Chlorobenzene Research Articles

Catalytic degradation of chlorinated volatile organic compounds (CVOCs) over Ce-Mn-Ti composite oxide catalysts

Developing industrially moldable catalysts with harmonized redox performance and acidity is of great significance for the efficient disposal of chlorinated volatile organic compounds (CVOCs) in actual exhaust gasses. Here, commercial TiO2, typically used for molding catalysts, was chosen as the carrier to fabricate a series of Ce0.02Mn0–0.24TiOx materials with different Mn doping ratios and employed for chlorobenzene (CB) destruction. The introduction of Mn remarkedly facilitated the synergistic effect of each element via the electron transfer processes: Ce3++Mn4+/3+↔Ce4++Mn3+/2+ and Mn4+/3++Ti4+↔Mn3+/2++Ti3+. These synergistic interactions in Ce0.02Mn0.04–0.24TiOx, especially Ce0.02Mn0.16TiOx, significantly elevated the active oxygen species, oxygen vacancies and redox properties, endowing the superior catalytic oxidation of CB. When the Mn doping amount increased to 0.24, a separate Mn3O4 phase appeared, which in turn might weaken the synergistic effect. Furthermore, the acidity of Ce0.02Mn0.04–0.24TiOx was decreased with the Mn doping, regulating the balance of redox property and acidity. Notably, Ce0.02Mn0.16TiOx featured relatively abundant B-acid sites. Its coordinating redox ability and moderate acidity promoted the deep oxidation of CB and RCOOH- intermediates, as well as the rapid desorption of Cl species, thus obtaining sustainable reactivity. In comparison, CeTiOx owned the strongest acidity, however, its poor redox property was not sufficient for the timely oxidative decomposition of the easier adsorbed CB, resulting in its rapid deactivation. This finding provides a promising strategy for the construction of efficient commercial molding catalysts to decompose the industrial-scale CVOCs.

Characterization of physicochemical properties of activated carbons prepared from penicillin mycelial residues and its adsorption properties for VOCs

In this study, adhering to the concept of "treat waste with waste", the physicochemical properties of activated carbons (ACs) prepared from penicillin mycelial residues (PMR) was characterized, and the adsorption performance of ACs for VOCs was explored. The results showed that AC230–1 exhibited the largest specific surface area (2187.50 m2/g), while AC290–0.5 exhibited the largest microporous surface area (1624.81 m2/g). With the increase of KOH ratio, microporous surface area of ACs decreased gradually, and the pore size distribution of ACs gradually developed to large micropores and mesopores. XRD and Raman results showed that AC290–0.5 had better graphite microcrystalline structure and stability. FT-IR results showed that ACs had similar surface functional groups, and XPS results indicated that AC290–0.5 contained more CO, C-OH, and abundant N-containing functional groups, which could effectively improve the adsorption capacity of ACs for VOCs. AC290–0.5 exhibited the highest dichloromethane (DCM) saturation adsorption capacity (204.83 mg/g), trichloroethylene (TCE) saturation adsorption capacity (732.59 mg/g) and chlorobenzene (CLB) saturation adsorption capacity (735.90 mg/g). The Y–N model could perfectly fit the adsorption breakthrough curve of ACs for VOCs, and adsorption kinetics indicated that the adsorption of ACs for VOCs was mainly physical adsorption. The microporous and surface chemical group of AC were the main factors that determined its adsorption capacity for VOCs.

Highly active and durable chlorobenzene oxidation catalyst via porous atomic layer coating of Ru on Pt/Al2O3

Herein, we designed and fabricated a novel subnanometer Ru-coating Pt/Al2O3 catalyst (named RuPt-ALD) via atomic layer deposition (ALD), which showed an excellent capability of tuning catalysts’ structure-property relationship for chlorobenzene (CB) oxidation. Subnanometer Ru clusters were separately decorated onto Pt nanoparticles, while leaving neighboring Pt surfaces exposed, which could effectively enhance the substrate-particles interaction by electron donation. RuPt-ALD provided optimal activity and selectivity, and a stable CB conversion of ∼98 % for 600 min at 200 °C in humid air, superior to bare Ru or Pt samples. Experimental verification and theoretical calculation identified that the relative lower barriers of CB adsorption and O2 dissociation on RuPt-ALD contributed to its stronger CB adsorption and appropriate oxygen activation capacity, which were the core factors for the excellent performance under humid feed. In addition, under dry feed, the desorption ability of Cl species was also a key factor affecting the performance of Pt-based catalysts.

