Successive Redox Research Articles

Multiple Electron Transfers Enable High-Capacity Cathode Through Stable Anionic Redox.

Single-electron transfer, low alkali metal contents, and large-molecular masses limit the capacity of cathodes. This study uses a cost-effective and light-molecular-mass orthosilicate material, K2FeSiO4, with a high initial potassium content, as a cathode for potassium-ion batteries to enable the transfer of more than one electron. Despite the limited valence change of Fe ions during cycling, K2FeSiO4 can undergo multiple electron transfers via successive oxygen anionic redox reactions to generate a high reversible capacity. Although the formation of O‒O dimers in K2FeSiO4 occur upon removing large amounts of potassium, the strong binding effect of Si on O mitigates irreversible oxygen release and voltage degradation during cycling. K2FeSiO4 achieves 236 mAh g-1 at 50mA g-1, with an energy density of 520Wh kg-1, which can be comparable with commercial LiFePO4 materials. Moreover, it also exhibits 1400 stable cycles under high-current conditions. These findings enhance the potential commercialization prospects for potassium-ion batteries.

Tailor-made anodically coloring organic-inorganic hybrid electrochromic materials derived from phenothiazine cores

Electrochromic materials (ECMs) are crucial for the advancement of electrochromic devices (ECDs). While cathodically coloring ECMs have been extensively studied, their anodically coloring counterparts have received less attention. In this study, we present a novel organic molecule based on inexpensive phenothiazine derivatives, which exhibit promising anodically coloring electrochromic properties. These properties are characterized through combined theoretical calculations and experiments. By introducing two methoxy substituents, the reactive 3,7-positions of the phenothiazine core are protected, enhancing electrochemical stability and introducing new optical properties. Additionally, the molecule is further functionalized with a phosphonic acid anchoring group to create an organic-inorganic hybrid electrochromic film. The resulting film undergoes two successive one-electron redox reactions, transitioning from transparent to greenish-blue and then to blue, with moderate optical contrasts. Notably, the film displays a rapid response time of less than 1 second and an impressive coloration efficiency of approximately 470 cm²/C for the first redox reaction. Furthermore, the film demonstrates exceptional long-term stability, with over 2,000 cycles of reversibility, surpassing any previous findings. These results emphasize the significance of tailor-made design principles for anodically coloring ECMs, which are crucial for the advancement of ECDs and optoelectronic applications..

Total Synthesis of Ryanodane Diterpenoids Garajonone and 3-epi-Garajonone.

Ryanodane diterpenes are structurally complex natural products that are well-known for their high degree of oxidation and the challenges associated with synthesizing them within the terpene class. Herein, we present a two-stage synthetic strategy that draws inspiration from the broad biosynthesis of terpenes, allowing us to achieve the first chemical synthesis of garajonone, a ryanodane diterpenoid that occurs naturally at low abundance, as well as its epimer, 3-epi-garajonone. The key to this success lies in the rapid construction of the carbon framework of the target molecule by employing an early-stage palladium-catalyzed Heck/carbonylative esterification cascade annulation, followed by successive late-stage selective redox manipulation to establish the desired oxidation state of the molecule. This research not only showcases the synthesis of garajonone and its epimer but also provides a platform for the chemical synthesis of other members and analogs of this complex diterpenoid family.

Improved morphological stability of NiFe2O4 via Sr doping for chemical looping hydrogen production

As a new hydrogen production technology, chemical looping hydrogen production has the advantage of internal CO2 separation. NiFe2O4 is considered as promising oxygen carrier material for chemical looping hydrogen production due to the high oxygen carrying capacity and low cost. However, rapid redox performance fading caused by structure degradation and interface instability in successive redox reactions that led fto poor stability, and seriously limited the practical application of NiFe2O4 in chemical looping hydrogen production. Herein, we reported a method for improving the morphological stability of NiFe2O4 through Sr doping. NiFe2O4 samples containing different SrO contents (2 wt%, 5 wt% and 8 wt%) were prepared by a simple mechanical mixing method. A series of characterization analysis results showed that adding an appropriate amount of Sr could significantly improve the microstructure, increase the oxygen vacancy concentration and inhibit the phase segregation of NiFe2O4. The NiFe-5Sr presented the largest BET surface area (24.63 m2/g) and highest concentration of oxygen vacancies (77.49 %). NiFe-0Sr and NiFe-2Sr experienced severe phase segregation during continuous cyclic reactions, resulting in significant surface sintering and deactivation. During 20 redox cycles, NiFe-5Sr presented the highest hydrogen yield (around 10 mmol/g) and stable surface morphology. The research results indicated that the optimal doping amount for SrO was 5 %.

