Li–CO₂ batteries (LCOBs) have garnered significant research interest in recent years owing to their exceptional theoretical energy density and potential carbon neutrality responses. However, challenges such as the stable thermodynamic properties of CO₂ and the nonconductivity of product Li₂CO₃ still hinder the practical application of LCOBs, resulting in high overpotential, poor energy conversion efficiency, and restricted capacity. It is believed that changing the electronic structure of the CO₂ cathodic catalyst to improve the inert interface of product nucleation and decomposition by manipulating the d-band center of transition metal-based materials could effectively solve the problem of sluggish kinetics of both CO₂ reduction reaction (CO₂RR) and CO₂ evolution reaction (CO₂ER). In this review, we summarize the ongoing progresses of representative cathodic catalysts for LCOBs from 2015 to 2024. We also evaluate the correlation between catalyst morphology and structure characteristics on the electrochemical activity of LCOBs. More importantly, we systematically discuss the d-band center regulation strategies that alter the electronic properties of catalysts, including heteroatom doping, defect/vacancy engineering, surface/interface engineering, crystalline engineering, heterojunction, atomic-sized catalysis, and strain modulation. We believe that this review would offer a profound understanding on the optimization of electronic configuration for CO₂ cathodic materials in LCOBs.

Reducing the greenhouse gas CO₂ in the atmosphere and converting it into high-value-added syngas is regarded as a competitive strategy in line with green and sustainable development. Herein, a series of M/TiO₂ (M = Cu, Co, Ni) catalysts were developed for photothermal CO₂ reduction with bioethanol, and the synergistic mechanism between photocatalysis and thermocatalysis was deeply investigated. Systematic characteristics and photothermal ethanol dry reforming (EDR) testing results revealed the relevancy between catalytic behavior and microstructure properties of TiO₂-supported catalysts. Notably, the Ni/TiO₂ catalyst displayed superior catalytic behavior than Cu/TiO₂ and Co/TiO₂ counterparts, which mainly attributed to their abundant oxygen vacancies and stronger Ni–TiO₂ interaction. In addition, both the narrower band gap and higher light absorption ability directly promoted the Ni/TiO₂ catalyst possessing outstanding ethanol conversion (94.5%) and controllable H₂/CO ratio (0.65) at 450 ℃. Furthermore, the relatively less activation energy also determined that the Ni/TiO₂ sample possessed the fastest kinetic progression in the EDR process. Therefore, the Ni/TiO₂ catalyst exhibited the better photothermal catalytic activity compared with other 2 samples. We anticipate that photothermal synergy would offer good technical guidance to promote the conversion and utilization of greenhouse gas CO₂ under relatively low temperature environment.