Transition‐Metal Oxides/Carbides@Carbon Nanotube Composites as Multifunctional Electrocatalysts for Challenging Oxidations and Reductions

Abstract

Ther apid development of renewable-energy technologies such as water splitting, rechargeable metal-air batteries, and fuel cells requires highly efficient electrocatalysts capable of the oxygen-reduction reaction( ORR) and the oxygen-evolution reaction( OER). Herein, we report af acile sonication-driven synthesis to deposit the molecular manganese vanadium oxide precursor [Mn 4 V 4 O 17 (OAc) 3 ] 3À on multiwalled carbon nanotubes (MWCNTs). Thermal conversion of this composite at 900 8Cg ives nanostructured manganese vanadium oxides/carbides, which are stably linked to the MWCNTs. The resulting composites show excellent electrochemical reactivity for ORR and OER, and significant reactivi-ty enhancements compared with the precursors and aP t/C reference are reported.N otably,e ven under harsh acidic conditions, long-term OER activity at low overpotential is reported. In addition, we report exceptional activity of the composites for the industrially important Cl 2 evolution from an aqueous HCl electrolyte. The new composite material showsh ow molecular deposition routes leading to highly active and stable multifunctional electrocatalysts can be developed.T he facile design could in principle be extended to multiple catalystc lasses by tuning of the molecular metal oxide precursor employed.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.Scheme1.Schematicillustration of the synthesized composites( MC x / MO x = Mn 7 C 3 /V 8 C 7 /MnO).Figure 1. PowderX-ray diffraction of a) composites prepared at different temperatures and b) 1-900 with specified peaks.

Recent Advances in Non‐Precious Metal‐Based Electrodes for Alkaline Water Electrolysis

“…Furthermore, metal carbides have also shown potential in oxygen evolution . 2D molybdenum carbide nanomeshes requiring 180 mV overpotential at the current density of 10 mA cm −2 were prepared by Wang et al, and Streb prepared MnV carbides with superior OER activity compared with noble metal catalyst . The transition metal derivates with tunable composition and structure, provide a great amount of opportunities for the design and synthesis of cost‐effective electrocatalysts.…”

Top-down synthesis of polyoxometalate-like sub-nanometer molybdenum-oxo clusters as high-performance electrocatalysts

“…by CO or methanol. 4 Therefore, earth-abundant transition-metal based catalysts, such as transition-metal oxides, 5,6 carbides and nitrides, 7,8 have been explored as technologically viable alternative ORR catalysts. However, the complexity of many of these catalytic composites together with a lack of suitable structural models to explore structure-function-activity-stability relationships is a signicant challenge in the eld.…”

“…19,20 In contrast, POMs have been used as molecular precursors for nanostructured metal oxides and carbides as highly efficient ORR electrocatalysts. 5,7,25,26 This suggests that fundamental challenges related to the molecular nature of POMs prevent their wider development for ORR electrocatalysis: these challenges include poor mechanical and electrical linkage between POMs and electrodes, resulting in leakage during operation and high electrical resistance, i.e. poor catalytic performance.…”

Design and construction of bi-metal MOF-derived yolk–shell Ni2P/ZnP2 hollow microspheres for efficient electrocatalytic oxygen evolution

“…In recent years, various transition metal (TM) phosphides, 10 oxides, 11 chalcogenides, 12 borides, 13 nitrides 14 and their composites 15 have emerged as effective OER catalysts. Among these cost-efficient catalysts, TM phosphides are regarded as catalysts with superior electrocatalytic activity and stability in alkaline media to effectively promote the OER process in terms of thermodynamics and kinetics.…”