In Situ Photodeposition of Gold Nanoparticles with Exposed High-Activity Crystal Facets under Different Sacrificial Agents.

In situ photodeposition presents a powerful approach for integrating noble metal co-catalysts onto semiconductor surfaces. However, achieving precise control over the microstructure of the deposited co-catalyst remains a major challenge. Au nanoparticles (NPs) are deposited onto H-KCNO using HAuCl4 in the presence of various sacrificial agents in this study. Notably, the choice of sacrificial agent decisively influences the exposed crystal facets, loaded content, and particle size of the deposited Au NPs. Importantly, in situ photodeposition under an ethanol solution facilitates the exposure of the highly active (111) and (220) crystal facets of Au. The introduction of Au NPs significantly enhances photocatalytic hydrogen evolution, achieving rates of 4.93, 57.88, and 15.44 µmol/h for H-KCNO/Au-(water, ethanol, and lactic acid), respectively. The observed photocatalytic activity for hydrogen evolution indicates that the exposure of the highly active planes emerges as critical for significant performance enhancement. Photoelectrochemical and photoluminescence measurements suggest that the highly active (111) and (220) crystal facets effectively segregate sites for redox reactions, thereby impeding the recombination of photogenerated electron-hole pairs.

Improving benzene catalytic oxidation on Ag/Co3O4 by regulating the chemical states of Co and Ag.

Silver (9 wt.%) was loaded on Co3O4-nanofiber using reduction and impregnation methods, respectively. Due to the stronger electronegativity of silver, the ratios of surface Co3+/Co2+ on Ag/Co3O4 were higher than on Co3O4, which further led to more adsorbed oxygen species as a result of the charge compensation. Moreover, the introducing of silver also obviously improved the reducibility of Co3O4. Hence the Ag/Co3O4 showed better catalytic performance than Co3O4 in benzene oxidation. Compared with the Ag/Co3O4 synthesized via impregnation method, the one prepared using reduction method (named as AgCo-R) exhibited higher contents of surface Co3+ and adsorbed oxygen species, stronger reducibility, as well as more active surface lattice oxygen species. Consequently, AgCo-R showed lowest T90 value of 183°C, admirable catalytic stability, largest normalized reaction rate of 1.36 × 10-4 mol/(h·m2) (150°C), and lowest apparent activation energy (Ea) of 63.2 kJ/mol. The analyzing of in-situ DRIFTS indicated benzene molecules were successively oxidized to phenol, o-benzoquinone, small molecular intermediates, and finally to CO2 and water on the surface of AgCo-R. At last, potential reaction pathways including five detailed steps were proposed.

Unlock the Visible-Light Photocatalytic OWS by Surface Disorder-Engineered Bi-Based Composite Oxides through Phosphorization.

It has been proven that the introduction of disorder in the surface layers can narrow the energy band gap of semiconductors. Disordering the surface's atomic arrangement is primarily achieved through hydrogenation reduction. In this work, we propose a new approach to achieve visible-light absorption through surface phosphorization, simultaneously raising the energy band structure. In particular, the surface phosphorization of BixY1-xVO4 was successfully prepared by annealing them with a small amount of NaH2PO2 under a N2 atmosphere. After this treatment, the obtained BixY1-xVO4 showed distinct absorption in visible light. The surface phosphorization treatment not only improves the photocatalytic activity of BixY1-xVO4 but also enables visible-light photocatalytic overall water splitting. Furthermore, we demonstrate that this surface phosphorization method is universal for Bi-based composite oxides.

Proteomic sequencing analysis in a rat model of atrial fibrosis caused by chronic intermittent hypoxia.

