Controlling nitric oxide reduction to ammonia on defective α-In2Se3via ferroelectric polarization switching

Abstract

The electrochemical nitric oxide reduction reaction (NORR) offers a sustainable route to simultaneously remove atmospheric NO and produce valuable NH₃. However, designing catalysts that are both highly active and selective under ambient conditions remains challenging. Using density functional theory (DFT), we investigate—for the first time—how switching the polarization direction of a two-dimensional (2D) ferroelectric α-In₂Se₃ monolayer with Se vacancies (V_Se) influences its stability, activity, and selectivity for the NORR. Polarization reorientation redistributes electrons between the catalyst surface and adsorbed NO, effectively tuning the adsorption strength, reaction pathway, limiting potential, and final products. Specifically, the V_Se–In₂Se₃↓ configuration demonstrates superior catalytic activity with a much lower limiting potential than its V_Se–In₂Se₃↑ counterpart, while also suppressing byproduct formation and hydrogen evolution reaction (HER). Our work highlights the transformative potential of polarization control in 2D ferroelectric materials for designing efficient electrocatalysts.