Controlled Synthesis of EDTA Modified Porous Hollow Copper Microspheres for High-efficiency Conversion of CO2 to Multi-Carbon Products.

Electrochemical reduction of CO2 into value-added products is an effective approach to relieve environmental and energetic issues. Herein, self-assemble EDTA anions-modified porous hollow copper microspheres (H-Cu MPs) were constructed by a fully space confined electrodeposition. Needless to post-modification, EDTA anions functioned as functional groups to regulate the surface electron density distribution and stabilize the key intermediate thus altering catalytic path towards ethylene. With the addition of EDTA-2Na, the faradic efficiency (FE) of ethylene doubled from 23.3% to 50.1% at -0.82 V vs RHE in nearly neutral 0.1 M KHCO3 solution, one of the highest values among copper-based electrodeposited catalysts. Besides, theoretical calculations revealed the function of adsorbed EDTA anions. They are able to create a local charged copper surface and stabilize transition state and dimer synergistically on the surface via interaction with OCCO adsorbates, which contributed to the outstanding catalytic performance.