Electrocatalytic CO2 reduction to ethylene over CuOx boosting CO2 adsorption by lanthanide neodymium

CO2 electrocatalytic reduction (CO2ER) is an excellent way for synthesizing value-added products and achieving carbon neutrality. While C2+ products, such as C2H4, C2H5OH, etc., have higher energy densities and are more valuable than C1 products, their synthesis is more challenging. In the present work, a series of easily prepared lanthanide neodymium-doped CuOx catalysts (denoted as CuaNdOx, a = 0.2, 0.5, 1, 2, and 5) were developed and applied in CO2ER to produce C2H4. In an H-type cell, the Cu2NdOx catalyst with a Co/Nd molar ratio of 2/1 demonstrated the best catalytic performance with a high FEC2H4 of 54.4% and a current density of 28.4 mA cm-2 at -1.19 V (vs. RHE) in 0.5 M KCl electrolyte. Characterization results showed that the introduction of neodymium could effectively stabilize the Cu(I) species and enhance CO2 adsorption on the catalyst. In situ Raman spectra and DFT calculation confirmed that the Nd sites favor the adsorption and activation of CO2, while the Cu sites are responsible for reducing CO2 to *COOH and *CO. The formed *CO was then coupled to ethylene, further improving the Faradaic efficiency of ethylene (FEC2H4). It is noteworthy that this is the first instance of using lanthanide neodymium as a promoter in Cu-based material catalyzed CO2ER. The present work not only provides efficient Cu-Nd bimetallic catalysts for CO2ER to ethylene but also opens up a new avenue of utilizing Nd-based lanthanide metals in catalysis.

Automated summary

In this study, a series of easily prepared CuOx catalysts were developed and applied in CO2 electrocatalytic reduction to synthesize ethylene; the introduction of neodymium stabilizes the catalyst and enhances CO2 adsorption; coupling *CO with ethylene further improves the Faradaic efficiency of ethylene.