Multilayer‐Cavity Tandem Catalyst for Profiling Sequentially Coupling of Intermediate CO in Electrocatalytic Reduction Reaction of CO₂ to Multi‐Carbon Products

Abstract Electrochemical CO₂ reduction reaction (CO₂RR) is an effective approach to address CO₂ emission, promote recycling, and synthesize high‐value multi‐carbon (C₂₊) chemicals for storing renewable electricity in the long‐term. The construction of multilayer‐bound nanoreactors to achieve management of intermediate CO is a promising strategy for tandem to C₂₊ products. In this study, a series of Ag@Cu₂O nanoreactors consisting of an Ag‐yolk and a multilayer confined Cu shell is designed to profile electrocatalytic CO₂RR reactions. The optimized Ag@Cu₂O‐2 nanoreactor exhibits a 74% Faradaic efficiency during the C₂₊ pathway and remains stable for over 10 h at a bias current density of 100 mA cm⁻². Using the finite element method, this model determines that the certain volume of cavity in the Ag@Cu₂O nanoreactors facilitates on‐site CO retention and that multilayers of Cu species favor CO capture. Density functional theory calculations illustrate that the biased generation of ethanol products may arise from the (100)/(111) interface of the Cu layer. In‐depth explorations in multilayer‐bound nanoreactors provide structural and interfacial guidance for sequential coupling of CO₂RR intermediates for efficient C₂₊ generation.