Single‐Atom Catalysts: A Sustainable Pathway for the Advanced Catalytic Applications

Abstract

In order to achieve these goals, it is of fundamental importance to design new catalysts that enable new benign routes to produce/ store and convert renewable energies and to obtain chemicals from waste. [3][4][5] We need to design new chemical pathways that replace traditional petrochemicalbased routes, considering new platform molecules, possibly derived by renewable resources such as agriculture/municipal wastes. This transition must fully involve the energy sector, with the entire redefinition of the pool of energy vectors for transportations, building heating systems, and power production. As the burning of fossil fuels and biomass are not anymore compatible with the dramatic increasing air pollution and global warming.To achieve all these targets, we will need to design nontoxic, earth-abundant, and less-expensive, highly efficient, and selective catalysts that can work under mild reaction conditions without producing significant waste. [6,7] Catalytic activity and selectivity are enabled via the many factors such as accessibility of active sites, interaction with the surface, i.e., varying support and coordinating sphere, composition of metals (bimetallic and many-metallic), size and shape; and chemical states of active sites which can to tailored via developing 2D catalyst [8][9][10] or via developing single atomic sites stabilized on hollow A heterogeneous catalyst is a backbone of modern sustainable green industries; and understanding the relationship between its structure and properties is the key for its advancement. Recently, many upscaling synthesis strategies for the development of a variety of respectable control atomically precise heterogeneous catalysts are reported and explored for various important applications in catalysis for energy and environmental remediation. Precise atomic-scale control of catalysts has allowed to significantly increase activity, selectivity, and in some cases stability. This approach has proved to be relevant in various energy and environmental related technologies such as fuel cell, chemical reactors for organic synthesis, and environmental remediation. Therefore, this review aims to critically analyze the recent progress on single-atom catalysts (SACs) application in oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, and chemical and/or electrochemical organic transformations. Finally, opportunities that may open up in the future are summarized, along with suggesting new applications for possible exploitation of SACs.

Atomically Defined Undercoordinated Copper Active Sites over Nitrogen‐Doped Carbon for Aerobic Oxidation of Alcohols

“…[21][22][23][24][25] Moreover, SACs have been found to be effective in bridging homogeneous and heterogeneous catalysis. [26][27][28][29] Selective aerobic oxidation of alcohols offers an attractive means to address challenges in the modern chemical industry, but the development of nonnoble metal catalysts with superior efficacy for this reaction remains a grand challenge. Here, this study reports on such a catalyst based on atomically defined undercoordinated copper atoms over nitrogen-doped carbon support as an efficient, durable, and scalable heterogeneous catalyst for selective aerobic oxidation of alcohols.…”

Air Electrodes for Flexible and Rechargeable Zn−Air Batteries

“…Transition metal and nitrogen atomically doped carbon materials (M−N−C) have attracted numerous attention in recent years due to their novel structures. [ 133–139 ] In metal‐doped carbon materials, M−N x species (M: Fe, Co or Mn) embedded in carbon matrix have been widely reported as the active sites for the ORR, [ 140–144 ] which shows a similar activity as Pt/C for O 2 adsorption and O═O bond breaking in alkaline media. [ 145–148 ] M−N−C materials also exhibited excellent OER properties, resulting from the enhanced electron transfer through the tight binding of metal atoms to carbon and the redistribution of electron state around active sites.…”

Coordination modulation of iridium single-atom catalyst maximizing water oxidation activity

“…Single-atom catalysts (SACs) provide a promising option to significantly reduce the utilization amount of precious metal catalysts by maximizing the atom-efficiency of precious metal elements in catalyst materials 16 – 21 . Recently, tremendous efforts have been devoted to developing efficient SACs for suppressing the OER overpotentials and improving the reaction kinetics for electrochemical water splitting 22 – 25 . It has been proved that the utilization of SACs could significantly improve the intrinsic activity of precious metal elements for the OER process and result in high mass activity 24 , 26 , 27 .…”