Engineering a Pyridinic N–Ni Single-Atom Catalyst for Efficient Low-Temperature CO ₂ Methanation

Low-temperature methanation enables near-equilibrium conversion of CO 2 to methane, offering significant energy efficiency and economic benefits. However, designing catalysts that can activate CO 2 at low temperatures without relying on noble metals remains a fundamental challenge in CO 2 valorization. Here, we present a pyridinic N–Ni single atom (Ni–N 3 ), where atomically dispersed Ni atoms were anchored by three pyridinic nitrogen atoms. The precise nitrogen coordinated environment enabled 100% CH 4 selectivity and 78.9% CO 2 conversion at 250 °C. A record CH 4 space-time yield of 1972 mmol CH 4 g cat. –1 h –1 was attained with a gas hourly space velocity of 320,000 mL g cat. –1 h –1 at 400 °C, surpassing literature benchmarks. According to the mechanistic study, Ni–N 3 facilitated a formate-driven reaction mechanism, which improved the CH 4 selectivity via entirely bypassing the CO intermediates and enhanced the CO 2 conversion by reducing the activation energy. These findings establish a new strategy for rational catalyst design in which local coordination geometry governs the fundamental mechanism of CO 2 hydrogenation.