Tailoring the local acid-like microenvironment with the synergism of nanoscale and atomically local electric fields for enhanced hydrogen spillover in alkaline seawater electrolysis

Abstract

Creating an environment with a high concentration of acidic protons in the absence of a Lewis acid layer is challenging for alkaline seawater hydrogen spillover (HSo). Herein, we introduce a synergistic strategy by creating both nanoscale and atomically local electric fields to generate a local high-concentration acid-like environment. This is demonstrated by incorporating multiple atomically dispersed Ru nanoparticles (Ru NPs) on the surface of Co_xPv@C. Finite element method (FEM) simulations and advanced characterizations illustrate that the nanoscale and atomically local electric fields promote the formation of a significant number of H₃O⁺, creating a local acid-like environment around the surface of multiple Ru NPs. The small work function difference (ΔΦ) of 0.05 eV between Ru and Co_xP@C is found to be favorable for interfacial HSo. In situ Raman spectroscopy confirms that the formed P–H bond acts as a proton “sponge”, storing H⁺ and quickly transferring them to the Ru NPs surface, where they combine with adjacent H₂O molecules to form H₃O⁺, thus promoting HSo. Additionally, the carbon layer and the inherent corrosion resistance of Co_xPv@C can effectively protect the Ru NPs from the toxicity and corrosion caused by Cl⁻. Consequently, the Ru-Co_xPv@C catalyst exhibits long-term stability for 200 h at 10 mA cm² in alkaline seawater electrolyte.