Self-assembly of mixed Pt and Au nanoparticles on PDDA-functionalized graphene as effective electrocatalysts for formic acid oxidation of fuel cells

Abstract

Pt and Au nanoparticles with controlled Pt : Au molar ratios and PtAu nanoparticle loadings were successfully self-assembled onto poly(diallyldimethylammonium chloride) (PDDA)-functionalized graphene (PDDA-G) as highly effective electrocatalysts for formic acid oxidation in direct formic acid fuel cells (DFAFCs). The simultaneously assembled Pt and Au nanoparticles on PDDA-G showed superb electrocatalytic activity for HCOOH oxidation, and the current density associated with the preferred dehydrogenation pathway for the direct formation of CO(2) through HCOOH oxidation on a Pt(1)Au(8)/PDDA-G (i.e., a Pt : Au ratio of 1 : 8) is 32 times higher than on monometallic Pt/PDDA-G. The main function of the Au in the mixed Pt and Au nanoparticles on PDDA-G is to facilitate the first electron transfer from HCOOH to HCOO(ads) and the effective spillover of HCOO(ads) from Au to Pt nanoparticles, where HCOO(ads) is further oxidized to CO(2). The Pt : Au molar ratio and PtAu nanoparticle loading on PDDA-G supports are the two critical factors to achieve excellent electrocatalytic activity of PtAu/PDDA-G catalysts for the HCOOH oxidation reactions.

Graphene based metal and metal oxide nanocomposites: synthesis, properties and their applications

“…419 Several reports appeared on the application of HRG/Pt-Au nanocomposites for the formic acid oxidation (FAO) which suggests that the electrochemical properties of the hybrid material are affected by the preparation method. 420 Zhang el al. reported on enhanced FAO activity of HRG/Pt-Au (20 wt%) nanocomposites prepared by NaBH 4 reduction.…”

Graphene‐Supported Metal Nanostructures with Controllable Size and Shape as Advanced Electrocatalysts for Fuel Cells

“…Similar to the MOR, the ratio of the forward and backward peak currents, I f /I b , can also be used to qualitatively estimate the CO tolerance of the catalyst. Enhanced electrocatalytic activity of formic acid oxidation has been achieved on graphene-supported catalysts compared to commercial Pd/C, Pt/C, or other carbon-material-supported catalysts by engineering the morphology and composition of the materials [12,20,25,[27][28][29][30][31].…”

“…In addition to metal nanoclusters, much work has been done on the synthesis of graphene-supported monometallic (Au [53], Pt [54][55][56][57][58], and Pd [27,59]) or metal alloy (PtPd [33,36,60,61], PtRu [62][63][64], PtAu [12,28,35,65], PdAg [66,67], PtFe [68,69], PtCo [14,70,71], PtNi [72][73][74][75], PtPdAu [76,77]) NPs and their electrocatalytic activities for fuel cells [42]. Among the alloy nanostructures, PtRu NPs have received special attention because of their high catalytic performance as both anodic and cathodic catalysts.…”

Synthesis of PtNi Alloy Nanoparticles on Graphene-Based Polymer Nanohybrids for Electrocatalytic Oxidation of Methanol

“…Poly(diallyldimethylammonium chloride) (PDDA) has recently been used to form the layer-to-layer structure to modify the graphene surface by non-covalent bonding or π-π interaction [17,18]. Moreover, PDDA immobilized on the carbon nanotubes has been demonstrated [19] to enhance water dispersibility of carbon nanotubes.…”

“…Therefore, the addition of transition metal-based catalysts of Ni atom will be considered as a potential alternative owing to their durability and cheaper costs than Ru atom. On the other hand, the enhancement of MOR has been found by carbon-based electrocatalysts, involved the synthesis of electrocatalysts with varied shapes of carbon-based materials supporting, such as C60 nanoparticles, carbon nanotubes, and graphene nanosheets [12][13][14][15][16][17][18][19][20].…”