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Cost-effective and highly efficient Fe–N–C single-atom catalysts (SACs) have been considered to be one of the most promising potential Pt substitutes for the cathodic oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). Nevertheless, they are subject to severe oxidative corrosion originating from the Fenton reaction, leading to poor long-time durability of PEMFCs. Herein, we propose a MnO_x engineered Fe–N–C SAC (Mn–Fe–N–C SAC) to reduce and even eliminate the stability issue, as MnO_x accelerates the degradation of the H₂O₂ by-product via a disproportionation reaction to weaken the Fenton reaction. As a result, the Mn–Fe–N–C SAC shows an ultralowmore » H₂O₂ yield and a negligible half-wave potential shift after 10000 continuous potential cycles, demonstrating excellent ORR stability. Besides, the Mn–Fe–N–C SAC also shows an improved ORR acti vity compared to the common Fe–N–C SAC. Results show that the MnO_x interacts with the Fe–Nx site, possibly forming Fe–Mn or Fe–O–Mn bonds, and enhances the intrinsic activity of single iron sites. This work provides a method to overcome the stability problem of Fe–N–C SACs while still yielding excellent catalytic activity, thus showing great promise for application in PEMFCs.« less

Atomically dispersed Cu catalyst was designed for highly efficient hydroxylation of aryl iodides under mild conditions.

Single-atom catalysts have emerged as a new frontier in catalysis science. However, their applications are still limited to small molecule activations in the gas phase, the classic organic transformations catalyzed by single-atom catalysts are still rare. Here, we report the use of a single-atom Pd catalyst for the classic Suzuki–Miyaura carbon–carbon coupling reaction under phosphine-free and open-air conditions at room temperature. The single-atom Pd catalyst is prepared through anchoring Pd on bimetal oxides (Pd-ZnO-ZrO₂). The significant synergetic effect of ZnO and ZrO₂ is observed. The catalyst exhibits high activity and tolerance of a wide scope of substrates. Characterization demonstrates thatmore » Pd single atoms are coordinated with two oxygen atoms in Pd-ZnO-ZrO₂ catalyst. The catalyst can be fabricated on a multi-gram scale using a simple in situ co-precipitation method, which endows this catalytic system with great potential in practical applications.« less

In this report, we report the successful incorporation of iron (0) species into a 2, 2'-bipyridine functionalized metal–organic framework (MOF) (UiO-67-bpydc). Considering the limited window size of the MOF, a small molecule, iron pentacarbonyl, was used to introduce iron (0) to coordinate to the backbone of the MOF. The newly generated material contains the iron coordinated linker, Fe(CO)₃(bpydc), which was supported by a series of characterization techniques. DFT calculation was also used to help understand the structure of the formed complex inside the MOF. The MOF structure remained unchanged after the post-synthetic modification, and the resulted material is a greatmore » precursor to generate MOF supported catalyst.« less