Redox Concomitant Formation Method for Fabrication of Cu(I)-MOF/Polymer Composites with Antifouling Properties.

Marine biofouling, which is one of the technical challenges hindering the growth of the marine economy, has been controlled using cuprous oxide (Cu2O) nanoparticles due to the exceptional antifouling properties of Cu(I) ions. However, Cu2O nanoparticles have encountered bottlenecks due to explosive releases of Cu+ ions, high toxicity at elevated doses, and long-term instability. Here, we present a novel method called Redox Concomitant Formation (RCF) for fabricating a hierarchical Cu(I) metal-organic framework polypyrrole (Cu(I)-MOF/PPy) composite. This method enables in situ phase transition via successive redox reactions that change the chemical valence state and coordination mode of Cu(II)-MOF, resulting in a new structure of Cu(I)-MOF while creating a PPy layer surrounded by the hierarchical structure. Owing to the steady release of Cu+ ions from the Cu(I) sites and photothermal properties of PPy, Cu(I)-MOF/PPy exhibits superior and broad-spectrum resistance to marine bacteria, algae, and surface-adhered biofilms in complex biological environments, as well as long-term stability, resulting in 100 % eradication efficiency under solar-driven heating. Mechanistic insights into successive structural redox reactions and formation using the RCF method are provided in detail, enabling the fabrication of novel MOFs with the desired composition and structure for a wide range of potential applications.

Redox Concomitant Formation Method for Fabrication of Cu(I)−MOF/Polymer Composites with Antifouling Properties

AbstractMarine biofouling, which is one of the technical challenges hindering the growth of the marine economy, has been controlled using cuprous oxide (Cu2O) nanoparticles due to the exceptional antifouling properties of Cu(I) ions. However, Cu2O nanoparticles have encountered bottlenecks due to explosive releases of Cu+ ions, high toxicity at elevated doses, and long‐term instability. Here, we present a novel method called Redox Concomitant Formation (RCF) for fabricating a hierarchical Cu(I) metal–organic framework polypyrrole (Cu(I)−MOF/PPy) composite. This method enables in situ phase transition via successive redox reactions that change the chemical valence state and coordination mode of Cu(II)−MOF, resulting in a new structure of Cu(I)−MOF while creating a PPy layer surrounded by the hierarchical structure. Owing to the steady release of Cu+ ions from the Cu(I) sites and photothermal properties of PPy, Cu(I)−MOF/PPy exhibits superior and broad‐spectrum resistance to marine bacteria, algae, and surface‐adhered biofilms in complex biological environments, as well as long‐term stability, resulting in 100 % eradication efficiency under solar‐driven heating. Mechanistic insights into successive structural redox reactions and formation using the RCF method are provided in detail, enabling the fabrication of novel MOFs with the desired composition and structure for a wide range of potential applications.

Deactivation of iron particles during combustion and reduction

Iron is a promising carbon-free renewable energy carrier to replace fossil fuels. However, during a redox cycle, iron may experience deactivation due to structural changes, which can shorten the cycle lifetime. In this work, deactivation of iron particles in terms of changes in reactivity and morphology during the oxidation and reduction process was investigated, under both fixed-bed and suspension conditions. Simple thermal treatment in an inert atmosphere at 1200 °C had no influence on the reactivity of particles towards oxidation, even at long exposure resulting in mild agglomeration. In fixed-bed oxidation at 600 to 1100 °C, solid sintering was found to be rapid and severe at higher temperatures. However, the sintering showed no influence on the reactivity of particles towards H2 under slow-heating conditions in a TGA. In pulverized-fuel combustion in a drop tube reactor, the intensive combustion and heat release led to melting of particles and morphology change from irregular to spherical. As the reactor temperature was increased from 800 to 1200 °C, the particle reactivity in terms of reduction degree (fractional conversion from Fe2O3 to Fe) slightly decreased from 78 % to 72 %, possibly related to a minor loss of surface area. TGA experiments involving successive redox cycles showed a steady decline in reduction reactivity (750 °C, 2.5 % H2), slightly enhanced by agglomeration, while the oxidation degree (950 °C or 1200 °C, 21 % O2) remained constant. The present work indicates that both deactivation and loss of iron due to evaporation may serve to limit the energy release in iron combustion over extended cycles.

