Tailoring the morphology of Pt₃Cu₁nanocrystals supported on graphene nanoplates for ethanol oxidation

Abstract

In the search for alternatives to conventional Pt electrocatalysts, we synthesized a series of graphene nanoplate (GNP)-supported Pt3Cu1 nanocrystals (NCs), possessing almost the same composition but different morphologies to probe their electrochemical properties as a function of morphology for the ethanol oxidation reaction. The morphology of the Pt3Cu1 catalysts could be systematically evolved from dendritic (D-Pt3Cu1/GNPs) to wire-like (W-Pt3Cu1/GNPs) and spherical (Pt3Cu1/GNPs) by only varying pH of the reaction solution. The as-prepared Pt3Cu1 catalysts were subsequently characterized using a suite of techniques including transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray photoelectron spectroscopy (XPS) to verify not only their morphologies and chemical compositions but also the incorporation of Cu into the Pt lattice, as well as physical structure and integrity. Gratifyingly, the three Pt3Cu1 catalysts exhibited superior electrocatalytic properties for the ethanol oxidation compared to the monometallic Pt/GNPs and Pt/C-JM (Johnson Matthey), with the activities, durabilities and anti-poisonous abilities following the order Pt3Cu1/GNPs < W-Pt3Cu1/GNPs < D-Pt3Cu1/GNPs.

Rutile Ti0.9Ir0.1O2‐Supported Low Pt Loading: An Efficient Electrocatalyst for Ethanol Electrochemical Oxidation in Acidic Media

“…The negative shift of the Pt binding energy of the as‐obtained rutile Ti 0.9 Ir 0.1 O 2 ‐supported Pt electrocatalyst indicated the electron transfer from the noncarbon Ti 0.9 Ir 0.1 O 2 nanosupport to Pt nanocatalyst, which has also been reported for Pt anchored on other doped metal oxides, [ 4,5,13,14,17–19,35 ] resulting in the modification of the electronic structure and the downshift of the d‐band center of the Pt. [ 6,7,36,37 ] According to the previous studies, [ 6,13,36,38–43 ] the downshift of the d‐band center of the Pt could reduce the binding strength of the adsorbed CO‐like species that produced on the surface of the as‐prepared 15.5 wt% Pt/rutile Ti 0.9 Ir 0.1 O 2 electrocatalyst in acidic and facilitate to react with the adsorbed OH which is the active oxygen species for ethanol electrochemical oxidation and thus the electrochemical performance of the as‐obtained rutile Ti 0.9 Ir 0.1 O 2 ‐supported low Pt‐loading electrocatalyst toward ethanol electro‐oxidation could be significantly enhanced. [ 7,36,44 ]…”

“…[ 4,5 ] Platinum (Pt) has been ubiquitously used in DEFCs because of the moderate activity for the cleavage of C—C bonds arising from their distinct electronic structure. [ 6 ] Apart from the high cost and scarcity, however, the Pt metal is easily poisoned by CO or other carbonaceous species, which are formed and strongly adsorbed on the active platinum sites leading to the rapidly deteriorated activity. [ 7,8 ] What's more, the serious electrochemical corrosion and exceedingly weak metal–support interaction in the conventional Pt/C catalyst cause the detachment/dissolution and Ostwald ripening leading to the electrocatalyst degradation and thus the decreased lifetime of the fuel cell systems under harsh fuel cell operation.…”

Surface Compositions of Oxide Supported Bimetallic Catalysts: A Compared Study by High‐Sensitivity Low Energy Ion Scattering Spectroscopy and X‐Ray Photoemission Spectroscopy

“…PtCu alloy is one of the most common alloy catalysts in heterogeneous catalysis and electrocatalysis . The PtCu alloy nanoparticles were synthesized by a solvothermal method: 4.0 mg of Pt(acac) 2 and 8.0 mg of Cu(acac) 2 were dissolved in 3.0 mL of DMF under ultrasonication.…”

Well‐Defined Platinum Surfaces for the Ethanol Oxidation Reaction

“…In our opinion, this work is of great relevance because of the incorporation of Cu in the cubic structure of the noble metals without perturbing the structure of the NPs, which allows not only higher activities but also a cheaper catalyst. However, although many authors have synthesized polycrystalline NPs with different shapes (nanoflowers, nanorings, nanodendrites, nanogarlands…) [83][84][85][86][87][88][89][90][91][92] to be used in the EOR, there are not works using metal NPs enclosed predominantly by high-index facets supported on materials with a well-defined nanoarchitecture.…”