Continuous Flow Synthesis of Platinum Nanoparticles in Porous Carbon as Durable and Methanol‐Tolerant Electrocatalysts for the Oxygen Reduction Reaction

Abstract

The development and commercialization of direct methanol fuel cells (DMFCs) as energy conversion devices remains a challenge despite their advantages in terms of energy density and energy-conversion efficiency. The bottleneck for the development of DMFCs is mainly caused by the sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode of fuel cells, and the effect of the so-called methanol crossover in state-of-the-art Pt/C electrocatalysts. Herein, we report for the first time an easily scalable continuous flow method based on ultraspray pyrolysis (USP) for the preparation of Pt nanoparticles directly embedded on highly porous carbon spheres. A study on the effect that post-synthesis treatment procedures have on the level of graphitization and catalytic properties is described. Use of USP results in a substantial reduction of the final Pt content with respect to typical Pt/C electrocatalysts, while yielding also excellent durability and tolerance to methanol crossover under acidic conditions. These results demonstrate that the USP method reported herein is a good candidate for its use in the preparation of ORR catalysts in commercial applications.

Layered and two dimensional metal oxides for electrochemical energy conversion

“…The state-of-the-art Pt catalysts for the ORR are also highly susceptible to impurities which makes the Pt materials less stable over time and decreases the material's ability to catalyse the ORR. 44 A viable route around the problems encountered during the ORR and OER is to find low cost, stable and highly…”

Anionic Polymerization of Para-Diethynylbenzene: Synthesis of a Strictly Linear Polymer

“…Homo- and copolymers of p -diethynylbenzene (DEB) as polyarylacetylene resins have additional properties that distinguish them in this class of polymers: good graphitization, high thermal resistance and increased coke residue, which is important when creating carbon-carbon composite materials for aviation and rocket engineering [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Using the DEB polymer, it was proposed to produce composites of carbon nanotubes [ 13 ] and quartz glass [ 14 ], Pt/C electrocatalysts with Pt nanoparticles in highly porous carbon spheres for fuel cells [ 15 ], humidity sensors [ 16 ], and micro-mesoporous meshes with increased adsorption capacity to hydrogen [ 17 ]. A wide variety of initiators are used for polyDEB synthesis, including quite rare and exotic ones [ 1 , 3 , 4 , 5 ].…”

Porous Carbon Microparticles as Vehicles for the Intracellular Delivery of Molecules

“…Particles of variable size can be readily prepared ranging from 200 nm to 1 µm diameter with tunable surface area in the region 500-1,000 m 2 g −1 . The high specific surface makes the materials ideal supports for catalysis (Metz et al, 2015;Dominguez et al, 2018), while the rich functional chemistry of carbon surfaces allows the use of standard routes including bioconjugate techniques to engineer the chemical nature of the surface (Sun et al, 2006;Duffy et al, 2012). These features facilitate the physical entrapment of large quantities of cargo, the covalent conjugation of small molecules or biological species and also the capability of directing delivery through surface modification.…”