Nickel phthalocyanine anchored onto N-doped biochar for efficient electrocatalytic carbon dioxide reduction

Molecular catalysts have been receiving extensive attention due to their explicit, designable, easily modifiable molecular structures and tunable catalytic active sites, which exhibit elegant electrocatalytic performance in electrocatalytic carbon dioxide reduction reactions. However, the susceptibility to aggregation due to strong intermolecular π-π interactions among the metal bipyridines, phthalocyanines and porphyrins among the molecular catalysts limits their catalytic performance. Herein, an active catalyst nickel phthalocyanine anchored N-doped ball milled biochar (NiPc/N-BMBC) was developed with highly enriched pore structure and high surface area for electrocatalytic CO2 reduction reaction. On the nanoscale, NiPc molecules were uniformly anchored on N-BMBC to enhance the dispersion, exposing sufficient catalytic active sites. Concretely, the catalyst NiPc/N-BMBC exhibited extraordinary performance in the electrolytic conversion of CO2 reduction reaction, with a Faredaic efficiency of CO (FECO) > 70 % at an overpotential (−0.75 to −0.95 V vs. RHE) and a high CO partial current density (jCO) of 96 mA cm−2 at −1.0 V vs. RHE, which were much higher than that of NiPc (24 %, 38 mA cm−2) and N-BMBC (9 %, 2 mA cm−2). This work provides a new insight in the structural design of carbon-based electrocatalyst for efficient electrocatalytic CO2 reduction reaction.