Nano‐Intermetallic AuCu₃ Catalyst for Oxygen Reduction Reaction: Performance and Mechanism

Abstract

This paper introduces a new approach for catalyst design using the non-precious metal Cu as one of the catalytic active centers. This differs from previous studies that considered precious metals to be responsible for the catalytic reaction in precious alloys. Intermetallic AuCu3/C nanoparticles with a diameter of 3 nm were developed for the first time, with uniform dispersion and a narrow size distribution. The ca. 3 nm as-synthesised AuCu3/C showed superior catalytic performance for oxygen reduction reactions (ORR) in alkaline solutions, with comparable half-wave potential and 1.5 times mass current density of commercial Pt/C at 0.80 V (vs. reversible hydrogen electrode (RHE)). The advanced catalytic activities are mainly attributed to the synergetic effects of electro-active atomic Au and Cu on the particle surface, in which Cu helps to activate the O2 molecule and Au benefits OH(-) desorption. The excellent durability and methanol tolerance exhibited in alkaline solutions provide another advantage for AuCu3/C to be considered as a potential alternative cathode catalyst in alkaline fuel cells.

Investigation of Electrocatalysts for Selective Reduction of CO2 to CO: Monitoring the Reaction Products by on line Mass Spectrometry and Gas Chromatography

“…The diffraction peaks for Cu 4 Sn/C nanoparticle clearly show a totally different diffraction pattern from that of pure copper or pure tin due to alloy formation, generating the Cu 4 Sn phase. [55][56][57][58] The obtained average crystallite sizes for SnO 2 /C and NiO/C were 5.6 and 4.0 nm, respectively, and for Cu 2 O-Cu/C, Cu 4 Sn/C and Au/C, the values were of 15.7, 32 and 16 nm, respectively. Figures 2a-2e show the representative bright-field (BF)-TEM images for the as-synthesized electrocatalysts.…”

Non‐Pt Nanostructured Catalysts for Oxygen Reduction Reaction: Synthesis, Catalytic Activity and its Key Factors

“…Zhang et al [ 8 ] synthesized a series of Ir-V bimetallic nanoclusters with various constituent ratios, with Ir 2 V clusters topping Ir x V series regarding catalytic activity. [ 83 ] It was observed from XPS spectra that there is very slight difference of Cu 2p spectra between AuCu and AuCu 3 , indicative of no visible charge transfer between Au and Cu, which is at odds with our general knowledge that Au is the most electronegative and electronwithdrawing metal. The d-band coupling arises from the formation of bimetallic catalysts by mixing one metal with higher/ full d-band fi lling with the other one with lower d-fi lling, which is desirable for ORR catalysis.…”

“…[ 81 ] Prior to the reaction, mixed solution of metallic precursors and EG-isopropanol solvent went through mechanical stirring and ultrasonication. [ 83 ] Au segregation on the surface of the two intermetallic catalysts is indicated by red rings of Au atoms in Figure 3 b,f. The resultant Ag 4 Sn nanoparticles exhibited 4-fold and 17-fold factors of improvement in terms of catalytic activity compared to Ag/C and Sn/C, respectively.…”

Porous AgPd–Pd Composite Nanotubes as Highly Efficient Electrocatalysts for Lithium–Oxygen Batteries

“…[ 40 ] The AgPd alloy sheaths act as a highly effi cient catalyst during the reversible absorption and desorption of hydrogen, owing to the combination of geometric and synergistic effects. [38][39][40][41] To the best of our knowledge, however, there is still no report on using porous AgPd NTs as electrocatalyst for Li-O 2 batteries.…”

“…[28][29][30][31][32][33][34][35] Because of a combination of ligand, geometric, and/or ensemble effects, bimetallic catalysts strongly enhance the kinetics of the ORR and OER. [ 8,21,28,32,[36][37][38][39] Therefore, some bimetallic composites with NT structure have been further designed by controlling the reaction process. For example, Ag nanowires coated with AgPd alloy sheaths were synthesized and used for reversible and Pd, as indexed in the XRD Rietveld refi nement results in Figure 1 a-d.…”