Background: Atrial fibrosis caused by long-term atrial fibrillation influences the outcomes of clinical treatment. An improved understanding of the mechanisms underlying atrial fibrillation may reveal new therapeutic targets. This study was conducted to analyze the changes in protein levels in the atrial tissue of a rat model of atrial fibrillation based on proteome sequencing. Methods: Sprague-Dawley rats were used to develop a model of atrial fibrillation induced by chronic intermittent hypoxia (CIH). Histopathological changes were detected using hematoxylin and eosin staining and Masson's staining, and immunohistochemistry and western blotting for the levels of fibrosis biomarkers. Atrial fibrosis tissue samples were also evaluated by proteome sequencing. Differentially expressed proteins (DEPs) between the CIH and control groups were evaluated in functional assay. The expression levels of several key proteins were validated using western blotting. Results: CIH resulted in atrial fibrosis and induced atrial fibrillation. We identified 145 DEPs between the CIH and control groups. These included Myh7, Myl2, Myl3, and Atpla3, which are involved in signaling pathways related to hypertrophic cardiomyopathy, glycerolipid metabolism, and cardiac muscle contraction. Western blotting revealed the upregulation of Myh7, Myl2, and Myl3 and the downregulation of Atpla3 in the CIH group compared with the control group. These results were consistent with the sequencing results. Conclusions: Myh7, Myl2, Myl3, and Atpla3 may play key roles in the progression of atrial fibrillation through their involvement in cardiovascular-disease-related signaling pathways.

Cfa-circ002203 was upregulated in rapidly paced atria of dogs and involved in the mechanisms of atrial fibrosis.

Background and aims: The role of circular RNAs (circRNAs) in the pathophysiology of cardiovascular disease is gradually being elucidated; however, their roles in atrial fibrillation (AF)-related fibrosis are largely unknown. This study aimed to characterize the different circRNA profiles in the rapid-pacing atria of dogs and explore the mechanisms involved in atrial fibrosis. Methods: A rapid right atrial-pacing model was established using electrical stimulation from a pacemaker. After 14 days, atrial tissue was collected for circRNA sequencing analysis. In vitro fibrosis was established by stimulating canine atrial fibroblasts with angiotensin II (Ang II). The fibroblasts were transfected with siRNA and overexpressing plasmids to explore the effects of cfa-circ002203 on fibroblast proliferation, migration, differentiation, and the expression of fibrosis-related proteins. Results: In total, 146 differentially expressed circRNAs were screened, of which 106 were upregulated and 40 were downregulated. qRT-PCR analysis showed that cfa-circ002203 was upregulated in both in vivo and in vitro fibroblast fibrosis models. The upregulation of cfa-circ002203 enhanced proliferation and migration while weakening the apoptosis of fibroblasts. Western blotting showed that cfa-circ002203 overexpression increased the protein expression levels of fibrosis-related indicators (Col I, Col III, MMP2, MMP9, and α-SMA) and decreased the protein expression levels of pro-apoptotic factors (Bax and Caspase 3) in Ang II-induced fibroblast fibrosis. Conclusion: Cfa-circ002203 might serve as an active promoter of the proliferation, migration, and fibrosis of atrial fibroblasts and is involved in AF-induced fibroblast fibrosis.

Catalytic degradation of benzene over non-thermal plasma coupled Co-Ni binary metal oxide nanosheet catalysts.

Non-thermal plasma (NTP) has been demonstrated as one of the promising technologies that can degrade volatile organic compounds (VOCs) under ambient condition. However, one of the key challenges of VOCs degradation in NTP is its relatively low mineralization rate, which needs to be addressed by introducing catalysts. Therefore, the design and optimization of catalysts have become the focus of NTP coupling catalysis research. In this work, a series of two-dimensional nanosheet Co-Ni metal oxides were synthesized by microwave method and investigated for the catalytic oxidation of benzene in an NTP-catalysis coupling system. Among them, Co2Ni1Ox achieves 60% carbon dioxide (CO2) selectivity (SCO2) when the benzene removal efficiency (REbenzene) reaches more than 99%, which is a significant enhancement compared with the CO2 selectivity obtained without any catalysts (38%) under the same input power. More intriguingly, this SCO2 is also significantly higher than that of single metal oxides, NiO or Co3O4, which is only around 40%. Such improved performance of this binary metal oxide catalyst is uniquely attributed to the synergistic effects of Co and Ni in Co2Ni1Ox catalyst. The introduction of Co2Ni1Ox was found to promote the generation of acrolein significantly, one of the key intermediates found in NTP alone system reported previously, suggest the benzene ring open reaction is promoted. Compared with monometallic oxides NiO and Co3O4, Co2Ni1Ox also shows higher active oxygen proportion, better oxygen mobility, and stronger low-temperature redox capability. The above factors result in the improved catalytic performance of Co2Ni1Ox in the NTP coupling removal of benzene.

