Lanthanoid coordination compounds as diverse self-templating agents towards hierarchically porous Fe–N–C electrocatalysts. Issue 21 (30th August 2022)

• Record Type: Journal Article
• Authors: Salton, Itamar; Ioffe, Karina; Burshtein, Tomer Y.; Farber, Eliyahu M.; Seraphim, Nicola M.; Segal, Nofit; Eisenberg, David
• Is Part Of: Materials advances. Volume 3:Issue 21(2022)
• Page Start: 7937
• Page End: 7945
• Publication Date: 2022-08-30
• Subjects: 620.11
• DOI: 10.1039/d2ma00596d
• Languages: English
• ISSNs: 2633-5409

Abstract

Abstract : Templating of rich, complex and useful porosity in carbons is achieved by the pyrolysis of eight lanthanoid frameworks. A better understanding of porogenesis during self-templating helps electrocatalysis, especially bubble removal. Abstract : Pore structure is a critical material property of carbon materials, determining their surface area, active site accessibility, wettability, and efficiency of bubble removal. In the self-templating approach to pore design, inorganic particles form inside a carbon during pyrolysis, templating meso- and macropores. This strategy is simple and economic, yet limited by choice of templating elements and by incomplete understanding of carbon-template interactions. We followed the self-templating process of eight lanthanoid coordination compounds (the iminodiacetates of La 3+, Nd 3+, Sm 3+, Eu 3+, Gd 3+, Tb 3+, Er 3+, and Yb 3+ ), shedding light on the pore structure and the processes that form it. The resulting carbons showed high BET specific surface areas (up to 2700 m 2 g −1 ), hierarchical micro-, meso- and macro-porosity, and lanthanoid-imprinted nitrogen moieties that could be transmetalated to yield atomically dispersed Fe–N x sites. Some of the resulting Fe–N–C materials showed excellent activity towards hydrazine oxidation electrocatalysis, helping to identify several key links between porosity and electrocatalysis, especially the removal of electrode-blocking N2 (g) bubbles. Overall, this detailed investigation expands the toolbox of rational design methods towards rich and useful electrocatalyst porosities.