Charge-Separated Pd?--Cu? plus Atom Pairs Promote CO2 Reduction to C2

Positively charged Cu sites have been confirmed to significantly promote the production of multicarbon (C2) products from an electrochemical CO2 reduction reaction (CO2RR). However, the positively charged Cu has difficulty in existing under a strong negative bias. In this work, we design a Pd delta--Cu3N catalyst containing charge-separated Pd delta--Cu delta+ atom pair that can stabilize the Cu delta+ sites. In situ characterizations and density functional theory reveal that the first reported negatively charged Pd delta- sites exhibited a superior CO binding capacity together with the adjacent Cu delta+ sites, synergistically promoting the CO dimerization process to produce C2 products. As a result, we achieve a 14-fold increase in the C2 product Faradaic efficiency (FE) on Pd delta--Cu3N, from 5.6% to 78.2%. This work provides a new strategy for synthesizing negative valence atom-pair catalysts and an atomic-level modulation approach of unstable Cu delta+ sites in the CO2RR.

Automated summary

In this work, a Pd delta--Cu3N catalyst containing charge-separated Pd delta--Cu delta+ atom pair is designed to stabilize the Cu delta+ sites and promote the CO dimerization process. The achieved 14-fold increase in C2 product Faradaic efficiency demonstrates the effectiveness of this strategy for enhancing CO2 RR.