Integrated whole transcriptome analysis for the crucial regulators and functional pathways related to cardiac fibrosis in rats.

BACKGROUND: Cardiac fibrosis has gradually gained significance in the field of cardiovascular disease; however, its specific pathogenesis remains unclear. This study aims to establish the regulatory networks based on whole-transcriptome RNA sequencing analyses and reveal the underlying mechanisms of cardiac fibrosis. METHODS: An experimental model of myocardial fibrosis was induced using the chronic intermittent hypoxia (CIH) method. Expression profiles of long non-coding RNA (lncRNA), microRNA (miRNA), and messenger RNA (mRNA) were acquired from right atrial tissue samples of rats. Differentially expressed RNAs (DERs) were identified, and functional enrichment analysis was performed. Moreover, a protein-protein interaction (PPI) network and competitive endogenous RNA (ceRNA) regulatory network that are related to cardiac fibrosis were constructed, and the relevant regulatory factors and functional pathways were identified. Finally, the crucial regulators were validated using qRT-PCR. RESULTS: DERs, including 268 lncRNAs, 20 miRNAs, and 436 mRNAs, were screened. Further, 18 relevant biological processes, such as "chromosome segregation, " and 6 KEGG signaling pathways, such as "cell cycle, " were significantly enriched. The regulatory relationship of miRNA-mRNA-KEGG pathways showed eight overlapping disease pathways, including "pathways in cancer." In addition, crucial regulatory factors, such as Arnt2, WNT2B, GNG7, LOC100909750, Cyp1a1, E2F1, BIRC5, and LPAR4, were identified and verified to be closely related to cardiac fibrosis. CONCLUSION: This study identified the crucial regulators and related functional pathways in cardiac fibrosis by integrating the whole transcriptome analysis in rats, which might provide novel insights into the pathogenesis of cardiac fibrosis.

Effects of radiofrequency balloon angioplasty on the abdominal aorta in atherosclerotic rabbits.

OBJECTIVES: A novel temperature-controlled intravascular radiofrequency balloon angioplasty (RFBA) technique was designed and developed for atherosclerosis (AS) management. METHODS: After establishing an AS model based on a balloon denudation injury of the abdominal aorta and a high cholesterol diet in rabbits, 46 animals were randomly assigned to the RFBA group (n = 28) or the plain balloon angioplasty (PBA) group (n = 28). The groups were further subdivided based on post-treatment euthanasia times (1 hour, 7 days, 14 days, and 28 days). Histopathological changes were observed by hematoxylin and eosin and Masson's staining. Immunohistochemistry, western blotting, and real-time quantitative polymerase chain reaction were used to detect changes in pro-inflammatory, anti-inflammatory, and apoptotic factors; TGF-ß/Smad-2 pathway protein Immune levels; and mRNA levels in tissues, respectively. RESULTS: The vascular lumen area in the RFBA group was larger than that in the PBA group at the same time points, although the change in the vascular lumen area was not different between groups. The expression of Bax, TGF-ß, Smad-2, and Caspase-3 in the RFBA group was significantly higher than that in the PBA group. The expression levels of Bcl-2 in the RFBA group were significantly lower than those in the PBA group. CONCLUSIONS: At 28 days, RFBA dilated the atherosclerotic blood vessels and thickened the fibrous cap of atherosclerotic plaques to promote plaque stability. RFBA was also found to activate apoptotic factors and the TGF-/Smad-2 inflammatory pathway.

CircRNA_0263 and circRNA_1507 are dysregulated in a rat model of atrial fibrosis induced by chronic intermittent hypoxia.