Oriented Organization of Poly(3‐Hexylthiophene) for Efficient and Stable Antimony Sulfide Solar Cells

Poly(3‐hexylthiophene) (P3HT), as a traditional organic hole‐transporting material (HTM), is widely used in thin‐film solar cells due to its high charge mobility and good thermal stability. However, the P3HT films obtained by the traditional method are amorphous, which is unfavorable to hole extraction and transport. Here, a low‐toxicity solvent 1,2,4‐trimethylbenzene (TMB) was used as the solvent instead of the commonly used halogen solvent chlorobenzene (CB) to dissolve P3HT. Thus, the self‐assembled nanofibrous P3HT film was prepared and applied as HTM in the newly emerged Sb2S3 solar cells. According to the density functional theory calculations, the interface contact between TMB‐P3HT and Sb2S3 was enhanced via the bonding interaction of S in P3HT and Sb in Sb2S3. Through transient absorption spectroscopy characterization, the enhanced interface contact improves the charge extraction ability of TMB‐P3HT when compared to the CB‐P3HT film. Thus, the TMB‐P3HT‐based Sb2S3 solar cell delivers a power conversion efficiency of 6.21%, which is 9.7% higher than that of the CB‐P3HT‐based device. Furthermore, the dopant‐free TMB‐P3HT‐based Sb2S3 devices exhibit excellent environmental stability compared with Spiro‐OMeTAD‐based devices. This work demonstrates that the application of P3HT and the solvent engineering of HTM are applicable strategies for developing Sb2S3 solar cells with high efficiency and stability.

Ultrafast One-Step Deposition Route to Fabricate Single-Crystal CsPbX3 (X = Cl, Cl/Br, Br, and Br/I) Photodetectors.

Inorganic perovskites have received much attention due to their stability and high performance in luminescence, photoelectric conversion, and photodetection. However, perovskite optoelectronic devices prepared by the solution technique are still suffering from time-consuming and complex operations. In this paper, a single-crystal perovskite-based photodetector (PD) is prepared by very fast one-step deposition of synthesizing microplatelets (MPs) on the electrode directly. The saturated precursor is carefully optimized by adding appropriate antisolvent chlorobenzene (CB) to fabricate the MPs with their PL wavelength ranging from 418 to 600 nm. Furthermore, the PDs with a low dark current on order of nanoangstroms, high responsivity and detectivity of up to 10.7 A W-1 and 1012 Jones, respectively, and an ultrafast response rate featured by 278/287 μs (rise/decay time) are achieved. These all-inorganic perovskite PDs with a simple fabricating process and tunable detection wavelength meet the evolution tendency of PDs toward low cost and high performance, which is a high-profile strategy to realize high-performance perovskite PDs.

Oxygen-mediated dielectric barrier discharge plasma for enhanced degradation of chlorinated aromatic compounds

