Electronic Structure Design of Transition Metal-Based Catalysts for Electrochemical Carbon Dioxide Reduction

Abstract

With the increasingly serious greenhouse effect, the electrochemical carbon dioxide reduction reaction (CO 2 RR) has garnered widespread attention as it is capable of leveraging renewable energy to convert CO 2 into value-added chemicals and fuels. However, the performance of CO 2 RR can hardly meet expectations because of the diverse intermediates and complicated reaction processes, necessitating the exploitation of highly efficient catalysts. In recent years, with advanced characterization technologies and theoretical simulations, the exploration of catalytic mechanisms has gradually deepened into the electronic structure of catalysts and their interactions with intermediates, which serve as a bridge to facilitate the deeper comprehension of structure−performance relationships. Transition metal-based catalysts (TMCs), extensively applied in electrochemical CO 2 RR, demonstrate substantial potential for further electronic structure modulation, given their abundance of d electrons. Herein, we discuss the representative feasible strategies to modulate the electronic structure of catalysts, including doping, vacancy, alloying, heterostructure, strain, and phase engineering. These approaches profoundly alter the inherent properties of TMCs and their interaction with intermediates, thereby greatly affecting the reaction rate and pathway of CO 2 RR. It is believed that the rational electronic structure design and modulation can fundamentally provide viable directions and strategies for the development of advanced catalysts toward efficient electrochemical conversion of CO 2 and many other small molecules.

Manipulating the Coordination Structure of Molecular Cobalt Sites in Periodic Mesoporous Organosilica for CO2 Photoreduction

“…Three different organic dyes (9-cyanoantharecene, purpurin or 4CzIPN) were subsequently screened for photocatalytic activity, but CO evolution was observed only in the presence of 4CzIPN. Under this condition, CoN5-PMO outperformed the other catalysts with a CO evolution of 2.54 µmol mg -1 , CO selectivity of 71%, and a TOFCO of 62 h -1 (Table 1, entry [9][10][11][12]. This result confirms that the Co centres coordinated to five N atoms provide the optimum active site structure for effective CO2 photoreduction.…”

“…From a catalyst design perspective, a wide range of molecular catalysts based on transition metal complexes have been developed for application in CO2 photoreduction by coupling with molecular sensitisers or light harvesting semiconductors. [8][9][10][11] While molecular catalysts offer distinct benefits such as better atom efficiency, high product selectivity, tuneability and scope for mechanistic understanding, they often suffer from poor stability and are non-recyclable when used under homogeneous condition.…”

Manipulating the Coordination Structure of Molecular Cobalt Sites in Periodic Mesoporous Organosilica for CO2 Photoreduction

“…From a catalyst design perspective, a wide range of molecular catalysts based on transition metal complexes have been developed for application in CO 2 photoreduction by coupling with molecular sensitizers or light harvesting semiconductors. − While molecular catalysts offer distinct benefits such as better atom efficiency, high product selectivity, tunability, and scope for mechanistic understanding, they often suffer from poor stability and are nonrecyclable when used under homogeneous conditions. However, these shortcomings can be mitigated via heterogenization of the molecular complexes on solid supports, − which bridges between homogeneous and heterogeneous systems and provides an opportunity to precisely regulate the structure of the active site on solid support at atomic levels.…”

Deciphering the role of aromatic cations in electrochemical CO2 reduction: interfacial ion assembly governs reaction pathways

“…One major and conventional category of strategies is engineering electrode surface structures and electronic properties. 3,8–12 For example, increasing the number of low-coordinating sites and grain boundaries on electrode surfaces, 10,13 alloying of metal electrodes, 11,12 and developing new heterogeneous catalytic materials with tunable active sites 14–16 are all demonstrated to increase the rate and selectivity of CO 2 reduction in aqueous solutions by tuning the adsorption energy of key intermediates.…”