Electrocatalytic reduction of carbon dioxide on gold–copper bimetallic nanoparticles: Effects of surface composition on selectivity

Visualizing Ligand-Mediated Bimetallic Nanocrystal Formation Pathways with in Situ Liquid-Phase Transmission Electron Microscopy Synthesis

“…We chose AuCu alloyed nanocrystals as a model system because of their important application as a highly active CO2 electroreduction catalysts. [44][45][46] Prior work has shown that although AuCu alloys are thermodynamically favorable through intermetallic phase formation, [47][48][49][50] it is challenging to synthesize alloyed AuCu nanocrystals with tunable composition by wet chemical co-reduction due to the different reduction kinetics of gold and copper precursors. In this article, we use alloying extent and nanoparticle characteristics as sensitive electron beam damage indicators, where formation of equimolar, unaggregated AuCu alloy nanocrystals indicated metal thiolate complex integrity was preserved during in situ LP-TEM synthesis.…”

“…Ideally, the electron beam exclusively reduces metal precursors and does not drive undesirable side reactions like oxidation of organic capping ligands or nanoparticles. , In this paper, we uncover in situ LP-TEM electron beam synthesis conditions for alloyed bimetallic nanoparticles that preserve the salient chemistry of ex situ flask synthesis (Figure a). We chose AuCu-alloyed nanocrystals as a model system because of their potential application as a highly active CO 2 electroreduction catalyst. ,, While prior work has shown that AuCu alloys readily form as intermetallic phases, − it is challenging to synthesize alloyed AuCu nanocrystals by wet chemical coreduction due to the different reduction kinetics of gold and copper precursors. In this paper, we use alloying extent and nanoparticle characteristics as electron beam damage indicators, where formation of unaggregated AuCu alloy nanocrystals with statistically similar compositions as those formed by ex situ flask synthesis indicates the molecular structure of the precursor complex was preserved during in situ LP-TEM synthesis.…”

In Situ Electrochemical Route to Bromide Anion-Adsorbed Coral-like Porous Silver Microspheres Achieving Highly Selective Electroreduction of CO2 to CO over a Wide Potential Range

“…As liquid-phase products such as formate tend to be produced at high voltages, the absolute amount of liquid-phase products increases with the increase in voltage. Therefore, the electrolyte is used for testing CO 2 ERR at the highest voltages, and it can be inferred that no liquid-phase products are generated at each voltage in the measurements of this study. − FE diagrams corresponding to CO and H 2 production (Figures b and S9) show that over a wide voltage range, the FE of the Ag BACPSs is significantly superior to the rest of the samples and it jumps to 96.5% at lower voltages (−0.4 V), reaching a maximum of 98.7% at −0.6 V. Meanwhile, excellent selectivity is maintained over a wide voltage range; they can maintain an FE of more than 91% from −0.4 to −0.9 V and even more than 96% between −0.4 and −0.7 V. It is difficult to reach this level for both Ag MPs that are similar in size to the microspheres and Ag NPs that are similar in size to the branches inside the microspheres. The excellent selectivity is attributed to the structure of the material with many interpenetrated pores and the modification of the surface of the material by bromide anions.…”

Revisiting The Phase Diagram of Au – Cu Alloy at Nanoscales

“…Gold -Copper (Au-Cu) alloy nanoparticles have attracted considerable interest in nanoscience and nanotechnology, especially as catalysis. They are widely used in the oxidation of carbon monoxide [1], reduction of carbon dioxide [2], selective oxidation of alcohols [3], and other chemical reactions [4,5]. It has been shown that the catalytic efficiency of nanoparticles directly depends on their melting temperatures [6].…”