Aims: This study aimed to characterize circular RNA (circRNA) profiles associated with atrial fibrosis-related atrial fibrillation (AF) and reveal critical circRNAs for AF. Methods: Sprague Dawley rats were randomly divided into control and atrial fibrosis-related AF groups (n = 15 in each group). The rats in the atrial fibrosis-related AF group were induced by chronic intermittent hypoxia (CIH), and then confirmed by electrocardiograms, echocardiography, hematoxylin-eosin staining, Masson staining, immunohistochemistry assays and western blotting. After that, the atrial tissues were sent for circRNA sequencing, and the differentially expressed circRNAs were identified and validated by quantitative real-time polymerase chain reaction (qRT-PCR). Finally, a series of cell experiments were performed to explore the roles of two crucial circRNAs in rat atrial fibroblasts. Results: A CIH-induced AF model was successfully established in the rats. After sequencing, five upregulated and 11 downregulated circRNAs were identified in the CIH-induced AF group. These dysregulated circRNAs were primarily associated with "carbohydrate metabolism" and "cardiovascular diseases". Two circRNAs (circRNA_0263 and circRNA_1507) were predicted to regulate target gene expression by interacting with corresponding miRNAs, including rno-miR-29b-5p, rno-miR-29b-3p, rno-miR-496-5p, rno-miR-136-5p, and novel123-mature. Additionally, circRNA_0263 knockdown and circRNA_1507 overexpression inhibited the cell viability of fibroblasts, and downregulated the expression of fibrosis-related proteins. Conclusion: A series of circRNAs were identified as dysregulated in an AF rat model, and circRNA_0263 and circRNA_1507 might be crucial for atrial fibrosis-related AF development by competing with several miRNAs.

Comprehensive control of PM 2.5 capture and ozone emission in two-stage electrostatic precipitators.

Indoor air purification is extremely urgent to eliminate the health threat of PM 2.5, VOCs and microbial aerosol for exposing people, for which ESPs enjoy exceptional advantage for its special high-voltage characteristic. However, the secondary air pollutant of ozone is produced to possibly cause potential risk. In this work, six kinds of two-stage ESPs containing various charger and collector units, whose structure and size design are determined according to the indoor application, are developed to investigate the comprehensive control of PM 2.5 capture and ozone emission. Responsive surface methodology is employed to explore the relationship among ozone concentration, wire number, charger current and airflow velocity, and obtain regression model for predicting ozone emission. The comprehensive evaluation standard considering efficiency-ozone double factors is proposed to optimize structure design and working conditions of two-stage ESPs. Experimental results show that two-stage ESPs with a unit ratio of >3/4 can keep relatively good stable state, whose current reduction is in around 10 µA, for preventing particle charging function of charger from basically affecting. For the two-stage ESP with Ra = 2/5, it finds the optimization of working conditions of collector can bring rapid improvement of collection efficiency for 0.25 µm particles, which reaches up to be >60 %, while the optimization of that of the charger can only result in an enhancement of <30 %. RSM analysis exhibits a strong connection between the interactive effect of charger current and airflow velocity for presenting a steep response surface. Based on comprehensive control of PM 2.5 and ozone pollutants, it suggests the two-stage ESP with Ra = 2/5 is selected at the first priority and then that with Ra = 1/6, while two-stage ESP with Ra = 4/3 is not recommended for unsatisfied consequence of both of PM 2.5 capture and ozone emission.

Stereotactic Radiotherapy: An Alternative Option for Refractory Ventricular Tachycardia to Drug and Ablation Therapy.

Refractory ventricular tachycardia (VT) often occurs in the context of organic heart disease. It is associated with significantly high mortality and morbidity rates. Antiarrhythmic drugs and catheter ablation represent the two main treatment options for refractory VT, but their use can be associated with inadequate therapeutic responses and procedure-related complications. Stereotactic body radiotherapy (SBRT) is extensively applied in the precision treatment of solid tumors, with excellent therapeutic responses. Recently, this highly precise technology has been applied for radioablation of VT, and its early results demonstrate a favorable safety profile. This review presents the potential value of SBRT in refractory VT.

Establishment of a lncRNA-miRNA-mRNA network in a rat model of atrial fibrosis by whole transcriptome sequencing.

