Ultrastable Implanting-Structured Catalyst for Long-Lasting Acidic CO₂ Electrolysis with Industrial-Level Current Densities

Acidic electrocatalytic CO₂ reduction reaction (CO₂RR) holds promise for high CO₂ utilization. However, corrosive and reductive acidic electrolytes typically cause catalyst degradation and undesirable self-reduction. In this study, we strategically design an implanting-structured catalyst encompassing Bi₂O₃ nanoparticles (NPs) core within zeolite crystals through a novel stepwise seed-directed crystallization technique. This design potently inhibits the dissolution, detachment, agglomeration and reshaping of NPs during acidic CO₂RR and precisely controls NP size to offer high-density active sites per unit area. The concomitant strong metal oxide-support interaction induces the electron shielding effect, which drives electrons unidirectionally exported from Bi to *OCHO intermediate and zeolite but prevents the electron inflow to Bi, preventing the working Bi₂O₃ from self-reduction during acidic CO₂RR. Meanwhile, the interfacial electron transfer steers the CO₂RR intermediates coverage by enhancing *OCHO intermediate stabilization and weakening *H binding. This innovative catalyst has been effectively utilized in acidic CO₂ electrolysis, attaining a maximum HCOOH Faradaic efficiency (FE) of 99% and a remarkable partial current density of 865 mA cm⁻² at 1 A cm⁻², particularly achieving extraordinary stability – sustain FE exceeding 94% for 500 hours in strongly acidic media. This work opens up new opportunities of ultrastable implanting-structured catalyst for long-lasting acidic CO₂ electrolysis and other catalytic systems.