Effect of pretreatment on Pt–Co/C cathode catalysts for the oxygen reduction reaction

Abstract

8035078560Carbon supported Pt and Pt-Co electrocatalysts for the oxygen reduction reaction in low temperature fuel cells were prepared by the reduction of the metal salts with sodium borohydride and sodium formate. The effect of surface treatment with nitric acid on the carbon surface and Co on the surface of carbon prior to the deposition of Pt was studied. The catalysts where Pt was deposited on treated carbon the ORR reaction preceded more through the two electron pathway and favored peroxide production, while the fresh carbon catalysts proceeded more through the four electron pathway to complete the oxygen reduction reaction. NaCOOH reduced Pt/C catalysts showed higher activity that NaBH 4 reduced Pt/C catalysts. It was determined that the Co addition has a higher impact on catalyst activity and active surface area when used with NaBH 4 as reducing agent as compared to NaCOOH.

Nanoporous PtCo and PtNi alloy ribbons for methanol electrooxidation

“…For instance, a variety of Pt alloy nanomaterials has been developed to enhance its MOR activity considering the alloy effect, such as PtCu nanoparticles [7], PtRu nanotubes [8], supported PtRu nanoparticles [9e11], PtAu [12] and PtPd [13] nanoparticles and so on. Recently, non-precious 3d transition metals (referring to the unfilled subshell electrons in the 3d-orbital), such as Fe, Co, and Ni, were found to have great synergistic catalytic effect on the MOR activity of Pt [13e16] besides their remarkably synergistic role on oxygen reduction reaction (ORR) [5]. With the advantages of the activity enhancement and the cost reduction by alloying with the 3d metal, the morphology of these alloy nanomaterials has also attracted great attention by virtue of the structure effect [6].…”

Microfluidic synthesis of platinum nanoparticles supported on reduced graphene oxide, titanium dioxide, and carbon for PEM fuel cells

“…The power density of individual electrocatalysts was significantly improved compared to the past reports on the same electrocatalysts synthesized by other methods. [30][31][32][33] We believe that the improvement in fuel cell performance was due to enhanced EASA of the electrocatalysts that resulted due to the prevention of aggregates and overall lower size (3-15 nm) of Pt nanoparticles.…”

PtCo on continuous‐phase graphene as PEM fuel cell catalyst

“…46,47 Fox and Colon-Mercado synthesized carbon supported Pt and PtCo electrocatalysts for ORR by the reduction of the metal salts in the presence of sodium borohydride and sodium formate. 48 They pointed out that addition of Co increased electrocatalytic activity and active surface area when used with sodium borohydride as a reducing agent as compared to sodium formate. Kumar et al demonstrated sonochemical preparation of carbon supported PtCo/C bimetallic electrocatalysts having particle size smaller than 5 nm.…”