Emerging Carbon‐Based Heterogeneous Catalysts for Electrochemical Reduction of Carbon Dioxide into Value‐Added Chemicals

Abstract

The electrocatalytic reduction of CO2 provides a sustainable way to mitigate CO2 emissions, as well as store intermittent electrical energy into chemicals. However, its slow kinetics and the lack of ability to control the products of the reaction inhibit its industrial applications. In addition, the immature mechanistic understanding of the reduction process makes it difficult to develop a selective, scalable, and stable electrocatalyst. Carbon‐based materials are widely considered as a stable and abundant alternative to metals for catalyzing some of the key electrochemical reactions, including the CO2 reduction reaction. In this context, recent research advances in the development of heterogeneous nanostructured carbon‐based catalysts for electrochemical reduction of CO2 are summarized. The leading factors for consideration in carbon‐based catalyst research are discussed by analyzing the main challenges faced by electrochemical reduction of CO2. Then the emerging metal‐free doped carbon and aromatic N‐heterocycle catalysts for electrochemical reduction of CO2 with an emphasis on the formation of multicarbon hydrocarbons and oxygenates are discussed. Following that, the recent progress in metal–nitrogen–carbon structures as an extension of carbon‐based catalysts is scrutinized. Finally, an outlook for the future development of catalysts as well as the whole electrochemical system for CO2 reduction is provided.

A Disquisition on the Active Sites of Heterogeneous Catalysts for Electrochemical Reduction of CO2 to Value‐Added Chemicals and Fuel

“…The introduction of dopants such as electron donating B and electron‐withdrawing N is shown to generate active sites within carbon nanomaterials, allowing these catalysts to exhibit prominent activity during CO 2 RR. In addition to dopants, defects, functional groups and structure of carbon are reported to play a beneficial role for CO 2 RR . As a consequence, this following section would look into the classes of active sites in carbon nanomaterials that are commonly reported for CO 2 RR.…”

2020 Roadmap on Carbon Materials for Energy Storage and Conversion

“…The catalytic performances toward the CO 2 RR are closely related to the N‐doping types. Precise control synthesis of N‐doped atoms with a specific configuration helps to demine the most active doping type, which is unfortunately difficult to achieve by conventional synthesis route . A groundbreaking work for preparing highly oriented pyrolytic graphite (HOPG) with well‐controlled N‐doping types was accomplished by Guo et al.…”

Metal‐Modulated Nitrogen‐Doped Carbon Electrocatalyst for Efficient Carbon Dioxide Reduction

“…Carbon‐based catalysts have been widely used in all kinds of electrochemical reactions for energy conversion on the basis of their tunable surface chemistry, structural diversity, large electron mobility and low cost . Among these reactions, electrochemical CO 2 reduction reaction (CDRR) attracted great research interests recently because it is an approach to consuming CO 2 and producing value‐added fuels or chemicals concurrently .…”

“…Carbon-based catalysts have been widely used in all kinds of electrochemical reactions for energy conversion on the basis of their tunable surface chemistry, structural diversity, large electron mobility and low cost. [1][2][3][4] Among these reactions, electrochemical CO 2 reduction reaction (CDRR) attracted great research interests recently because it is an approach to consuming CO 2 and producing value-added fuels or chemicals concurrently. [5][6][7] Expectedly, heteroatom-doped carbons, such as single doping carbons (NÀ C, [8][9][10][11] FÀ C [12] ) and multiple doping carbons (SiÀ CÀ N, [13] NSÀ C, [14] Fe(Ni, Co)À NÀ C, [15][16][17][18] Ni (Mn)À FeÀ N [19,20] ), and defective carbons [21][22][23] were reported as electrocatalysts in this burgeoning field.…”

“…It is well-known that modulation of heteroatom dopants in carbon-based catalysts relies on synthesis approaches and precursors used. For synthesis of common N-doped carbon catalysts, three approaches by etching reaction of carbon with external N sources (e. g. NH 3 ), [26,27] direct pyrolysis conversion of N-containing precursors (e. g. MOF or polymer), [28][29][30] or in-situ growth of NÀ C layers from N-containing gaseous species [31,32] could be used. Each approach leads to different N chemical states in the synthetic materials.…”