Sequential deposition of FeNC-Cu tandem CO₂ reduction electrocatalysts towards the low overpotential production of C₂₊ alcohols

Tandem CO₂ reduction electrocatalysts that combine a material that selectively produces CO with Cu are capable of producing hydrocarbons at low overpotentials and high selectivity. However, controlling the spatial distribution and the catalytic activity of the CO-making catalyst remains a challenge. In this work, a novel tandem electrocatalyst that overcomes limitations of simple Cu catalysts, namely selectivity and efficiency at low overpotential, is presented. The tandem electrocatalysts are prepared through a sequential spray coating protocol, using a single atom Fe in N-doped C (FeNC) as the selective CO-producing catalyst and commercial Cu nanopowder. The high faradaic efficiency towards CO of FeNC (99% observed at −0.60 V vs. RHE) provides a high CO coverage to the Cu particles, leading to reduced hydrogen evolution and the selective formation of ethanol and n-propanol at a much low overpotential than that of bare Cu.