PURPOSE: Dysregulation of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) plays important roles in atrial fibrillation (AF). This study aimed to identify crucial lncRNAs, miRNAs, and mRNAs in AF based on whole transcriptome sequencing. METHODS: Thirty Sprague Dawley rats were randomly stratified into control and chronic intermittent hypoxia (CIH) groups (n = 15 in each). Hematoxylin-eosin staining, Masson staining, immunohistochemical assay, and western blotting were used to evaluate this model. Thereafter, atrial tissues were sent for whole transcriptome sequencing. Finally, fibrosis-related competing endogenous RNA (ceRNA) regulatory networks were built, and the relative levels of lncRNAs, miRNAs, and mRNAs were validated by real-time quantitative polymerase chain reaction (RT-qPCR) or western blotting. RESULTS: A CIH-induced atrial fibrosis rat model was successfully constructed. After sequencing, 268 differentially expressed lncRNAs (DELs), 20 differentially expressed miRNAs (DEMs), and 436 differentially expressed genes (DEGs) were identified. Functional analyses showed that these DEGs were associated with several processes and pathways, including "cell division," "IL-17 signaling pathway," "NOD-like receptor signaling pathway," and "cell adhesion molecules." Fibrosis-related ceRNA networks were then built, comprising five lncRNAs, seven miRNAs, and 19 DEGs. RT-qPCR and western blotting results showed that the patterns of lncRNAs (NONRATT016396.2, NONRATT001596.2, NONRATT011456.2), miRNAs (miR-10b-3p, miR-29b-3p), and mRNAs (Gng7 and Wnt2b) were consistent with sequencing analyses. CONCLUSIONS: The DELs, DEMs, and DEGs identified in this study may participate in atrial fibrosis processes, and the occurrence and progression of AF.

MiRNA21 and IL-18 levels in left atrial blood in patients with atrial fibrillation undergoing cryoablation and their predictive value for recurrence of atrial fibrillation.

PURPOSE: The recurrence of atrial fibrillation (AF) after cryoablation still needs to be prioritized, including discriminating predictive indicators. METHODS: Eighty-seven patients aged 43-83 years who underwent cryo-balloon ablation were divided into paroxysmal atrial fibrillation (PAF) and non-paroxysmal atrial fibrillation (non-PAF) groups. Baseline data, intraoperative index, and miRNA21, IL-18, NLRP3, and visfatin levels in peripheral venous blood and left atrial blood were assessed. Follow-up was performed for 6 months to observe the recurrence of AF. A Cox risk ratio model was used to analyze indicators for predicting AF recurrence. RESULTS: The non-PAF and PAF group recurrence rates of AF were statistically different (p < 0.05) at 9/22 (40.9%) and 11/65 (16.9%), respectively. Biomarker levels in the left atrial blood were higher in the non-PAF group than in the PAF group (p < 0.05). The effects of non-PAF and levels of miRNA21 and IL-18 in left atrial serum on the recurrence of AF after cryoablation statistically differed (p < 0.05). CONCLUSION: The levels of miRNA21 and IL-18 were higher in left atrial blood than in peripheral blood, which may be related to the severity of AF and recurrence of AF after cryoablation.

The experimental and simulation investigation of the dynamic characteristic of submicron-scale aerosol in high-voltage electric field by a visualization method.

The high-voltage electric field can effectively capture charged aerosols and has the effect of killing microbial aerosols simultaneously. In this article, an innovative visualization method for investigating the dynamic characteristic of submicron-scale aerosol particles in the high-voltage electric field is developed. Based on reasonable working principles and reliable experimental schemes, the movement of submicron-scale aerosol particles is observed and visualization images in different working conditions are photographed. Besides, with the aid of numerical method and solution of related equations, simulation researches on flow field distribution, electrostatic field characteristics, particle charging and motion behavior characteristics are also carried out. Visualization results prove the linear motion law of aerosol particles in an electric field of 0-3 kV/cm unit. As for 1 µm diameter particle, its migration velocity in 1 kV/cm electric field is measured as 0.016 m/s and 0.019 m/s after positive and negative charging of 1.5 kV voltage, respectively. A reliable calculation formula (η=(VjqpLj)/(3πµD2uxdp)) for predicting collection efficiency is derived and established based on actual particle migration velocity. The researches on the migration and capture law of submicron-scale aerosol in the high voltage electric field gives a key reference for the development and design of efficient removal of microbial aerosol and air purification equipment.

