Enhancing the selective electrochemical conversion of nitrate via π back-donation on Lewis acid sites induced by noble-metal doped CoP

Abstract

Nitrate is a typical Lewis base, while noble-metals have unoccupied d-orbitals that can form Lewis acidic sites. Therefore, Pd/CoP can utilize Lewis acid–base interactions to promote the adsorption and conversion of NO3−.

Hydrogen Spillover Boosted Hydrogen Evolution Electrocatalysis over Pd@CoP in Alkaline Seawater

“…34,35 Notably, the Pd@CoP peaks shift to higher binding energies relative to CoP, which is likely due to electron transfer between Pd and Co atoms. 36 Furthermore, the P 2p spectrum of Pd@CoP (Figure 2d) exhibits peaks at 130.5 and 129.6 eV, assigned to P 2p 1/2 and P 2p 3/2 , respectively. The peak at 133.2 eV corresponds to P−O, resulting from superficial oxidation of the metal phosphide after exposure to air.…”

“…37−39 After decorating with Pd, compared to CoP, the P 2p 3/2 and P 2p 1/2 peak areas of Pd@CoP significantly increased and the P 2p peak exhibited a slight negative shift, indicating enhanced electronic interactions and reduced electron density around Pd atoms, thereby improving the material's conductivity. 36 The electrocatalytic performance of these samples (Pd@ CoP/NF, CoP/NF, and Pt/C/NF) toward the HER was systematically studied using a standard three-electrode setup in alkaline seawater. The HER linear sweep voltammetry (LSV) curves are illustrated in Figure 3a to visually compare the catalytic activity of these samples.…”

“…Additionally, satellite (Sat.) peaks at 786.3 and 803.5 eV indicate the oxidation state of Co resulting from surface oxidation in air. , Notably, the Pd@CoP peaks shift to higher binding energies relative to CoP, which is likely due to electron transfer between Pd and Co atoms . Furthermore, the P 2p spectrum of Pd@CoP (Figure d) exhibits peaks at 130.5 and 129.6 eV, assigned to P 2p 1/2 and P 2p 3/2 , respectively.…”

“…Furthermore, the P 2p spectrum of Pd@CoP (Figure d) exhibits peaks at 130.5 and 129.6 eV, assigned to P 2p 1/2 and P 2p 3/2 , respectively. The peak at 133.2 eV corresponds to P–O, resulting from superficial oxidation of the metal phosphide after exposure to air. − After decorating with Pd, compared to CoP, the P 2p 3/2 and P 2p 1/2 peak areas of Pd@CoP significantly increased and the P 2p peak exhibited a slight negative shift, indicating enhanced electronic interactions and reduced electron density around Pd atoms, thereby improving the material’s conductivity …”