Chlorinated aromatic compounds (CACs), a kind of refractory pollutants, pose a potential risk to the environment and human health. Herein, dielectric barrier discharge (DBD) plasma is employed to enhance the degradation of 2,4-dichlorophenol (2,4-DCP) from water, and O2 is the most efficient working atmosphere with totally 2,4-DCP degradation in 40 min. O3, ·OH, ·O2– and 1O2 are the main active species responsible for the degradation, while the contribution of hydrated electrons and reactive nitrogen species is almost negligible. Moreover, highly efficient o-Nitrochlorobenzene (o-NCB) and chlorobenzene (CB) degradation and mineralization are also achieved in DBD/O2 process. All the CACs are completely degraded in 60 min following the degradation rate order of CB > 2,4-DCP > o-NCB, which almost follows the order of ionization potential values. The mineralization efficiencies of CB, 2,4-DCP and o-NCB reach 61.14 %, 70.50 % and 92.77 % in DBD/O2 process, respectively, which are 1.74,1.15 and 1.28 times higher than that in DBD process alone. Based on theoretical calculation and intermediates analysis, three common degradation pathways are proposed including hydroxylation, dechlorination and ring-opening. Soil remediation experiments further indicate the high efficiency and promising perspective of DBD/O2 process in CACs contaminated soil treatment. This work is instructive to elucidate the importance of O2 atmosphere in the degradation of CACs by DBD plasma system and provides an alternative way for removing CACs from water and soil.

Degradation of chlorobenzene by non-thermal plasma coupled with catalyst: influence of catalyst, interaction between plasma and catalyst

Non-thermal plasma (NTP) is considered to be a promising technology for the removal of volatile organic compounds; however, its application is limited by low CO2 selectivity and undesirable by-products. To overcome these issues, this paper discusses the degradation of chlorobenzene (CB) in systems of NTP coupled with catalysts, and the influence of catalyst locations in the NTP was investigated. In addition, the interaction between plasma and catalyst was also explored. The results indicated that the degradability of CB was remarkably improved through the combination of NTP with catalysts, and the formation of ozone was effectively inhibited. The degradation efficiency increased from 33.9% to 79.6% at 14 kV in the NTP-catalytic system, while the ozone concentration decreased from 437 to 237 mg m−3, and the degradation efficiency of in plasma catalysis (IPC) systems was superior to that of the post plasma catalysis system, while the inhibition ability of ozone exhibited an opposing trend. In the IPC system, the degradation efficiency was 87.7% at 14 kV, while the ozone concentration was 151 mg m−3. Besides, the plasma did not destroy the pore structure and crystal structure of the catalyst, but affected the surface morphology and redox performance of the catalyst. Thus, NTP coupled catalytic system could improve the degradation performance of CB. Furthermore, the plasma discharge characteristics played a major role in the NTP synergistic catalytic degradation of CB. Finally, based on the experiment analysis results, the general reaction mechanism of CB degradation in an IPC reaction system was proposed.

High Efficiency Near-Infrared Perovskite Light Emitting Diodes With Reduced Rolling-Off by Surface Post-Treatment.

The rolling-off phenomenon of device efficiency at high current density caused by quenching of luminescence in perovskite light-emitting diodes (PeLED) is challenging to be solved. Here, 2-amino-5-iodopyrazine (AIPZ) is dissolved in a mixed solvent of chlorobenzene (CB)/isopropanol (IPA) (7:3 volume ratio) for surface post-treatment of FAPbI3 perovskite film. The interaction of AIPZ and perovskite surface not only balances the charge injection but also passivates defects to enhance radiative recombination in PeLED. Therefore, the PeLED champion yields peak external quantum efficiency reaching 23.2% at the current density of 45mA cm-2 with a radiance brightness of 290W sr-1 m-2 . More importantly, the rolling-off of device efficiency is significantly reduced. The lowest rolling-off devices can maintain 80% of peak EQE (22.1%) at a high current density of 460mA cm-2 , whereas the control device only retains 25% of the peak EQE value. This work provides an effective strategy to improve performance and reduce the EQE rolling-off of PeLED for practical application.