Identification of atrial fibrillation-associated lncRNAs and exploration of their functions based on WGCNA and ceRNA network analyses.

Atrial fibrillation (AF) is a common cardiac arrhythmia that induces serious complications. However, pharmacological treatments of AF remain challenging. This study aimed to screen crucial long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and messenger RNA (mRNAs) for AF using the microarray datasets (lncRNAs and mRNAs: GSE79768, GSE115574; miRNAs: GSE68475) collected from the Gene Expression Omnibus database. Weighted correlation network analysis of GSE79768 and GSE115574 datasets identified five modules were highly related to AF status. Among 118 module-related differentially expressed mRNAs, FBXW7, EGFR, CXCR2, ROCK1 and UBE2D1 were considered as hub genes according to the gene significance, module membership and the topological characteristics for the nodes in the protein-protein interaction network. lncRNA MIR100HG and LINC01105 may function by co-expressing with (MIR100HG-ROCK1/FBXW7/UBE2D1, LINC01105-EGFR) mRNAs or sponging miRNAs to regulate mRNAs (LINC01105-miR-125a-3p-EGFR, MIR100HG-miR-200b-3p- FBXW7, MIR100HG-miR-561-3p-CXCR2, MIR100HG-miR-548z-UBE2D1). Connectivity Map and Comparative Toxicogenomics Database searches predicted dexamethasone may treat AF by reversing the expression of MIR100HG; artemisinin may reverse the expression of hub DEGs. In conclusion, our results may provide novel molecular mechanisms and potential therapeutic targets and drugs for AF.

Benzene decomposition by non-thermal plasma: A detailed mechanism study by synchrotron radiation photoionization mass spectrometry and theoretical calculations.

Non-thermal Plasma (NTP) catalysis is considered as one of the most promising technologies to address a wide range of environmental needs, such as volatile organic compounds (VOCs) and NOx removal. To meet the updated environmental emission standard, the NTP catalysis reaction system needs to be better understood and further optimized. In this work, the degradation process of benzene in NTP, which is still regarded as a "black box" process, was explored by synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). For the first time, we observed over 20 representative species by PIMS and identified their structures accurately by photoionization efficiency (PIE) spectra. Phenol, acetylene and acrolein were recognized as the three main products. More intriguingly, concentration profiles demonstrated that a large amount of acrolein and also several higher-order products, which were usually neglected in previous research, were produced during the NTP destruction process. The details of the benzene degradation reaction mechanism, were finally established by the combination of SVUV-PIMS results, thermochemistry and theoretical calculations. This work helps to complete the mechanistic picture of plasma chemistry, which may be helpful on raveling the more complicated NTP catalysis mechanism in the future therefore contributing to design of improved NTP system for environmental applications.

Screening and functional analysis of differentially expressed lncRNAs in rapid atrial pacing dog atrial tissue.

PURPOSE: Atrial fibrillation (AF) is one of the most commonly sustained arrhythmias in clinical practice. Long non-coding RNAs (lncRNAs) are gene regulatory elements involved in the development of several diseases. We aimed to explore the expression characteristics of lncRNAs associated with AF. METHODS: We randomly assigned 12 adult healthy mongrel dogs into a control group and an atrial pacing group. Atrial pacing stimulation was performed at a high frequency of 500 beats per min for 14 consecutive days in the atrial pacing group. HE and Masson staining were used to detect rapid atrial pacing induced atrial fibrosis. Total RNA extraction was performed on dog atrial tissues and was used for high-throughput sequencing of lncRNAs. RESULTS: A total of 10,310 lncRNAs were detected, and 33 differentially expressed lncRNAs were screened. Among them, 19 lncRNAs were upregulated in the atrial pacing group, and 14 lncRNAs were downregulated. Gene Ontology (GO) classification, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and interaction networks showed that AF-related lncRNAs participate in the regulation of AF in diverse biological processes, cellular components, molecular functions, signaling pathways, and complex interactions with miRNAs and mRNAs. Five differentially expressed lncRNAs were selected for RT-PCR validation, and the verification results were consistent with the results of lncRNA sequencing. CONCLUSIONS: In summary, our study enhances our understanding of the biological functions of AF-related lncRNAs by screening and analyzing differentially expressed lncRNAs, and the results help to enrich the theoretical basis for the treatment of atrial fibrillation.

