Pd–Ag Alloy Electrocatalysts for CO₂ Reduction: Composition Tuning to Break the Scaling Relationship

Abstract

Constructing solid-solution-alloy electrocatalysts with tunable surface electronic configurations is the key to optimize intermediate bindings and thereby to promote the activity and selectivity of the CO2 reduction reaction (CO2RR). Herein, Pd1–x Ag x alloy electrocatalysts are investigated as a platform to uncover the electronic effects on the CO2RR. The optimal Pd0.75Ag0.25/C affords a superior CO Faradaic efficiency of 95.3% at −0.6 V (vs RHE) in 0.5 M KHCO3, performing at a high level among recently reported electrocatalysts. Experimental and theoretical analysis further evidence that varying the composition of Pd1–x Ag x alloys can effectively alter the electronic configurations and consequently break the inherent scaling relationship of the binding energy of different intermediates (*COOH and *CO). Among Pd1–x Ag x , Pd0.75Ag0.25 gains the obviously weakened *CO and *H bindings but retained well the binding with *COOH, contributing to the facilitated kinetics toward CO product. Elucidating a feasible way to break the scaling relationship and further uncover the underlying mechanism, this work will inspire new design strategies toward active and selective electrocatalysts.

H2 Activation with Co Nanoparticles Encapsulated in N‐Doped Carbon Nanotubes for Green Synthesis of Benzimidazoles

“…These results can be further interpreted in view of orbital overlapping. Figure 7 thus depicts the DOS of H 1s and N 2p in Cat⋅⋅(2H) state, the overlap between H 1s and N 2p increases in Co 4 @N‐CNT⋅⋅(2H) if compared with N‐CNT⋅⋅(2H), indicating a stronger N−H bond within Co 4 @N‐CNT⋅⋅(2H) (Figure 6, IM2) than in the case of N‐CNT⋅⋅(2H) (Figure 6, IM2) [70–72] . In addition, the increased DOS near Fermi level for Co 4 @N‐CNT⋅⋅(2H) is beneficial to its subsequent hydrogenation reaction (Figure 7).…”

“…(Figure 6, IM2). [70][71][72] In addition, the increased DOS near Fermi level for Co 4 @N-CNT••(2H) is beneficial to its subsequent hydrogenation reaction (Figure 7). [37] After H 2 dissociation on the catalyst, adsorption of 1 a on the Cat••(2H) adduct is a prerequisite for subsequent hydrogenation of the nitro group.…”

The Effect of the Coordination Environment of Atomically Dispersed Fe and N Co‐doped Carbon Nanosheets on CO2 Electroreduction

“…[8][9][10] The utilization of noble-metal catalysts for electroreduction of CO 2 to CO has made excellent progress, such as Au, Ag. [11][12][13] It is well known that the scarcity and cost of precious metals limit their industrial applications. To date, Cu-based catalysts have most abundant product (e. g., HCOOH, CH 3 CH 2 OH, C 2 H 6 , C 2 H 4 ) in the prior reports.…”

“…In recent years, a large number of efforts have been used in the studies of electrocatalysts with excellent properties [8–10] . The utilization of noble‐metal catalysts for electroreduction of CO 2 to CO has made excellent progress, such as Au, Ag [11–13] . It is well known that the scarcity and cost of precious metals limit their industrial applications.…”

>i<Ab Initio>/i< investigation of the adsorption of molecules, involved in carbon dioxide and glycerol utilization, on transition-metal substrates

“…208 Besides the type of TM, the proportion of each component of the nanoalloy is critical to design better catalysts; for example, the composition of PdAg alloys can be tuned to weaken the binding of CO with respect to other intermediates during the electroreduction of CO 2 . 209 Similarly, it was possible to change the selectivity of CuSn catalysts through composition by increasing the quantities of positively charged Sn sites. 210 Unfortunately, despite the fact that various alloys can be suggested to greatly improve the electroreduction of CO 2 , the materials can be unstable and prone to segregation or degradation.…”