The practical applications of CO 2 electroreduction to CO driven by renewable electricity should simultaneously meet the requests of industrial-level CO partial current density (J CO ) at least 100 mA cm −2 , wide potential window of high CO faradic efficiency (FE CO ), and low cost. Herein, a new strategy is reported to construct porous hierarchical Ni/N/C single-site catalyst with excellent catalytic activity via coating Ni-containing ZIF-8 on mesostructured basic magnesium carbonate template followed by pyrolysis. The abundant micropores facilitate the formation of numerous edge-hosted Ni-N 4 sites with high intrinsic activity, and the interconnected macro/mesopores much promote CO 2 delivery and CO release for the full expression of intrinsic activity. Consequently, the catalyst exhibits the industrial-level J CO of 105-462 mA cm −2 at the potential range of −0.6∼−1.3 V with ultra-wide high FE CO plateau (>90%@−0.4∼−1.3 V), showing great promise for practical application. This study provides a general synthetic strategy to explore high-performance hierarchical M/N/C electrocatalysts.

Electrochemical CO2 reduction reaction (CO2RR) to value‐added chemicals/fuels is an effective strategy to achieve the carbon neutral. Palladium is the only metal to selectively produce formate via CO2RR at near‐zero potentials. To reduce cost and improve activity, the high‐dispersive Pd nanoparticles on hierarchical N‐doped carbon nanocages (Pd/hNCNCs) are constructed by regulating pH in microwave‐assisted ethylene glycol reduction. The optimal catalyst exhibits high formate Faradaic efficiency of >95% within −0.05–0.30 V and delivers an ultrahigh formate partial current density of 10.3 mA cm−2 at the low potential of −0.25 V. The high performance of Pd/hNCNCs is attributed to the small size of uniform Pd nanoparticles, the optimized intermediates adsorption/desorption on modified Pd by N‐doped support, and the promoted mass/charge transfer kinetics arising from the hierarchical structure of hNCNCs. This study sheds light on the rational design of high‐efficient electrocatalysts for advanced energy conversion.