Secondary doping of Mn/Co bimetallic ZIF-derived catalysts for the oxygen reduction reaction

Abstract

We report a bimetallic catalyst Mn0.1Co0.3/NC-2, which excellent ORR activity in alkaline and acidic electrolytes, due to the increased number of M–Nx active sites by secondary doping and the synergistic effect of the Mn and Co bimetals.

A novel design of superparamagnetic iron oxide-based metal–organic framework for SSI-assisted drug delivery system

“…After ZIF-8 coating, the product presents characteristic diffraction peaks indexed to (011), (002), (112), (022), (013), (222), (233), and (134) planes of ZIF-8 at 7.2°, 10.3°, 12.7°, 14.6°, 16.3°, 18.0°, 24.6°, and 26.6°, respectively. 32,33 This result demonstrates two phases (Fe 3 O 4 -COOH and ZIF-8) in the composite material. The characteristic peaks of Fe 3 O 4 @ZIF-8-CUR are comparable to those of Fe 3 O 4 @ZIF-8, indicating the well-maintained degree of crystallinity of the drug delivery system.…”

“…31 It is now well established from a variety of studies that ZIF-8 is recognized as a common nanocarrier for loading medicine, protein, and DNA. 32–34 Curcumol (CUR), a food source compound isolated from herbal medicine plant, has been reported to exert anticancer effects in multiple tumour cell lines without any side effects. 35 Recent research has shown its therapeutic effects such as inducing receptor-interacting PIPK1/PIPK3 through the JNK-ROS pathway and suppressing hepatocellular carcinoma cell growth, migration, and invasion.…”

Recent Progress and Prospects of Manganese–Nitrogen–Carbon Electrocatalysts for Oxygen Reduction Reaction

“…Metal atoms doping provides a unique platform for studying catalytic reactions with enhanced activity and durability. ,,, The findings demonstrate that Mn–N–C involved with bimetallic atoms substantially enhances electrocatalytic performance compared to Mn–N–C with monometallic atoms. ,, Moreover, the collaborative influence of the two metallic components markedly enhances catalytic efficiency and stability by facilitating electron transfer pathways and distribution. ,, Given the various electronegativity of metal atoms, doping additional metal atoms and N atoms can change the electronic configuration near the carbon framework, improving specific adsorption-free energy of reactants. ,, Consequently, incorporating two metal atoms with distinct catalytic benefits into N-doped carbon materials, uniformly dispersed by the same atom, yields high-performance bimetal electrocatalysts. , Recently, researchers have investigated the introduction of additional transition metal atoms into Mn–N–C to form bimetallic-doped carbon materials, which can alter the electronic configuration of Mn sites and reconfigure unique active sites that differ from monometallic Mn–N–C catalysts. , Additionally, the collaborative influence of bimetal can reduce the energy barrier for ORR and expedite charge transfer, thus improving ORR catalytic process. ,, …”

“…Guo et al introduced a bimetallic catalyst through a secondary doping approach and prepared the carbon catalyst codoped with Mn and Co (Mn 0.1 Co 0.3 /NC-2) (Figure a). XPS analysis confirmed the existence of Mn and Co (Figure (b-c)).…”

“…Energy serves as the fundamental cornerstone of human progress and development . The continuous growth of the population is accompanied by an increase in energy demands. − Nevertheless, the dependence on conventional fossil fuels has led to escalating environmental pollution, encompassing global warming and rising sea levels due to increased carbon dioxide emissions. − Consequently, current research focuses on developing economical and effective technologies for innovative approaches to clean energy conversion and storage, such as water decomposition, metal-air batteries, hydrogen storage and fuel cells. − In metal-air batteries and proton exchange membrane fuel cells, oxygen reduction reaction (ORR), as an important chemical reaction, usually restricts their actual performance. , The ORR generally proceeds through a 4-electron (4e – ) pathway and displays sluggish kinetics, which results in high energy barriers for the reaction. ,− Therefore, it is imperative to advance the development of exceptional electrocatalysts to accelerate the electrochemical ORR kinetics. − Presently, the common commercial catalysts predominantly composed of Pt demonstrate high catalytic performance. , However, the substantial cost of Pt-based catalysts makes them unsuitable to meet future market demands. − Hence, there is an urgent need to explore nonplatinum group (NPG) catalysts with efficient and high performances to reduce the independence of expensive Pt-based materials. − …”