Efficient degradation of norfloxacin via MnCo-LDH/sepiolite activating peroxymonosulfate: Performance, mechanism and degradation pathway

In this study, MnCo layered double hydroxide/sepiolite (MnCo-LDH/sepiolite) as PMS catalyst were synthesized using a simple water bath method. The results indicated that the composite exhibited the highest norfloxacin (NF) removal efficiency (90.14 % in 40 min), and its reaction rate constant (0.2049 min-1) was 2.0 times higher than that of pure MnCo-LDH. Compared with MnCo-LDH, MnCo-LDH/sepiolite catalyst had a larger specific surface area and pore volume which can provide more abundant active sites thereby improving the NF degradation performance. In addition, EPR and quenching experiments results revealed that SO4•- and 1O2 were the main active substances. Moreover, the successive redox of Mn and Co species contributed to the main driving force to effectively activate PMS. Furthermore, the possible catalytic mechanisms and NF degradation pathways were systematically analyzed. Overall, this study provides a new strategy for developing an economical, efficient and environmentally friendly PMS catalyst for wastewater treatment.

Optimizing the sulfur-resistance and activity of perovskite oxygen carrier for chemical looping dry reforming of methane

Perovskite oxides has been attracted much attention as high-performance oxygen carriers for chemical looping reforming of methane, but they are easily inactivated by the presence of trace H2S. Here, we propose to modulate both the activity and resistance to sulfur poisoning by dual substitution of Mo and Ni ions with the Fe-sites of LaFeO3 perovskite. It is found that partial substitution of Ni for Fe substantially improves the activity of LaFeO3 perovskite, while Ni particles prefer to grow and react with H2S during the long-term successive redox process, resulting in the deactivation of oxygen carriers. With the presence of Mo in LaNi0.05Fe0.95O3−σ perovskite, H2S preferentially reacts with Mo to generate MoS2, and then the CO2 oxidation can regenerate Mo via removing sulfur. In addition, Mo can inhibit the accumulation and growth of Ni, which helps to improve the redox stability of oxygen carriers. The LaNi0.05Mo0.07Fe0.88O3−σ oxygen carrier exhibits stable and excellent performance, with the CH4 conversion higher than 90% during the 50 redox cycles in the presence of 50 ppm H2S at 800 °C. This work highlights a synergistic effect in the perovskite oxides induced by dual substitution of different cations for the development of high-performance oxygen carriers with excellent sulfur tolerance.

Exceeding Three-Electron Reactions in Polyanionic Cathode To Achieve High-Energy Density for Sodium-Ion Batteries.

Activating multielectron reactions of sodium superionic conductor (NASICON)-type cathodes toward higher energy density remains imperative to boost their application feasibility. However, multisodium storage with high stability is difficult to achieve due to the sluggish reaction kinetics, irreversible phase transitions, and negative structural degradation. Herein, a kind of NASICON-type Na2.5V1.5Ti0.5(PO4)3/C (NVTP-0.5) hierarchical microsphere consisting of abundant primary nanoparticles is designed, realizing a reversible 3.2-electron reaction with high stability. The optimized NVTP-0.5 cathode demonstrates an ultrahigh discharge capacity of 192.42 mAh g-1, energy density of up to 497.3 Wh kg-1 at 20 mA g-1, and capacity retention ratio of 94.1% after 1000 cycles at 1 A g-1. Additionally, the NVTP-0.5 cathode delivers excellent tolerance to extreme temperatures while also achieving a high-energy density of 400 Wh kg-1 (based on the cathode mass) in a full-cell configuration. Systematic in situ/ex situ analysis results confirm the multisodium storage processes of NVTP-0.5 involving successive redox reactions (V2+/V3+, Ti3+/Ti4+, and V3+/V4+ redox couples) and reversible structure evolution (solid-solution and biphasic mechanisms), which contribute to the high capacity and excellent cycling stability. This work indicates that the rational regulation of components with different functions can unlock more possibilities for the development of NASICON-type cathodes.

