Surface Reconstruction of Ultrathin Palladium Nanosheets during Electrocatalytic CO₂ Reduction

Abstract

A surface reconstructing phenomenon is discovered on a defect-rich ultrathin Pd nanosheet catalyst for aqueous CO 2 electroreduction. The pristine nanosheets with dominant (111) facet sites are transformed into crumpled sheet-like structures prevalent in electrocatalytically active (100) sites. The reconstruction increases the density of active sites and reduces the CO binding strength on Pd surfaces, remarkably promoting the CO 2 reduction to CO. A high CO Faradaic efficiency of 93 % is achieved with a site-specific activity of 6.6 mA cm À2 at a moderate overpotential of 590 mV on the reconstructed 50 nm Pd nanosheets. Experimental and theoretical studies suggest the CO intermediate as a key factor driving the structural transformation during CO 2 reduction. This study highlights the dynamic nature of defective metal nanosheets under reaction conditions and suggests new opportunities in surface engineering of 2D metal nanostructures to tune their electrocatalytic performance.

Tuning the efficiency and product composition for electrocatalytic CO2reduction to syngas over zinc films by morphology and wettability

“…24,25 Even though a majority of catalysts can tune the CO/H 2 yield via modulating the active sites for CO 2 reduction reaction (CO 2 RR) and HER, the catalytic activity is still limited by the low concentration of CO 2 and slow diffusivity to the catalyst surface. 26,27 The unbalanced distribution of CO 2 and H 2 O on the catalyst surface also leads to the lower stability of the catalysts. The design and preparation of efficient catalysts to achieve a desirable balance between CO 2 RR and HER is very interesting.…”

Highly stable Pd/HNb3O8-based flexible humidity sensor for perdurable wireless wearable applications

“…This agrees well with the interplanar distance between the lattice planes of metallic Pd(111). 30 Compared to pristine HNb 3 O 8 nanosheets, the Raman spectrum of Pd/HNb 3 O 8 nanosheets shows a significant weakening of all Raman modes, indicating that the crystallinity markedly decreases inside the microstructure of Pd-modified HNb 3 O 8 nanosheets (Fig. 1h).…”

Seeing is believing: In-situ visualising dynamic evolution in CO2 electrolysis

“…Zhao et al mapped, using high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), the structural transformation of ultrathin Pd nanosheets under CO2RR. [23] As shown 3 in Figure 1b, after a short time of electrolysis (300 s), while the original morphology was maintained, the edges curled slightly and the nanopores shifted to the basal planes. When at 25 min, the basal surfaces became amorphous and rough.…”