Low-Pt Octahedral PtCuCo Nanoalloys: “One Stone, Four Birds” for Oxygen Reduction and Methanol Oxidation Reactions

Abstract

To find a low-Pt electrocatalyst that is functionally integrated and superior to the state-of-the-art single-Pt electrocatalyst is expectedly a challenge. We have in this study found that the reactivity of the oxygen reduction reaction (ORR) and the methanol oxidation reaction (MOR), in both acidic and alkaline electrolytes (viz., four halfcell reactions), can be modified and greatly enhanced by the electronic and/or synergistic effects of a low-Pt octahedral PtCuCo alloy. For the ORR, the mass activity (MA) of Pt 0.23 Cu 0.64 Co 0.13 /C in an acidic or alkaline electrolyte was 14.3 or 10.7 times that of the commercial Pt/C. For the MOR, the MA of Pt 0.23 Cu 0.64 Co 0.13 /C in an acidic or alkaline electrolyte was 7.2 or 3.4 times that of the commercial Pt/C. In addition, Pt 0.23 Cu 0.64 Co 0.13 /C exhibited an increased durability and CO tolerance, as compared with the commercial Pt/C. Density functional theory calculations demonstrated that the PtCuCo(111) surface can effectively optimize the O* binding energy. This work has successfully shown an example of how both acidic and alkaline ORR and MOR activities can be significantly synchronously enhanced.

Electronic Structure Effect of PtCo Alloy with Adjustable Compositions for Efficient Methanol Electrooxidation

“…Currently, platinum-based alloys are well recognized as high-performance electrocatalysts for accelerating the sluggish MOR process. − However, the limited storage capacity and exorbitant cost of platinum continue to impede the widespread adoption of fuel cells. Moreover, Pt-based MOR catalysts encounter obstacles such as poor utilization efficiency, limited durability, and the harmful effects of surface intermediates like CO. − Consequently, the pivotal challenge in catalyst development for fuel cells lies in enhancing the utilization and effectiveness of Pt. − …”

Abundant Exterior/Interior Active Sites Enable Three-Dimensional PdPtBiTe Dumbbells C–C Cleavage Electrocatalysts for Actual Alcohol Fuel Cells

“…The bands at 1408 cm –1 are related to CO 3 2– , and CO 2 is detected from 2345 cm –1 at 1 V. The presence of CO 2 and CO 3 2– indicates that the EGOR of PdPtBiTe is 10e – C1 oxidation reaction with C–C bond cleavage (Figure b,e) (CH 2 OH–CH 2 OH – 10e – + 14OH – → 2CO 3 2– + 10H 2 O). , During glycerol oxidation, the bands at 1068 and 1111 cm –1 indicate the existence of glycolate and glycerate, and the bands at 1580 and 1420 cm –1 are symmetric and antisymmetric stretching vibration peaks of carboxylate, which may be glycerate or tartaric acid. The bands at 1308 cm –1 for oxalate, 1382 cm –1 for CO 3 2– , and 2345 cm –1 for CO 2 are detected, indicating the cleavage of the C–C bond (Figure c,f) (HOCH 2 –CHOH–CH 2 OH – 14e – + 20OH – → 3CO 3 2– + 14H 2 O). − The cleavage of the C–C bond in alcohol oxidation would be beneficial for the excellent activity of PdPtBiTe/C. − In addition, the in situ FTIR spectra in MOR show the band at 1580 cm –1 and the double peak at 1380 cm –1 are antisymmetric and symmetric stretching vibration peaks of formate, respectively (Figure S12a). , CO 3 2– at 1378 cm –1 is generated in alkaline medium with the increase of the voltage, and CO 2 is detected from 2345 cm –1 at 0.7 V (Figure S12b), which indicates that PdPtBiTe/C realizes full oxidation of 6e – in MOR (CH 3 OH – 6e – + 8OH – → CO 3 2– + 6H 2 O). , …”

Synergistic Effect of Electrocatalyst for Enhanced Oxygen Reduction Reaction: Low Pt-Loaded CuPt Alloy Nanoparticles Supported on N-Doped Hierarchical Porous Carbon

“…Compared to other metals, Cu shows a similar lattice parameter with Pt, enabling the easy formation of well-defined alloyed structures with a predictable electronic configuration . Recent advancements in electrocatalysis have spotlighted PtCu-based catalysts as a promising avenue for enhancing the efficiency of ORR. , These novel catalysts, characterized by their unique alloy structures and optimized surface properties, demonstrate significant improvements in catalytic activity and stability compared to traditional platinum-based catalysts …”