Heterogeneous single-atom catalysts for energy process: recent progress, applications and challenges

Abstract

Single-atom catalysts (SACs) with high activity, unique selectivity, and nearly 100% atom utilization efficiency are promising for broad applications in many fields. This review aims to provide a summary of the current development of SACs and point out their challenges and opportunities for commercial applications in the energy process. The discussion starts with an introduction of various types of SACs materials, followed by typical SACs synthetic methods with concrete examples and commonly used characterization methods. The state-of-the-art synthesis methods, whereby SACs with stabilized single metal atoms on the substrate without migration and agglomeration could be obtained, are emphasized. Next, we give an overview of different types of substrates and discuss the effects of substrate species on the structure and properties of SACs. Then we highlight the typical applications of SACs and the remaining challenges. Finally, a perspective on the opportunities for the development of SACs for future commercial applications is provided.

Defect Tailoring in the Metal–Organic Framework Cu (BDC-NH2) for the High-Efficiency Photocatalytic Reduction of Cr(VI)

“…However, Cr­(III) is an essential trace element for human health with no toxicity. , Up to now, many techniques including membrane filtration, ion change, adsorption, and reduction of Cr­(VI) to Cr­(III) have been developed to remove Cr­(VI) from industrial wastewater. − Among these techniques, the reduction of Cr­(VI) to Cr­(III) is well recognized as the best strategy due to its advantages of being most compatible and cost-effective . In contrast to traditional reduction techniques such as microreduction, chemical reduction, and electrochemical reduction, the photocatalytic reduction of Cr­(VI) to Cr­(III) has the advantages of high efficiency, low cost, and being free of any hazardous chemical formation. , Metal–organic frameworks (MOFs), as the emerging photocatalysts, were widely utilized to efficiently reduce Cr­(VI) into Cr­(III) due to their features of desirable topologies, crystallinity, porous structure, high surface areas, and pore volume. − For example, UiO-66-NH 2 and its derivatives exhibit outstanding performance for photocatalytic Cr­(VI) reduction . Though metal–organic frameworks (MOFs) have many merits, they still suffer from the high recombination rate of the photoinduced electrons and holes and limited light absorption .…”

Electrochemically nitrate remediation by single-atom catalysts: advances, mechanisms, and prospects

“…[19][20][21] . By achieving nearly 100% atom utilization efficiency, Single-atom catalysts (SACs) lower the cost in synthesizing effective catalysts and provide model systems to bridge the gap between heterogeneous and homogeneous catalysts [22][23][24][25] . Due to their unique electronic properties, SACs have demonstrated the superior activities and capabilities in facilitating the electrocatalytic activities by rational structural design with numerous applications of NITRR [26] , hydrogen evolution (HER) [27,28] , oxygen evolution (OER) [29,30] , oxygen reduction (ORR) [31][32][33][34] , carbon dioxide reduction (CO 2 RR) [35][36][37][38] , nitrogen reduction (NRR) [39] , and carbon-nitrogen coupling reactions (C-N coupling) [40] .…”

Copper vulcanization realizes selective carbon dioxide reduction to formate

“…Electrocatalytic carbon dioxide reduction (CO 2 RR) has recently attracted increasing attention for reducing CO 2 emission and converting CO 2 to value-added chemicals with intermittent electric energy. [1][2][3][4][5] In principle, CO 2 can be converted into carbon monoxide (CO), 6,7 methane (CH 4 ), [8][9][10] formate (HCOOH), [11][12][13] ethylene (C 2 H 4 ), 14 acetic acid (CH 3 COOH), 15 and ethanol (CH 3 CH 2 OH) [16][17][18] through the CO 2 RR. Over the past few decades, great efforts have been devoted to developing electrocatalysts to selectively reduce CO 2 to value-added products, especially C 2+ products.…”