Strong Electronic Interaction of Amorphous Fe₂O₃ Nanosheets with Single‐Atom Pt toward Enhanced Carbon Monoxide Oxidation

Abstract

Platinum-based catalysts are critical to several chemical processes, but their efficiency is not satisfying enough in some cases, because only the surface active-site atoms participate in the reaction. Henceforth, catalysts with single-atom dispersions are highly desirable to maximize their mass efficiency, but fabricating these structures using a controllable method is still challenging. Most previous studies have focused on crystalline materials. However, amorphous materials may have enhanced performance due to their distorted and isotropic nature with numerous defects. Here reported is the facile synthesis of an atomically dispersed catalyst that consists of single Pt atoms and amorphous Fe 2 O 3 nanosheets. Rational control can regulate the morphology from single atom clusters to subnanoparticles. Density functional theory calculations show the synergistic effect resulted from the strong binding and stabilization of single Pt atoms with the strong metal-support interaction between the in situ locally anchored Pt atoms and Fe 2 O 3 lead to a weak CO adsorption. Moreover, the distorted amorphous Fe 2 O 3 with O vacancies is beneficial for the activation of O 2 , which further facilitates CO oxidation on nearby Pt sites or interface sites between Pt and Fe 2 O 3 , resulting in the extremely high performance for CO oxidation of the atomic catalyst.

Single Atom Catalysts: A Review of Characterization Methods

“…The nonsymmetric Pt 5d states, due to the interaction between single atoms and magnetic supports, may play additional roles here. Similar results were also reported by Chen et al [30] who studied amorphous Fe 2 O 3 2D nanosheets variously supporting Pt single atoms, Pt clusters and Pt nanoparticles and found a direct correlation between metal-support charge transfer and their catalytic activity for CO oxidation: the higher the charge transfer, the lower the adsorption energy of CO, the higher the adsorption energy of O 2 , and consequently, the higher the reactivity for CO oxidation. The results also show a nonlinear correlation exists between the d band center of the Pt species and the catalytic properties evidenced.…”

Prototype Atomically Dispersed Supported Metal Catalysts: Iridium and Platinum

“…[ 13 ] A solvothermal method was used with ethylene glycol to form amorphous Fe 2 O 3 nanosheets with abundant oxygen vacancies where atomically dispersed platinum bonded. [ 93 ] Ir(acac) 3 in a zeolite imidazolate framework (ZIF‐8) was heated to yield atomically dispersed iridium bonded to nitrogen atoms (Figure 4b). [ 94 ] Platinum in Y zeolite was synthesized from platinum–ethanediamine complexes in the zeolite crystallization process, and subsequent heating gave atomically dispersed platinum in the zeolite pores (Figure 4d).…”

Recent developments in the use of single-atom catalysts for water splitting

“…Single-atom catalysts (SACs), in which the metal atoms are isolated on supports, have emerged as a new frontier [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Compared to catalysts with nanoparticles and metal clusters, the SACs feature significantly different structures and characteristics, which give them superior activity, selectivity, and durability for many catalytic reactions.…”