In situ and ex situ investigation on the product films evolution of pipeline steel under AC interference and high cathodic protection conditions

An in situ Raman measurement set-up coupled with AC interference and CP circuits was developed to provide more intuitive detection data for combined action AC and CP corrosion processes. Combined with XPS, AFM and other ex situ surface analyses and electrochemical tests, the evolution of composition, structure and electrochemical properties of surface film is studied. Initially, a passive film is formed on specimen surface, which undergoes successive redox processes. Eventually, the passive film evolves into magnetite and rust, and hydrogen evolution produces mechanical damage to rust layer. Based on this, the model for the evolution of AC corrosion is constructed.

Tailored SrFeO3-δ for chemical looping dry reforming of methane

Chemical looping dry reforming of methane (CL-DRM) is a highly efficient process that converts two major greenhouse gases (CH4 and CO2) into syngas ready for the feedstock of liquid fuel production. One of the major obstacles facing this technology now is creating oxygen carriers that are stable and reactive. We fabricated high-performance Sr0.98Fe0.7Co0.3O3-δ perovskite-structured oxygen carrier by combining A-site defects and B-site doping of SrFeO3-δ. During isothermal CL-DRM tests at 850 °C, Sr0.98Fe0.7Co0.3O3-δ achieved 87% CH4 conversion and 94% CO selectivity in the CH4 partial oxidation reaction, followed by a syngas yield of 8.5 mmol/g, and CO yield of 4.2 mmol/g in CO2 decomposition. A-site defect engineering of the perovskite creates abundant oxygen vacancies and enhances oxygen storage capacity (OSC). Co-doping of the B-site of Sr0.98FeO3-δ increases oxygen mobility and CH4/CO2 activation, resulting in high activity in the CL-DRM process. This methodology resulted in high ionic mobility and facilitated the rapid diffusion of oxygen in the bulk phase, thereby increasing the redox properties of SrFeO3-δ. The oxygen carrier exhibits excellent structural stability and regeneration ability in successive redox cycles. This strategy offers a simple but very effective pathway to tailor OSC, oxygen mobility, and oxygen vacancies of perovskite-structured materials for chemical looping or redox-involved processes.

Synthesis of Nonsymmetric NBN-Embedded [6]- and [7]Helicenes with Amplified Activities.

Two C1-symmetric heterohelicenes were constructed by nonsymmetrically extending the ortho-fused structures of a C2v-symmetric NBN-embedded phenalene derivative and featured intense luminescence, large Stokes shifts, and successive reversible redox behaviors. Increasing one fused phenyl unit in such a helical structure led to a 10-fold-enhanced dissymmetry factor. Their strong double hydrogen-bond-donating capability makes them distinctly red-shifted in absorption, emission, and CD and CPL spectra upon the addition of fluoride anion.

Electronic effects of redox-active ligands on ruthenium-catalyzed water oxidation

The process of water oxidation presents a significant challenge in the development of artificial photosynthetic systems. This complexity arises from the necessity of charge accumulation, involving four electrons and four protons, and O–O bond formation. The strategy of using redox-active ligands in conjunction with metals is recognized as an effective approach for managing this charge accumulation process, attracting considerable attention. However, the detailed mechanisms by which the electronic effect of the redox-active ligands affect the reactivity of the catalytic centers remain ambiguous. In this study, the electronic effect of a series of mononuclear Ru complexes furnished with redox-active ligands ([(LRN5–)RuIII-OH]+, R = OMe, 3a; Me, 3b; H, 3c; F, 3d; CF3, 3e) was examined on water oxidation. A correlation was observed between redox potentials and substituent constants (σpara), indicating that different successive redox pairs are influenced by electron effects of varying intensities. Particularly, the ligand-centered oxidation (E {[(LN5–)+•RuIV=O]2+/[(LN5–)RuIV=O]+}) shows a greater dependence than the metal-centered PCET oxidations, E(RuIII-OH/RuII-OH2) and E(RuIV=O/RuIII-OH). The critical intermediate, [(LN5–)+•RuIV=O]2+, formed through ligand-centered oxidation, triggers O–O bond formation via its reaction with water. The rate constants of this crucial step can be effectively modulated by the substituents of the ligand. This study provides intricate insights into the role of the redox-active ligand in regulating the water oxidation process and further substantiates the effectiveness of the synergistic interaction of redox ligands and metals in controlling the multi-electron catalytic process.

Exploring the Impact of Successive Redox Events in Thin Films of Metal-Organic Frameworks: An Absorptiometric Approach.

