Mn−O Covalency Governs the Intrinsic Activity of Co‐Mn Spinel Oxides for Boosted Peroxymonosulfate Activation

Abstract

Transition metal (TM)-based bimetallic spinel oxides can efficiently activate peroxymonosulfate (PMS) presumably attributed to enhanced electron transfer between TMs,b ut the existing model cannot fully explain the efficient TM redoxc ycling. Here,w ed iscover ac ritical role of TM À O covalency in governing the intrinsic catalytic activity of Co 3Àx Mn x O 4 spinel oxides.E xperimental and theoretical analysis reveals that the Co sites significantly raises the Mn valence and enlarges MnÀOc ovalency in octahedral configuration, thereby lowering the charge transfer energy to favor Mn Oh-PMS interaction. With appropriate Mn IV /Mn III ratio to balance PMS adsorption and Mn IV reduction, the Co 1.1 Mn 1.9 O 4 exhibits remarkable catalytic activities for PMS activation and pollutant degradation, outperforming all the reported TM spinel oxides.T he improved understandings on the origins of spinel oxides activity for PMS activation may inspire the development of more active and robust metal oxide catalysts.

Epitaxially Grown Heterostructured SrMn3O6−x‐SrMnO3 with High‐Valence Mn3+/4+ for Improved Oxygen Reduction Catalysis

“… [16] The higher average oxidation state of Mn in SMO x ‐SMO (5.05 eV) was also evident in the smaller separation of the Mn 3s values compared to SMO x ‐MO (5.20 eV, Figure 2 c). [17] Deconvolution of O 1s XPS spectra revealed the presence of several oxygen species (Figure 2 d). [18] The peaks at 529.4, 530.0, 531.4 and 532.4 eV were assigned to lattice oxygen, terminal oxygen, Mn‐OH and chemically adsorbed oxygen, respectively [19] .…”

Mineral Modulated Single Atom Catalyst for Effective Water Treatment

“…Peroxymonosulfate (PMS)‐based advanced oxidation processes (AOPs) have sparked broad interest in environmental remediation because of their in situ generation of oxidizing species, such as hydroxyl radical ( • OH), sulfate radical (SO 4 •− ), singlet oxygen ( 1 O 2 ), and superoxide anion radical (O 2 •− ). [ 1–6 ] Although cobalt ion (Co 2+ ) has been regarded as the most efficient species for homogeneous PMS activation, the potential environmental toxicity and carcinogenicity of residual Co 2+ severely impede its global scale application. [ 7 ] Cobalt oxides such as Co 3 O 4 can address above issues, but the relatively low activation efficiency (turnover frequencies (TOF) per Co atom basis) compared to Co 2+ remains challenging.…”

Stabilizing V2O3 in carbon nanofiber flexible films for ultrastable potassium storage

“…So far, a variety of materials have been explored and used as anodes for potassium-ion batteries, such as carbon-based materials, 19–22 alloys, 23,24 organic materials, 25,26 transition metal sulfides 27–32 /oxides, 33–37 and so on. Compared with other materials, vanadium oxide (V 2 O 3 ) shows great potential for energy storage due to the open tunnel structure of 3D V–V frameworks, low cost and multi-electron transfers.…”