Saturated Coordination LuN₆ Defect Sites for Highly Efficient Electroreduction of CO₂

Abstract

Metal single‐atom and internal structural defects typically coexist in M–N–C materials obtained through the existing basic pyrolysis processes. Identifying a correlation between them to understand the structure–activity relationship and achieve efficient catalytic performance is important, particularly for the rare‐earth (RE) elements with rich electron orbitals and strong coordination capabilities. Herein, a novel single‐atom catalyst based on the RE element lutetium is successfully synthesized on a N–C support. Structural and simulation analyses demonstrate that the formation of a LuN6 structural site with an individual defect because of pyrolysis is thermodynamically favorable in Lu–N–C. Using KHCO3‐based electrolytes facilitates the fall of the K+ cations into the defective sites of Lu–N–C, thus enabling improved CO2 capture and activation, which increases the catalyst conductivity for Lu–N–C. In this study, the catalyst exhibits a Faradaic efficiency of 95.1% for CO at a current density of 18.2 mA cm−2 during carbon dioxide reduction reaction. This study thus provides new insights into understanding RE–N–C materials for energy utilization.

Rare-earth metal-N6 centers in porous carbon for electrocatalytic CO2 reduction

“…33 This concept was reinforced by the analysis of single atom catalysts containing the rare earth elements Pr 34 and Lu. 48 Therefore, it is likely that the single-atom Eu–N–C catalysts we synthesised have an Eu-N 6 C coordination structure. According to the partial calculation in Section 3.4, the reaction path for the electrocatalytic CO 2 reduction by Eu-N 6 C is * + CO 2 → *COOH → *CO → * + CO.…”

Evaluating the Oxygen Electrode Reactions of La Single-Atom Catalysts with the N/C Coordination Effect

“…The active atoms with large sizes tend to anchor on carbon vacancies through the six coordination bonds. , Therefore, as shown in Figure , the 5 × 5 graphene supercell was adopted to simulate the carbon substrate, create four carbon vacancies in the center to anchor the La atom, and adjust the C/N coordination to tune the electronic properties of the active atom. The vacuum layer was set to 30 Å to avoid false interlayer interference.…”

Customization from Single to Dual Atomic Sites for Efficient Electrocatalytic CO2 Reduction to Value‐added Chemicals

“…The utilization of renewable electricity can effectively convert excess CO 2 , into valuable fuels and chemicals, which helps to establish a low‐carbon emission economy and achieve carbon neutrality goals. Despite the progress made in electrochemical CO 2 RR in the past few years, it still faces non‐negligible problems, including slow CO 2 activation, competitive hydrogen precipitation reaction (HER), low product selectivity and unsatisfactory electrolytic durability [4–5] . And the key to solve these problems lies in the development of highly active, selective and stable electrocatalysts.…”