Janus NiN4 -CuN4 Catalyst Supported by Double-layered ZIF-8 Structure for CO2 Electrocatalytic Reduction to C2+ Products

Abstract

Copper (Cu)-based catalysts exhibit considerable potential for electrocatalytic CO₂ reduction reaction (CO₂RR) to multicarbon (C₂₊) products, nevertheless, competitive products (e.g. formic acid) have also been produced by thermodynamic constraints. The attainment of selective C₂₊ products exhibiting high Faradaic efficiency (FE) and current density remains a significant challenge. Here, we designed a tandem catalytic strategy and prepared a series of Janus catalyst supported by double-layered ZIF-8 with inner MN4 and outer CuN₄ for C₂₊ products (especially n-propanol). The synthetic catalyst, NiN₄@CuN₄, achieved high faradaic efficiencies of 80.6% for C₂₊ at -1.6V in flow cell, in which 24.4% for n-propanol (CH₃CH₂CH₂OH) and 36.6% for ethanol (CH₃CH₂OH). In situ Raman experiments along with mechanism analysis indicate that synergistic interaction of inner NiN₄ and outer CuN₄ significantly facilitates CO production and CO electroreduction, thereby greatly promoting C₂₊ production.