Alleviating Ni electron depletion of Ni phthalocyanine by doping electron-deficient boron in CNTs support for enhanced CO2 electroreduction.

[Display omitted] • Ni electron depletion on NiPc/CNTs is alleviated by doping electron-deficient B. • Ni site in NiPc/B-CNTs is electron-enriched state, lowering CO 2 RR reaction barrier. • The NiPc/B-CNTs presents prominent CO 2 RR performance in neutral electrolytes. Dispersed nickel phthalocyanine (NiPc) on carbon nanotubes (CNTs) is the promising electrocatalyst for carbon dioxide reduction (CO 2 RR), but the strong interfacial electron interaction causes Ni electron depletion, limiting CO 2 RR performance. Herein, engineering the heteroatom doping in CNTs is proposed to alleviate electron depletion of Ni sites toward effective CO 2 RR. Boron heteroatoms induce electron-enriched Ni sites in NiPc/B-CNTs compared to phosphorus, nitrogen, and fluorine doped catalysts, resulting in superior CO 2 RR performance. Impressively, the NiPc/B-CNTs presents high CO Faraday efficiency (FE CO) of >98 % from −20 to −80 mA cm−2 and excellent stability up to 37 h with sustained FE CO of > 90 % in neutral electrolyte. Theoretical and experimental investigation reveals that implanting B heteroatoms alleviates Ni electron depletion via weakening electron transfer from NiPc to CNTs and thus reduces reaction barrier of *COOH formation, facilitating CO 2 RR. This study highlights importance of modifying carbon substrate in development of supported molecular catalysts for practical applications. [ABSTRACT FROM AUTHOR]