Selective surface functionalization generating site-isolated Ir on a MnO_x/N-doped carbon composite for robust electrocatalytic water oxidation

Abstract

Through designing the precursor complex, single Ir atoms can be selectively accommodated in hybrid materials, providing higher stability and activity in electrocatalysis.

Single-Atom Catalysts across the Periodic Table

“…Iridium single-atom catalysts encompass a diverse landscape of hosts. Among the metal oxides, systems with MgAl 2 O 4 (Figure a), , FeO x (Figure b), ,,, MnO 2 (Figure c), and MgO , have been reported. Less frequently used hosts are ZrO 2 (composite with carbon) and Al 2 O 3 .…”

“…Still, to date, rather few studies exist on Ir SACs in comparison to all other late transitions metals (Figure ). Selected cases have been studied using metal oxides, − alongside broader comparisons of several metals. ,,, Besides, Gates et al have put significant effort into understanding MgO and zeolite-supported Ir SACs, − profiting from its affinity to form carbonyl and ethylene complexes. Another outcome of the favorable complex chemistry of Ir, are publications on nuclearity effects using Ir dimers , and tetramers …”

“Nano-garden cultivation” for electrocatalysis: controlled synthesis of Nature-inspired hierarchical nanostructures

“…33 Besides, costly additives and surfactants are oen used for geometry control, and large-scale material preparation is thus challenging. [34][35][36] Electrodeposition is a simple alternative approach of nanofabrication which can be dated back to 1987 in the pioneering work of Martin et al 37 Yet, a template is oen required for the synthesis and plating three-dimensional intricate structures at the nanometric scale remains problematic. Though the coprecipitation approach has recently allowed precise control of the formation of complex micrometer-scale shapes with amazing beauty, downsizing the shape to the nanometer scale is yet impossible.…”

“…Though the coprecipitation approach has recently allowed precise control of the formation of complex micrometer-scale shapes with amazing beauty, downsizing the shape to the nanometer scale is yet impossible. 18,36,38,39 In this work, via coupling the hydrothermal and electrodeposition synthesis approaches under different reaction conditions, we managed to design and prepare a number of Co(OH) 2based nano-architectures that resemble various items in a garden ("soil", "ake", "sprout", "grass", "ower" and "leaf"). Such patterns can be fully phosphidated, forming CoP structures.…”

Iridium‐based electrocatalysts toward sustainable energy conversion

“…6 Not limited to the Ir single-atoms or nanoparticles, the rational designs of Ir-based alloys, oxides, or other nanocomposites are also important to further applications. According to the recent reports, the syntheses of Irbased electrocatalysts can be achieved by hydrothermal method, 7 impregnation, 8 wet chemical reduction, 2,9,10 colloidal method, 11 carbonization, 12 laser etching, 13 electrochemical deposition method, 14 microwave-assisted method, 15 spray freeze drying method, 16,17 sol-gel method, 18 and pyrolysis treatment. [19][20][21][22][23] By these nanoengineering methods, various Ir-based electrocatalysts with desired structures can be successfully designed.…”