Confining lead-free perovskite in extra-large pore zeolite for selective electrocatalytic NO3− to NH3

Metal halide perovskite quantum dots have garnered significant attention in photovoltaics and photocatalysis due to their tunable band gap, high charge carrier mobility, and long charge diffusion length. In this study, we introduced lead-free perovskite quantum dots (Cs 2 AgBiI 6 ) into cages of stable extra-large-pore zeolites (ZEO-1) as novel electrocatalysts for ammonia synthesis. The ultrahigh specific surface area and interconnected 3D pore network of ZEO-1 not only suppressed Cs 2 AgBiI 6 aggregation but also enhanced interfacial stability via Si–OH··I − hydrogen bonding. The host-guest composites of Cs 2 AgBiI 6 @ZEO-1 exhibited superior catalytic activity, with an NH 3 Faradaic efficiency of 93% and a yield rate of 691 μmol h −1 mg −1 (691 μmol h −1 cm −2 ) at −1.7 V vs. Ag/AgCl. The superior electrocatalytic performance of Cs 2 AgBiI 6 @ZEO-1 was attributed to the confinement effect of the 3D extra-large pores of ZEO-1, which provided more exposed active sites for nitrate reduction reaction (NO 3 RR). In addition, Cs 2 AgBiI 6 /BiOI dynamically reconstructed by Cs 2 AgBiI 6 acts as a true catalytic center in the catalytic reaction, which can effectively reduce the reaction energy barrier of the rate-determining step, thereby accelerating the reaction process. This work establishes a scalable nanoconfinement strategy for integrating quantum dots within porous hosts, offering a versatile platform for energy-efficient NO 3 − reduction and sustainable ammonia synthesis.