The electrochemical conversion of CO₂ to fuels and feedstock may be an elegant solution to realize carbon neutral, remit the environmental, and alleviate energy crisis. Among various products, CH₄, as an important fuel and a simple C1 product of CO₂, still can’t be achieved with high selectivity due to the eight electrons pathway from CO₂ to CH₄. 

In a study published in Angew. Chem. Int. Ed., Prof. CAO Rong, Prof. HUANG Yuanbiao and Prof. CHAI Guoliang from Fujian Institute of Research on the Structure of Matter (FJIRSM) of the Chinese Academy of Sciences (CAS) proposed a facile way to obtain Cu₂O single-type sites in situ generated on a Cu-based conductive metal organic framework (MOF), exhibiting high selectivity of 73% towards CH₄. 

The researchers synthesized the conductive Cu-MOF, CuHHTP by a facile solvothermal method using copper acetate and the conjugated tricatecholate ligand. The strong charge delocalization between Cu²⁺ and ligands endows CuHHTP with superior electronic conductivity. After a facile electroreduction process, partial of labile Cu-O₄ nodes in CuHHTP were transformed in situ into Cu₂O(111) single-type sites. 

As a result, the obtained catalyst exhibited outstanding CO₂ electroreduction performance with 73% Faradaic efficiency of the conversion from CO₂ to CH₄, outperforming most electrocatalysts, especially MOF-based catalysts. 

From both experimental and theoretical point of view, the operando infrared spectroscopy study and density functional theory (DFT) calculations revealed that the key intermediates, such as *CH₂O and *OCH₃, involved in the pathway of CH₄ formation are stabilized by the single active Cu₂O(111) and hydrogen bonding, thus generating CH₄ instead of CO. 

This study provides an effective strategy to modulate the selectivity of CO₂ electroreduction by designing single types of active sites and stabilizing key intermediates with hydrogen bond and improve the current density using conductive framework materials.