Molecular Design of Single‐Atom Catalysts for Oxygen Reduction Reaction

Abstract

His thesis mainly focuses on developing graphene-based single-atom catalysts and the surface engineering of Pt-based nanostructures for energy conversion and storage. Xiangfeng Duan received his Ph.D. in physical chemistry from Harvard University and his B.S. degree in chemistry from the University of Science and Technology of China. His research group at UCLA focuses on developing new material systems for highly efficient energy harvesting, conversion, and storage via the rational design and nanoscale integration of distinct materials. Taking advantage of unique 2D materials, he conducts research on the facile and controllable synthesis of novel single atoms catalysts for energy demanding applications and investigates their structure-activity relationships at atomic level to improve their catalytic activity for future application in real-life devices. Yu Huang received her Ph.D. in physical chemistry from Harvard University and her B.S. degree in chemistry from the University of Science and Technology of China.Her research group at UCLA explores the unique technological opportunities that result from the structure and assembly of nanoscale building blocks. Focusing at phenomena that occur at molecular level, she aims to unravel the fundamental principles that govern the synthesis and assembly of nanoscale material. Moreover, she uses such principles to design nanostructures and nanodevices with unique functions and properties to address critical challenges in electronics, energy science, and biomedicine.

Modulating the local coordination environment of single-atom catalysts for enhanced catalytic performance

“…In their study, Pd SA/FeOx could be the best candidates for further applications, which even exhibited better performance than reported Pt SA/FeOx and Ni SA/FeOx. Based on the theoretical studies, further precise characterizations such as coordination number, the second-and higher-shell coordinations were mostly performed by combining experimental XAS spectra and theoretical modelings [31,53]. For example, Jaouen et al reported that the identification of Fe-SA/N4C12, Fe-SA/N4C10, and Fe-SA/N4C12Ox could be indicated by experimental XANES and related theoretical spectra [54].…”

Recent Advances in Single-Atom Electrocatalysts for Oxygen Reduction Reaction

“…By pyrolysis of a bimetallic ZnCo-ZIF with a Zn/Co ratio of 10 at 900°C, Xiao et al for the first time revealed the homonuclear binary Co 2 N 5 configuration in the carbon matrix [159] electrocatalysts by in situ encapsulating Fe(acac) 2 , Fe 2 (CO) 9 , and Fe 3 (CO) 12 in the nanocavity of ZIF-8 during the synthesis of ZIF-8 followed by pyrolysis at 800°C [125]. [11,160,162], including Fe-N 2 , Fe-N 4 -C 8 , Fe-N 4 -C 10 , Fe-N 4 -C 12 , Fe-N 4 Td, Fe-N 5 , and Fe-N 6 . In most cases, single-atom Fe tended to form planar Fe-N 4 moieties by coordinating with four pyrrolic or pyridinic N atoms (Fe-N 4 -C 12 or Fe-N 4 -C 10 , respectively) after treating the Fe, N, and C precursors at high temperature (above 800°C).…”

“…Due to unique empty d orbital structure, atomically dispersed Fe atoms could feature various types of coordination structures and numerous M-N x -C y SAECs have been reported [ 11 , 160 , 162 ], including Fe-N 2 , Fe-N 4 -C 8 , Fe-N 4 -C 10 , Fe-N 4 -C 12 , Fe-N 4 Td, Fe-N 5 , and Fe-N 6 . In most cases, single-atom Fe tended to form planar Fe-N 4 moieties by coordinating with four pyrrolic or pyridinic N atoms (Fe-N 4 -C 12 or Fe-N 4 -C 10 , respectively) after treating the Fe, N, and C precursors at high temperature (above 800°C).…”

Circumventing Scaling Relations in Oxygen Electrochemistry Using Metal–Organic Frameworks

“…[2][3][4] These losses have been attributed to the unfavorable scaling between the binding energies of OXR intermediates, in particular *OOH vs *OH. 2,5,6 Although recent discoveries of low-cost alternatives are encouraging, 7,8 it is likely that their performance is also constrained by similar intrinsic limitations. Despite slight material-specific variations, the robustness of the *OOH vs *OH linear correlation across different materials and computational methods is well-established.…”