Concave PtCo nanocrosses for methanol oxidation reaction

Abstract

Concave nanostructures with the high-index facets and highly exposed active sites are desirable in energy conversion technology, whereas the current synthetic strategies still remain challenging. Herein, we report a facile and effective strategy for the synthesis of concave PtCo nanocrosses (PtCo CNCs) with the assist of iminodiacetic acid (IDA). Owing to strong chelation of IDA with metal ions through carboxyl and imino groups, the IDA molecule plays a key role as the structure-directing agent in regulating the cross-like structure. The as-prepared PtCo CNCs are constructed by six arms in three-dimensional space and each protruding arm has concave surface bounded by high-index facets. As an electrocatalyst towards methanol oxidation reaction (MOR), the developed PtCo CNCs exhibit much enhanced specific and mass activity of 3.04 mA cmPt−2 and 692 mA mgPt−1 that are 3.1 and 2.6 times greater than those of commercial Pt black, respectively. The excellent electrocatalytic stability and improved tolerance toward COads are also demonstrated on PtCo CNCs catalyst. The remarkable electrocatalytic performance of PtCo CNCs towards MOR is highly related with their concave surface and high-index facets, as well as synergistic effect between Pt and Co atoms. The facile synthetic strategy and outstanding MOR performance endow PtCo CNCs with great application potential in fuel cells as an anode catalyst.