Catalytic oxidation of dimethyl phthalate over titania-supported noble metal catalysts.

Semi-volatile organic compounds (SVOCs) are organic compounds with the boiling point ranging between 240/260 ℃ and 380/400 ℃. Detailed knowledge regarding catalytic removal of SVOCs from indoor environment is very limited as it remains challenge to explore such reaction due to the viscosity nature of target contaminants. Here, we established a facile methodology to explore the heterogeneous catalytic oxidation reaction of dimethyl phthalate (DMP), a model SVOC, over the surface of supported catalyst. DMP was found to be gradually oxidized over the surface of titania supported catalysts including palladium (Pd), platinum and ruthenium with increasing temperature. The cleavage of side chain of DMP occurs at 75 ℃ over the surface of Pd/TiO2, which is significantly lower than that of the other two catalysts. Carbon dioxide was observed as the main product of the catalytic oxidation reaction. However, aromatic products and small molecule products were still observed as side-product in different temperature range. Density functional theory calculations further show that DMP can react with reactive oxygen species to form phthalic acid. While the cleavage of the DMP side chain occurs to form products such as methyl benzoate. This work thus provides basic knowledge about indoor SVOCs catalytic oxidation removal.

Catalytic activity of porous manganese oxides for benzene oxidation improved via citric acid solution combustion synthesis.

Various manganese oxides (MnOx) prepared via citric acid solution combustion synthesis were applied for catalytic oxidation of benzene. The results showed the ratios of citric acid/manganese nitrate in synthesizing process positively affected the physicochemical properties of MnOx, e.g., BET (Brunauer-Emmett-Teller) surface area, porous structure, reducibility and so on, which were in close relationship with their catalytic performance. Of all the catalysts, the sample prepared at a citric acid/manganese nitrate ratio of 2:1 (C2M1) displayed the best catalytic activity with T90 (the temperature when 90% of benzene was catalytically oxidized) of 212℃. Further investigation showed that C2M1 was Mn2O3 with abundant nano-pores, the largest surface area and the proper ratio of surface Mn4+/Mn3+, resulting in preferable low-temperature reducibility and abundant surface active adsorbed oxygen species. The analysis results of the in-situ Fourier transform infrared spectroscopy (in-situ FTIR) revealed that the benzene was successively oxidized to phenolate, o-benzoquinone, small molecules (such as maleates, acetates, and vinyl), and finally transformed to CO2 and H2O.

Removal of benzene by non-thermal plasma catalysis over manganese oxides through a facile synthesis method.

Three manganese oxide catalysts (MnOx) were synthesized via a simple method, and then they were introduced into the non-thermal plasma (NTP) system for benzene removal. The XRD and EXAFS results showed the MnOx were mainly in the Mn3O4 phase, and from the analysis of N2 adsorption/desorption isotherms, we knew the MnOx calcined at 250 °C (Mn250) had the largest surface area of 274.5 m2 g-1. Besides, Mn250 also exerted higher benzene adsorption capacity (0.430 mmol g-1) according to C6H6-TPD. O2-TPD indicated that Mn250 showed better oxygen mobility than Mn300. Moreover, by analyzing XPS results, it revealed that Mn250 exhibited rich abundant of surface adsorbed oxygen species (Oads) and moderate ratio of Mn4+/Mn3+, and the reducibility temperature was also the lowest among all the MnOx catalysts drawn by H2-TPR profiles. As a result, Mn250 combined with NTP could remove 96.9% of benzene at a low input power of 3 W (benzene concentration 200 ppm, and GHSV 60,000 mL gcat.-1 h-1), performing the best catalytic activity among the three catalysts and plasma only. Furthermore, the "NTP + Mn250" system also produced the highest CO2 concentration and lowest CO concentration in downstream, and the residual O3 after catalytic reaction was also the lowest, that is to say, the synergistic effect between NTP and Mn250 was more effective than other catalysts in benzene removal. Graphical abstract.