Metal-organic frameworks (MOFs) featuring redox activity are highly appealing for electrocatalytic or charge accumulation applications. An important aspect in this field is the ability to address as many redox centers as possible in the material by an efficient diffusion of charges. Herein, we investigate for the first time the charge diffusion processes occurring upon two sequential one-electron reductions in an MOF thin film. Two pyrazolate-zinc(II)-based MOFs including highly electro-deficient perylene diimide (PDI) ligands were grown on conducting substrates, affording thin films with double n-type electrochromic properties as characterized by spectroelectrochemical analysis. In depth electrochemical and chronoabsorptiometric investigations were carried out to probe the charge diffusion in the MOF layers and highlighted significant differences in terms of diffusion kinetics and material stability between the first and second successive reduction of the redox-active PDI linkers. Our results show that MOFs based on multiredox centers are more sensitive to encumbrance-related issues than their monoredox analogues in the context of electrochemical applications, an observation that further underlines the fundamental aspect of careful pore dimensions toward efficient and fast ion diffusion.

A Medium‐Entropy Phosphate Cathode with Multielectron Redox Reaction for Advanced Sodium‐Ion Batteries

AbstractAchieving multi‐sodium storage and high operating voltage is key to boosting energy density of NASICON‐type materials. However, the activation of more redox couples is usually accompanied by asymmetric and irreversible electrochemical reactions, thus causing fast capacity fading. To address this issue, a medium‐entropy concept is proposed, and a novel medium‐entropy Na3Mn2/3V2/3Ti2/3(PO4)3/C@CNTs (ME‐NMVTP) cathode is designed. The as‐prepared ME‐NMVTP achieves a successive redox reaction, delivering a highly reversible specific capacity of 147.9 mA h g−1 at 50 mA g−1 together with a long‐term lifespan of 1000 cycles at 500 mA g−1 (capacity retention of 88.3%), which is superior to low‐entropy cathodes such as Na4MnV(PO4)3/C@CNTs (LE‐NMVP) and Na3MnTi(PO4)3/C@CNTs (LE‐NMTP). Moreover, benefiting from the entropy effect, solid‐solution and biphasic reactions with reversible structure evolution and small volume change are achieved during the multi‐sodium storage process. First‐principles calculation and kinetic analysis results affirm the enhanced electronic conductivity and facilitated Na+ migration of the ME‐NMVTP cathode derived from the synergistic effect of the three transition‐metal elementals in a medium‐entropy crystalline state. The strategy of engineering medium‐entropy to construct cathodes with superior performance is expected to be widely applicable to other electrode materials.

Unimolecular Chiral Stepping Inversion Machine.

Intelligent molecular machines that are driven by light, electricity, and temperature have attracted considerable interest in the fields of chemistry, materials, and biology. Herein, a unimolecular chiral stepping inversion molecular machine (SIMM) was constructed by a coupling reaction between dibromo pillar[5]arene and a tetrathiafulvalene (TTF) derivative (PT3 and PT5). Compared with the longer aliphatic linker PT5, PT3 with a shorter aliphatic linker shows chiral stepping inversion, achieving chiral inversion under a two-electron redox potential. Benefiting from the successive reversible two-electron redox potential of TTF, the self-exclusion and self-inclusion conformational transformations of SIMM can proceed in two steps under redox, leading to the chirality step inversion in the pillar[5]arene core. Electrochemical experiments and circular dichroism (CD) spectra show that the redox processes can cause SIMM CD signaling to reversibly switch. More importantly, as the oxidant Fe(ClO4)3 was increased from 0.1 to 1 equiv, the CD spectral signal of SIMM disappeared at 1 equiv, and further addition of Fe(ClO4)3 resulted in the CD signal reversed from positive to negative at 309 nm, indicating that the chirality was reversed after chemical oxidation and reached a negative maximum with the addition of 2 equiv Fe(ClO4)3; thus, redox-triggered chiral stepping inversion was achieved. Furthermore, the chiral inversion can be restored to its original state after the addition of 2 equiv of reducing agent, sodium ascorbate. This work demonstrates unimolecular chiral stepping inversion, providing a new perspective on stimulus-responsive chirality in molecular machines.

