Zihao Hu,Xiaoying Zhou,Tiantian Zhang,Zuliang Wu,Jing Li,Wei Wang,Erhao Gao,Jiali Zhu,Shuiliang Yao
Catalytic combustion has been considered the effective way to oxidize carbon monoxide (CO). It is both crucial and challenging to develop highly-active monolithic catalysts at lower temperatures for industrial applications. This study synthesized a monolithic Co 3 O 4 /Mn 3 O 4 -NF catalyst by the generation of in-situ metal–organic framework (MOF-74)-derived Co 3 O 4 /Mn 3 O 4 on nickel foam (NF). The resulting Co 3 O 4 /Mn 3 O 4 -NF catalyst demonstrated superior low-temperature CO oxidation performance, and the T 90 temperature was 20 °C. The enhanced activity is associated with the increased oxygen vacancy concentration, abundant Co 3+ , Mn 2+ + Mn 3+ , and surface-adsorbed oxygen species (O ads ), as well as low-temperature reducibility. In addition, operando DRIFTS analysis revealed that the surface of this as-prepared catalyst possessed abundant terminal-type oxygen (M O), facilitating CO adsorption and catalytic oxidation. This pioneering study introduces a paradigm-shifting insight: the effectiveness of non-noble metal oxide catalysts can now compete with, and in some cases, outperform their noble metal counterparts. This breakthrough is set to transform the industry, presenting a compelling alternative to conventional noble metal catalysts and propelling the evolution of state-of-the-art environmental conservation technologies.
s Polymer catalyst electrodes have good electrical conductivity, high mechanical strength and other characteristics, which have good prospects in the future market of green and low carbon. In this paper, the electrode of PEDOT polymer catalyst is studied, and the electrochemical performance of the electrode is improved by doping different metals. This study describes the design of PEDOT-Co 3 O 4 @Mn 3 O 4 /Mn 2 O 3 catalysts by simple solvothermal synthesis. As a catalyst in the hydrogen evolution reaction (HER), the overpotential of the same polarization curve is much smaller than that of PEDOT, with a Tafel slope of 118.21 mV dec ‐1 , by electrochemical and characterization analysis. In the test of the supercapacitor performance, it has a large specific capacitance of 1298.5 Fg -1 and a small electrical impedance (0.21 Ω). After 2000 cycles of CV test, the capacitance remains 87.76 %, and the curve shape is stable, which proves that it has good electrochemical performance. Our results confirm the materials have great application prospects in HER and capacitors.
Zinc-air batteries (ZABs) with high energy density and safety are promising as next-generation energy storage systems, while their applications are severely hindered by the sluggish reaction kinetic of air cathodes. Developing a bifunctional catalyst with high activity and durability is an effective strategy to address the above challenges. Herein, a Co 3 O 4 /Mn 3 O 4 nanohybrid with heterointerfaces is designed as advanced cathode catalyst for ZABs. Density functional theory calculations show the heterogeneous interface between Co 3 O 4 /Mn 3 O 4 can improve the dynamics of carrier transport and thus enhancing the catalytic activity and durability. The Co 3 O 4 /Mn 3 O 4 catalyst anchored on reduced graphene oxide (rGO) exhibits high oxygen reduction reaction (ORR) activity with a half-wave potential of 0.86 V, and excellent oxygen evolution reaction (OER) activity with the potential of 1.59 V at 10 mA cm −2 , which are comparable to the commercial noble metal catalysts. The improved ORR/OER catalytic activity is ascribed to the synergistic effect of heterointerfaces between Co 3 O 4 and Mn 3 O 4 as well as the improved conductivity and contact area of oxygen/catalysts/electrolytes three-phase interface by rGO. Furthermore, a home-made ZAB based on Co 3 O 4 /Mn 3 O 4 /rGO shows a high open circuit voltage of 1.54 V, a large power density of 194.6 mW cm −2 and good long-term cycling stability of nearly 400 h at 5 mA cm −2 , which affords a promising bifunctional oxygen catalyst for rechargeable ZABs.
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