Toward Unifying the Mechanistic Concepts in Electrochemical CO₂ Reduction from an Integrated Material Design and Catalytic Perspective

Abstract

Electrocatalytic CO2 reduction (eCO2RR) is one of the avenues with most potential toward achieving sustainable energy economy and global climate change targets by harvesting renewable energy into value‐added fuels and chemicals. From an industrial standpoint, eCO2RR provides specific advantages over thermochemical and photochemical pathways in terms of much broader product scope, high product specificity, and easy adaptability to the renewable electricity infrastructure. However, unlike water electrolyzers, the lack of suitable cathode materials for eCO2RR impedes its commercialization due to material design challenges. The current state‐of‐the‐art catalysts in eCO2RR suffer largely from low reaction rates, insufficient C2+ product selectivity, high overpotentials, and industrial‐scale stability. Overcoming the scientific and applied technical hurdles for commercial realization demands a holistic integration of catalytic designs, deep mechanistic understanding, and efficient process engineering. Special emphasis on mechanistic understanding and performance outcome is sought to guide the future design of eCO2RR catalysts that can play a significant role in closing the anthropogenic carbon loop. This article provides an integrative approach to understand principles of robust eCO2RR catalyst design superimposed with underlying mechanistic projections which strongly depend on experimental conditions viz. choice of electrolyte, reactor and membrane design, pH of the solvent, and partial pressure of the CO2.

Electricity-Driven Microbial Metabolism of Carbon and Nitrogen: A Waste-to-Resource Solution

“…An electrochemical setup was constructed under a confocal microscope for in situ characterization of an O 2 gradient, when using O 2 -sensitive microbes for the production of biofertilizer (Figure h) . Different operando techniques for mechanistic investigations of CO2RR have been systematically reviewed recently . For example, in situ differential electrochemical mass spectrometry (DEMS), commonly used to detect molecular intermediates (Figure i), can be further adopted to clarify extracellular intermediates of electricity-driven microbial metabolism.…”

“…136 Different operando techniques for mechanistic investigations of CO2RR have been systematically reviewed recently. 163 For example, in situ differential electrochemical mass spectrometry (DEMS), commonly used to detect molecular intermediates (Figure 7i), 164 can be further adopted to clarify extracellular intermediates of electricity-driven microbial metabolism.…”

Plasmonic Au–Cu nanostructures: Synthesis and applications

“…For example, alloying Au with Cu not only stabilizes Cu but also reduces the overpotential required for CO 2 reduction. In addition to the excess potential, the selectivity of the catalysts during CO 2 reduction must be considered since multiple couplings between protons and electrons lead to many possible reaction products ( Bagchi et al, 2022 ). Yang’s group showed that Au–Cu alloy nanospheres are a highly potential catalyst for CO 2 reduction ( Kim et al, 2014 ).…”

Rational Design of Heterogeneous Dual-Atom Catalysts for CO2 Electroreduction Reactions

“…The development of non-precious-metal DACs makes sense for CO 2 electrolysis (cathodic compartment), although a precious-metal (e.g., Pt) electrode is often still used for the anodic compartment (i.e., oxidation of water). Furthermore, it has been demonstrated that an electrode with an area of >5 cm 2 required for larger-scale electrolysis of CO 2 could cause severe heat production at a high current density . Along this line, the design of electrocatalysts for CO 2 electrolysis using a low overpotential would be encouraging toward saving energy.…”

“…Furthermore, it has been demonstrated that an electrode with an area of >5 cm 2 required for larger-scale electrolysis of CO 2 could cause severe heat production at a high current density. 142 Along this line, the design of electrocatalysts for CO 2 electrolysis using a low overpotential would be encouraging toward saving energy. Because the development of GDEs is appealing for mass production processes, upgrading the technology of electrolyzers will be inevitable.…”