Highly active La0.35Sr0.35Ba0.3Fe1-xCoxO3 oxygen carriers with the anchored nanoparticles for chemical looping dry reforming of methane

Chemical looping dry reforming of methane (CL-DRM) has the potential as a viable technology to achieve carbon neutrality in terms of converting CH4 and CO2 to various value-added products with the minimal separation requirements. However, the design and development of an appropriate oxygen carrier (OC) with the remarkable reactivity and stability make the CL-DRM process challenging. Herein, the Co-substituted La0.35Sr0.35Ba0.3Fe1-xCoxO3 (LSBFC) perovskite oxides with the anchored nanoparticles as the novel OCs were synthesized and investigated for the redox performance in the CL-DRM process. It is found that the best substitution proportion of Co in the anchored perovskite oxides can be set in range of 0.2–0.6. The optimized OCs can greatly improve the reactivity of the chemical looping process based on various characterizations. Among all samples, La0.35Sr0.35Ba0.3Fe0.6Co0.4O3 OC increases the oxygen mobility and shows a higher oxygen diffusion rate to achieve the CH4 conversion of 84.3% and syngas yield of 15.23 mmol⋅g−1 in the CH4 reduction step, respectively. A detailed analysis of the anchored perovskite oxides reveals the substitution of Co can greatly weaken the perovskite lattice to result in the migration of Fe and the formation of Fe nanoparticles, which tremendously promote the activation of CH4 for the further conversion. Furthermore, the excellent OCs also exhibit the high stability in the enhanced reaction performance, the preservation of material structure and the stable regenerability by CO2 during the successive redox cycles. These features demonstrate that the new perovskite materials with anchored nanoparticles can be the promising oxygen carriers for the CL-DRM process.

Enhanced redox performance of LaFeO3 perovskite through in-situ exsolution of iridium nanoparticles for chemical looping steam methane reforming

Chemical looping steam methane reforming (CL-SMR) can produce high-purity hydrogen without additional separation units. However, the low reactivity of LaFeO3 oxygen carrier towards methane restricts the overall process performance. To enhance the redox activity of widely used LaFeO3 perovskite, a small amount of iridium was introduced to LaFeO3. The presence of iridium significantly enhanced both particle reduction and oxidation, and the particle preparation pathways of oxygen carriers greatly affected the long-term performance. The overall enhancement from the incorporation of iridium was demonstrated by density functional theory calculations. Despite these beneficial effects of iridium addition, surface iridium species prepared by an impregnation method were severely aggregated during successive redox cycling, leading to deactivation of the particles. In contrast, B-site incorporation of iridium leads to the exsolution of IrOx nanoparticles anchored on the perovskite host as well as to enhanced redox stability, which is essential for the long-term operation of the chemical looping process.

Tailoring Oxygen Vacancies and Active Surface Oxygen Species in Copper-Doped MnO2 Catalysts for Total Catalytic Oxidation of VOCs

Catalytic oxidation has been considered an essential route to tackle volatile organic compounds (VOCs)-driven pollution. To this point, surface engineering has emerged as a robust pathway to promote the efficiency of MnO2-based materials toward VOC oxidation. However, regulating such surface properties has been a critical challenge. This investigation attempts to tailor surface oxygen vacancies and active surface oxygen for the total catalytic oxidation of various VOCs (e.g., formaldehyde, isopropanol, and toluene) via doping copper into cryptomelane and birnessite-type MnO2 catalysts. The catalysts are synthesized by a novel facile successive redox precipitation method between KMnO4 and an ethanol solution containing copper nitrate precursors, followed by annealing. It turns out that the low amount of Cu dopants, corresponding to the copper-to-manganese ratio of 0.17 (RCu/Mn = 0.17), generates a tunnel-structured cryptomelane-type MnO2 with strong bulk oxygen mobility. Such a crystalline structure exhibits the best catalytic performance for the total catalytic oxidation of toluene. The higher copper loading (RCu/Mn = 0.27–0.34) drives the formation of Cu-doped layered birnessite-type MnO2 materials containing rich oxygen vacancies and high active surface oxygen species. Those catalysts promote the oxidation of isopropanol and formaldehyde, respectively. To this end, oxygen vacancies and surface oxygen species crucially steer the molecular oxygen activation and interactions toward adsorbed oxygen species, significantly promoting the total oxidation of isopropanol and formaldehyde, respectively. The explored finding could disclose an outstanding platform toward highly selective and efficient oxidation of VOCs.