Enhancing the performance of perovskite solar cell via optimizing the solvent of hole transport layer

Poly(9-vinylcarbazole) (PVK) is an attractive hole transport layer (HTL) for high efficiency perovskite solar cells (PSCs). But there is still some room for improvement in energy level alignment between the highest occupied molecular orbital (HOMO) of PVK and the perovskite layer. In this work, the solvent of PVK-based HTL was optimized to adjust the energy level of HTLs by changing the volume ratio of chlorobenzene (CB) in dimethylformamide (DMF). Experimental results shows that 20% is the optimal ratio of CB in DMF, based on which the HOMO level of HTL was lifted from −5.62 eV to −5.44 eV. Meanwhile, the morphology of perovskite layer with larger grain size and lower trap density was obtained. As a result, the V OC and J SC of PSCs was enhanced, leading to the increase of PCE from 15.41% to 18.27%. This work paves the way to realize high-efficiency PSCs based on PVK HTL. • The solvent of PVK-based HTL was optimized to adjust the energy level of HTLs. • The HOMO level of HTL was lifted from −5.62 eV to −5.44 eV. • The V OC and J SC of PSCs was enhanced, leading to the increase of PCE from 15.41% to 18.27%.

In Situ Study the Dynamics of Blade‐Coated All‐Polymer Bulk Heterojunction Formation and Impact on Photovoltaic Performance of Solar Cells

All‐polymer solar cells (all‐PSCs) have achieved impressive progress by employing acceptors polymerized from well performing small‐molecule non‐fullerene acceptors. Herein, the device performance and morphology evolution in blade‐coated all‐PSCs based on PBDBT:PF5–Y5 blends prepared from two different solvents, chlorobenzene (CB), and ortho‐xylene (o‐XY) are studied. The absorption spectra in CB solution indicate more ordered conformation for PF5–Y5. The drying process of PBDBT:PF5–Y5 blends is monitored by in situ multifunctional spectroscopy and the final film morphology is characterized with ex situ techniques. Finer‐mixed donor/acceptor nanostructures are obtained in CB‐cast film than that in o‐XY‐cast ones, corresponding to more efficient charge generation in the solar cells. More importantly, the conformation of polymers in solution determines the overall film morphology and the device performance. The relatively more ordered structure in CB‐cast films is beneficial for charge transport and reduced non‐radiative energy loss. Therefore, to achieve high‐performance all‐PSCs with small energy loss, it is crucial to gain favorable aggregation in the initial stage in solution.

Structural Characteristics and Functional Genes of Biofilms in Microbial Electrolysis Cells for Chlorobenzene Abatement

Chlorobenzene (CB) is typically emitted during industry and waste incineration, posing hazards to the safety of humans and the ecosystem. Successful CB elimination has been achieved in microbial electrolysis cells (MECs), whereas little is known about elimination effectiveness in response to the structural and functional characteristics of biofilms. Herein, the bacterial viability and functional gene abundance of biofilms in MECs with carbon cloth (CC), reticulated vitreous carbon (RVC), and nickel foam (NF) as cathodes are emphasized. Experimental results reveal that bacterial viability on RVC is 62 and 92% higher than that of CC and NF, respectively, achieving 30 and 65% superior CB removal efficiency. Notably, the MEC with RVC outperforms that with the highly conductive NF due to low electron loss, causing a twice as much increase in coulombic efficiency. Metagenomic analysis indicates that the CB degrader (i.e., Pandoraea), electrochemically active bacteria (i.e., Chryseobacterium), and genes responsible for CB metabolism (i.e., todD and clcB) in RVC biofilms increase by over 30%, fourfold, and 10%, respectively, compared to CC and NF. Moreover, CB degradation is found to occur via two possible pathways: (1) thorough elimination by dechlorination, hydrolysis, and oxidation after conversion to 3-chlorocatechol, and (2) conversion into phenol and benzoate for complete degradation.

Antisolvent-Treated MAPbI3 and PbS Quantum Dots for High-Performance Broadband Photodetectors

