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

Abstract Electrochemical CO 2 reduction reaction (CO 2 RR) to value‐added chemicals/fuels is an effective strategy to achieve the carbon neutral. Palladium is the only metal to selectively produce formate via CO 2 RR 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.