is performed. The porous carbon-supported Pt catalyst exhibits higher current density (120.6 mA mg⁻¹) and stability in comparison with the carbon black-supported Pt catalyst. The as-prepared carbons with a hierarchically porous structure can effectively stabilize the Pt particles and alleviate the agglomeration of the particles during the cyclic voltammogram tests, suggesting potential application in the catalysts of direct methanol fuel cells.