Nowadays, halide perovskites have drawn extensive attention as active layers in the field of photodetectors (PDs) attributed to their optoelectric properties. However, the numerous defects in the prepared films and the lack of response in the near-infrared (NIR) range due to the intrinsic band gap limitation severely restrict the performances and applications of perovskite photodetectors. With this in mind, we introduced diethyl ether as a counter-solvent to improve the quality of the peroxide films. After comparison with chlorobenzene (CB), toluene (ToL), and ethyl acetate (EA), the mechanism by which diethyl ether (DE) as an antisolvent improves the quality of the films was explored. MAPbI3 films and lead sulfide (PbS) quantum dots (QDs) were then combined to achieve a visible (VIS)–near-infrared response. The resultant PD, with the structure of ITO/NiOx/PbS QDs/MAPbI3/PC61BM/Ag, exhibits an ultrabroad response from 300 to 1100 nm and presents high detectivity reaching 5.6 × 1011 and 6.5 × 1010 Jones in the VIS and NIR regions, respectively. The fast response time in the microsecond range and the response bandwidth of 10 kHz (f–3 dB) are comparable or even superior to counterparts. In addition, this approach provides ideas for the development of high-performance broadband perovskite-based optoelectronic devices.

Versatile Processability by Breaking the Symmetrical Chemical Structure of Nonfullerene Acceptors

Despite the outstanding photovoltaic performance of symmetrical Y6, its use is limited in that only chloroform (CF), a highly volatile processing solvent, can induce favorable morphology. This dependence on a particular solvent poses an obstacle to mass production. Here, we investigate the effect of symmetry‐breaking of nonfullerene acceptors (NFAs) on device performance and processability by employing chlorobenzene (CB) or CF processing solvents. In organic solar cells (OSCs) based on a symmetrical Y6 acceptor, a significant difference in the power conversion efficiency occurs between the OSCs fabricated using CB and those fabricated using CF. However, in OSCs based on IPC‐BEH‐IC2F with asymmetrical structure, no difference in photovoltaic performance occurs between the two OSCs. Grazing‐incidence wide‐angle X‐ray scattering measurements indicate that IPC‐BEH‐IC2F exhibits nearly identical diffraction features in both the CB‐ and CF‐processed photoactive films, whereas Y6 shows markedly different stacking structures. Because of these morphological features, OSCs based on Y6 are associated with a relatively large energy loss difference in CB and CF, whereas OSCs based on IPC‐BEH‐IC2F show no significant difference in energy loss. The introduction of an asymmetrical structure can therefore be an important strategy to enhance the versatile processability of OSCs based on NFAs for future mass production.

Deciphering the role of antisolvent on the structural and optical properties of CH3NH3PbI3 film and its impacts on the performance and stability of n-i-p perovskite solar cells

This study presents an in-depth morphological, structural, and optical study of CH3NH3PbI3 (MAPbI3) film during the antisolvent dripping time, and their relevance to the stability and performance of perovskite solar cells (PSCs) is revealed. The detrimental role of the antisolvent is best demonstrated by using chlorobenzene (CB) as an antisolvent and comparing PSC devices fabricated from CB-free versus PSCs containing CB at different dripping times (5, 10, 15, 20, and 25 s) before the end of deposition of CH3NH3PbI3 film (deposition time was 30 s). Scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), UV–Vis absorption spectroscopy, Urbach energy analysis, steady-state photoluminescence (PL) spectra, current-voltage (I–V), external quantum efficiency (EQE), and water droplet contact angle measurement techniques were utilized to evaluate the characteristics of obtained MAPbI3 films, photovoltaic parameters, and the stability of constructed n-i-p PSCs. It was observed that changing the antisolvent dripping time changes the optical and structural properties of the MAPbI3 layer, including the direct and indirect optical band gap, refractive index, extinction coefficient, dielectric constant, optical conductivity, Urbach energy, dislocation density, lattice strain, crystallite size, and lattice parameters. The above-mentioned parameters were investigated in detail. Accordingly, by dripping the CB at 20 s before the end of the deposition process (labeled as a sample of 20 s), the created MAPbI3 layer had a smoother and pinhole-free surface, resulting in higher crystallinity than the other samples. The values of the direct band gap of the created MAPbI3 films varied from 1.51 to 1.61 eV, corresponding to samples CB-free and 20 s, respectively. For all samples, the indirect band gap was 60 meV lower than the direct band gap. Also, the sample at 20 s had a lower Urbach energy, indicating that this sample's interband defects are less than other models. In addition, the PSCs with CB-dripping at 20 s exhibited higher power conversion efficiency (13.95%) and outstanding stability of power output (<16% decay) as compared to the device without CB-dripping (>82% decay) after keeping in ambient air for about 1450 h at 40 ± 10% RH and 25 ± 5 °C. This systematic comparative study of the structural and optical properties of the perovskite layer can provide a promising platform for achieving high-quality perovskite films to overcome the shortcomings of instability and degradation.

