Atomically Structural Regulations of Carbon‐Based Single‐Atom Catalysts for Electrochemical CO₂Reduction

Abstract

Fossil fuels as the traditional energy sources have been extensively used to improve the living standards for human beings since the industrial revolution in 19th century. [1] However, the burning of coal, petroleum, and natural gas has given rise to the uncontrolled growth of notorious greenhouse gas CO 2 concentration, resulting in a series of climate changes, such as average

Mechanistic understanding and design of non-noble metal-based single-atom catalysts supported on two-dimensional materials for CO2 electroreduction

“…Furthermore, the half-cell reactions in the CO 2 RR with their reduction potentials of the main products at pH 7 are listed in Table 2. 41 Most commonly, the CO 2 RR on SACs proceeds through a two-electron transfer process and generates CO or formate, balanced with oxygen evolution reaction (OER) as the anodic reaction. 10 However, the selectivity of the CO 2 RR over carbon-based SACs requires specific attention because several factors are believed to influence the catalytic performance and reduced products.…”

“…From a thermodynamic perspective, the reduction potential from CO 2 to CO is slightly different from the HER ( E 0 (CO 2 /CO) = −0.11 V vs. RHE). 41 However, the high kinetic barrier of CO 2 activation leads to a sluggish reaction rate, which requires careful selection of metal centers and improved catalyst designs. 42 Due to the reduction process mainly occurring at metal sites, the type of the metal center directly leads to distinct electronic properties and further affects the reaction pathways.…”

Low‐dimensional material supported single‐atom catalysts for electrochemical CO2 reduction

“…Specific to ECR, the first example of ECR over SACs was reported by Meshitsuka et al 42 They studied the polarization curves of the metal phthalocyanines (CoPc and NiPc) attached to graphite electrodes in a CO 2 ‐saturated aqueous solution. After that, the reports of SACs for ECR increase gradually 43–48 . The similar spatial configurations and electronic structures of the well‐defined active centers in SACs make them potentially avoid the unwanted reaction paths or weaken the competitive HER during the ECR process.…”

“…After that, the reports of SACs for ECR increase gradually. [43][44][45][46][47][48] The similar spatial configurations and electronic structures of the well-defined active centers in SACs make them potentially avoid the unwanted reaction paths or weaken the competitive HER during the ECR process. For example, Jung et al 46 has compared the free energy change of the initial protonation steps of ECR and HER over graphene-supported SACs through DFT calculations.…”

“…However, when the size of Ni is reduced to a single-atom scale and dispersed on the carbon support, they become highly selective for CO 2 electroreduction to CO. 50 In addition, the CO 2 reduction activity and selectively can be tailored by engineering the microenvironment in SACs. 45,51,52 These features make SACs show great prospects for highly efficient ECR.…”