Strain Relaxation in Metal Alloy Catalysts Steers the Product Selectivity of Electrocatalytic CO₂ Reduction

Abstract

Strain engineering in bimetallic alloy structures is of great interest in electrochemical CO2 reduction reactions (CO2RR), in which it simultaneously improves electrocatalytic activity and product selectivity by optimizing the binding properties of intermediates. However, a reliable synthetic strategy and systematic understanding of the strain effects in the CO2RR are still lacking. Herein, we report a strain relaxation strategy used to determine lattice strains in bimetal MNi alloys (M = Pd, Ag, and Au) and realize an outstanding CO2-to-CO Faradaic efficiency of 96.6% and show the outstanding activity and durability toward a Zn-CO2 battery. Molecular dynamics (MD) simulations predict that the relaxation of strained PdNi alloys (s-PdNi) is correlated with increases in synthesis temperature, and the high temperature activation energy drives complete atomic mixing of multiple metal atoms to allow for regulation of lattice strains. Density functional theory (DFT) calculations reveal that strain relaxation effectively improves CO2RR activity and selectivity by optimizing the formation energies of *COOH and *CO intermediates on s-PdNi alloy surfaces, as also verified by in situ spectroscopic investigations. This approach provides a promising approach for catalyst design, enabling independent optimization of formation energies of reaction intermediates to improve catalytic activity and selectivity simultaneously.

Facile synthesis of a novel 0D/2D CdS/Bi4TaO8Br heterojunction for enhanced photocatalytic tetracycline hydrochloride degradation under visible light

“…6b), the CdS/Bi 4 TaO 8 Br-200 sample expressed the smallest semicircle, while the semicircle of the CdS/Bi 4 TaO 8 Br-mechanical sample is the biggest. 44 The consistent photocurrent and EIS results also show that the 0D/2D heterojunction structure can reduce the interface resistance, which is conducive to the transfer and separation of photogenerated carriers. In Fig.…”

An electrochemical modification strategy to fabricate NiFeCuPt polymetallic carbon matrices on nickel foam as stable electrocatalysts for water splitting

“… 6 In particular, the OER remains a bottleneck for EWS owing to its sluggish kinetics. 7 Although attempts have been made to use earth abundant transition metals 8 and their corresponding compounds 9 as electrocatalysts to reduce cost, 10 their poor stability, excessive load and high overpotential partially meet the requirements of practical applications. 11 On the other hand, noble metals such as platinum (Pt), 12 iridium (Ir), 13 ruthenium (Ru) 14 and their corresponding oxides 15 are used as benchmark electrocatalysts towards EWS, given their high efficiency and stability.…”

Co-doped MoS2nanosheet: a stable and pH-universal electrocatalyst for an efficient hydrogen evolution reaction

“…Furthermore, most reported catalysts only demonstrate high hydrogen evolution capability in alkaline solution, which severely restricts their application in actual industrial production. 10,11 Therefore, it is critical to develop efficient and low-cost catalysts for hydrogen evolution over a wide pH range.…”