Formation of PCDD/Fs, PCBs and HCl during catalytic combustion of chlorobenzene over supported transition metal (Cr, V and Cu) oxide catalysts

As an efficient scheme, catalytic combustion can be used to eliminate chlorinated volatile organic compounds (CVOCs). To avoid the formation of more toxic by-products, it is essential to reveal the relationship between the chlorine-containing products and redox properties of catalyst. In the present study, the activity for chlorobenzene (CB) oxidation, HCl production, and formation of by-products polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs)were investigated over γ-Al2O3-supported transition metal (Cr, V and Cu) oxide catalysts. The results showed that the 10Cr-Al catalyst with relatively high specific surface areaand more oxygen absorbed than other catalysts exhibited higher catalytic oxidation activity for CB. The temperatures needed for 90% conversion of CB (T90) were 331, 353 and 386 °C for 10Cr-Al, 10V-Al and 10Cu-Al, respectively. The amount and type of acid sites on the surface of catalysts play an important role in the distribution of products and by-products. It was found that the increase of acid sites and the presence of Brønsted acid (B-acid) significantly improve the HCl selectivity of catalysts. More HCl was formed on the 10V-Al catalyst with B-acid sites. Meanwhile PCDD/Fs and PCBs detected in the by-products had a tight relationship with the acidity sites and redox performance of the catalyst. The yields of ∑PCDD/Fs and ∑PCBs were the largest on 10V-Al at T10, reaching 25.60, 66.93 mmol/mol CB, respectively. The obtained results provided theoretical support for the subsequent development of CVOCs catalytic oxidation catalysts and the control of toxic by-products.

Surface treatment of PTAA hole transport layer for inverted perovskite solar cells

Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) was chosen as a hole transport layer for inverted perovskite solar cells (PSCs). It is the first layer deposited on the FTO substrate and thus directly affect the structure and performance of the PSCs. It was found that untreated PTAA surfaces yielded large distribution of photovoltaic parameters and low reproducibility. In this work, the PTAA powder was dissolved in chlorobenzene (CB) and spin-coated on the FTO substrates and baked at 105 °C for 10 mins as pristine samples. The surface treatment of PTAA was performed by washing the pristine samples with 200 µl dimethyl formamide (DMF) on a spin coater and followed by dynamic spin of 50-75 µl of CB or Toluene (TO). It was observed that the surface treatment affected the wettability of PTAA surface by the reduction of contact angle from 46° of pristine sample to 25° – 35° of treated samples that could lead to a better interface and formation of a MAPbI3 perovskite layer. On the contrary, the optical transmittance and surface morphology the treated samples were insignificantly affected. It was demonstrated that the surface treatment of PTAA using DMF and 50 µl of TO could significantly reduce the fluctuation of photovoltaic parameters and also improve the repeatability of the fabrication process. The maximum power conversion efficiency (PCE) of 15.4% was obtained for the optimal condition.

Green-Solvent Engineering for Depositing Qualified Phenyl-C61-butyl Acid Methyl Ester Films for Inverted Flexible Perovskite Solar Cells.

