Platinum decorated hierarchical porous structures composed of ultrathin titanium nitride nanoflakes for efficient methanol oxidation reaction

摘要

Alloying Pt electrocatalysts with the second transition metal (e. g., Fe, Co, Ni and Cu) is an effective strategy to boost the methanol oxidation reaction (MOR) and simultaneously reduce the catalyst cost for the direct methanol fuel cells. However, the durability issues caused by the leaching of the transition metals for prolonged time and carbon corrosion hinder the practical applications of the Pt alloys. Herein, for the first time, a facile and robust strategy is developed to synthesize titanium nitride and copper doped titanium nitride with porous and hierarchical tubular structures (labeled as TiN NFs and Ti0.9Cu0.1N NFs, respectively). When used as the Pt support, both of Pt/TiN NFs and Pt/Ti0.9Cu0.1N NFs exhibit much enhanced activity and durability compared with the commercial Pt/C catalyst. The experimental data confirms that the leaching of the transition metal can be significantly impeded by this strategy while their advantageous properties that favors MOR activity for the Pt based catalysts are maintained. This work opens a new path for maximizing the MOR activity and stability by introducing porous binary transition metal nitride as the Pt support, which integrates the advantages of high stability, co-catalysis and doping effects. (c) 2018 Elsevier Ltd. All rights reserved.