Breaking the single-molecule paradigm: Multilayer cobalt phthalocyanine/carbon core-shell structure as the superior active unit for CO2-to-CO electroreduction
Tengyi Liu, Di Zhang, Yue Chu, Keitaro Ohashi, Yutaro Hirai, Koju Ito, Kosuke Ishibashi, Yasutaka Matsuo, Junya Yoshida, Shimpei Ono, Kazuhide Kamiya, Hao Li, Hiroshi Yabu
Abstract
Conventional “chemical intuition” attributes the electrocatalytic activity of phthalocyanines (Pc) to idealized single-molecule/carbon models, however, we reveal that a multilayer Pc/carbon architecture more accurately reflects the true active units. Using AI-powered large-scale data mining (AIP-LDM), we examined 220 metal-nitrogen-carbon (M-N-C) materials for CO 2 -to-CO electroreduction, identifying cobalt-phthalocyanine (CoPc) as a promising candidate. When integrated with Ketjen Black (KB), the resulting CoPc/KB electrode achieves a large CO current density of -595 mA cm -2 and a high mass activity of 6537 A g -1 , while maintaining >90% CO selectivity at -100 mA cm -2 for 100 h. Comprehensive analyses reveal CoPc molecules form polycrystalline layers on KB, creating a multilayer CoPc/carbon core-shell structure that induces surface charge transfer (SCT). Theoretical calculations confirm even minimal SCT significantly enhances intrinsic activity. Further AIP-LDM findings show our hybrid surpasses all reported Pc-based catalysts, highlighting this multilayer Pc/carbon architecture’s advantages and affirming its strong industrial potential in Pc materials.