Flexible perovskite solar cells (fPSCs) with the inverted structure (p-i-n structure) show a promising commercialization future, owing to their lightweight and high efficiencies. Phenyl-C61-butyric-acid methyl ester (PCBM) is widely used as the n-type material due to its excellent conductivity and solvent processability. However, the commonly used chlorobenzene (CB), as the solvent of PCBM solution, is well recognized as a halogenated contaminant in the environment and is harmful to human health. There is an imperative need to develop nonhalogenated green solvents to replace CB. This work discusses the selection of green solvents based on the Hansen solubility parameters (HSPs). It is found that 2-methylanisole (2-MEA) acts as an excellent alternative to CB, with which high-quality PCBM films could be deposited. The experimental and theoretical studies demonstrate that 2-MEA can suppress the formation of PCBM aggregations during the solvation process compared with CB. The more uniform PCBM film achieved from the 2-MEA solution benefits carrier extraction at the electronic transport layer (ETL)/perovskite interface. As a result, better efficiencies are received among fPSCs based on the 2-MEA-processed PCBM, superior to that of the fPSCs based on the CB-processed PCBM. Moreover, using 1,8-diiodooctane (DIO) as a solvent additive is proven to further increase the solubility of PCBM in the 2-MEA solution, resulting in enhanced efficiencies of the flexible PSCs by more than 5% (from 19.25 to 20.30%). The developed green-solvent strategy is of great importance for the future large-scale production of environmentally sustainable fPSCs.

Improved activity and stability for chlorobenzene oxidation over ternary Cu-Mn-O-Ce solid solution supported on cordierite.

A series of CuMnOx/CeO2/cordierite and CuMnCeOx/cordierite catalysts prepared by a complex method with citric acid were investigated for the performance of chlorobenzene (CB) oxidation. The effects of the molar ratio of Mn/Cu, transition metal oxide loading, calcination temperature and time were investigated as the main investigation factor for the performance. Meanwhile, XRD, SEM, BET, H2-TPR, O2-TPD and XPS were conducted to characterize the physicochemical properties of these catalysts. The results demonstrated that CuMnOx/CeO2/cordierite catalysts prepared by step-by-step synthesis with the Cu/Mn molar ratio of 5:2 exhibited a high activity (T90 = 350°C), owing to the incorporation of CuO and MnOx for forming CuMn2O4 spinel oxide supported on CeO2 surface. More importantly, CuMnCeOx/cordierite catalysts prepared by one-step exhibited the highest oxidation activity (T90 < 300°C) attributed to the low H2 reduction temperature and desorption energy of surface oxygen, and the formed Cu-Mn-O-Ce solid solution and CeO2 promoted the high dispersion of CuMnOx in the supported catalysts. In addition, the possible oxidation mechanism was described to demonstrate the by-products generation and oxygen transfer of CuMnCeOx catalysts.

D 6 h Symmetric Radical Donor–Acceptor Nanographene Modulated Interfacial Carrier Transfer for High-Performance Perovskite Solar Cells

<i>D</i> ^{6 <i>h</i>} Symmetric Radical Donor–Acceptor Nanographene Modulated Interfacial Carrier Transfer for High-Performance Perovskite Solar Cells

Removing Chlorobenzene via the Synergistic Effects of Adsorption and Catalytic Oxidation over Activated Carbon Fiber Loaded with Transition Metal Oxides

This study focused on the elimination of chlorobenzene by dual adsorption/catalytic oxidation over activated carbon fibers (ACFs) loaded with transition metal oxides (TMOs). The TMOs were successfully loaded on the ACFs by the incipient wetness impregnation method, which has the advantages of easy preparation, low cost, and size uniformity. The removal effects for chlorobenzene (CB) were investigated on pristine ACFs and TMOs@ACFs in a fix-bed reactor. The adsorption/catalytic oxidation experiments result demonstrated that ACFs can be used as a very efficient adsorbent for the removal of low-concentration CB at the low temperature of 120 °C; the breakthrough time of CB over pristine ACFs can reach 15 h at an inlet concentration of 5000 ppmv and space velocity of 20,000 h−1. As the bed temperature rose above 175 °C, the CB removal mainly contributed to the catalytic oxidation of MnO2; a preferable CB removal ratio was achieved at higher temperatures in the presence of more MnO2. Therefore, CB can be effectively removed by the dual adsorbent/catalyst of MnO2@ACF at the full temperature range below 300 °C.