High‐Dispersive Pd Nanoparticles on Hierarchical N‐Doped Carbon Nanocages to Boost Electrochemical CO2 Reduction to Formate at Low Potential

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.