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The most traditional sites for electrodermal activity (EDA) data collection, palmar locations such as fingers or palms, are not usually recommended for ambulatory monitoring given that subjects have to use their hands regularly during their daily activities, and therefore, alternative sites are often sought for EDA data collection. In this study, we collected EDA signals (n = 23 subjects, 19 male) from four measurement sites (forehead, back of neck, finger, and inner edge of foot) during cognitive stress and induction of mild motion artifacts by walking and one-handed weightlifting. Furthermore, we computed several EDA indices from the EDA signals obtained from different sites and evaluated their efficiency to classify cognitive stress from the baseline state. We found a high within-subject correlation between the EDA signals obtained from the finger and the feet. Consistently high correlation was also found between the finger and the foot EDA in both the phasic and tonic components. Statistically significant differences were obtained between the baseline and cognitive stress stage only for the EDA indices computed from the finger and the foot EDA. Moreover, the receiver operating characteristic curve for cognitive stress detection showed a higher area-under-the-curve for the EDA indices computed from the finger and foot EDA. We also evaluated the robustness of the different body sites against motion artifacts and found that the foot EDA location was the best alternative to other sites. [ABSTRACT FROM AUTHOR]

As the main energy source for thermal power generation, coal generates a large amount of NOx during its incineration in boilers, and excessive NOx emissions can cause serious pollution to the air environment. Selective catalytic reduction denitrification (SCR) selects the optimal amount of ammonia to be injected for denitrification based on the measurement of NOx concentration by the automatic flue gas monitoring system. Since the automatic flue gas monitoring system has a large delay in measurement, it cannot accurately reflect the real-time changes of NOx concentration at the SCR inlet when the unit load fluctuates, leading to problems such as ammonia escape and NOx emission exceeding the standard. In response to these problems, this paper proposes an SCR inlet NOx concentration prediction algorithm based on BMIFS-LSTM. An improved mutual information feature selection algorithm (BMIFS) is used to filter out the auxiliary variables with maximum correlation and minimum redundancy with NOx concentration, and reduce the coupling and dimensionality among the variables in the data set. The dominant and auxiliary variables are then fed together into a long short-term memory neural network (LSTM) to build a prognostic model. Simulation experiments are conducted using historical operation data of a 300 MW thermal power unit. The experimental results show that the algorithm in this paper reduces the average relative error by 3.45% and the root mean square error by 1.50 compared with the algorithm without auxiliary variable extraction, which can accurately reflect the real-time changes of NOx concentration at the SCR inlet, solve the problem of delay in NOx concentration measurement, and reduce the occurrence of atmospheric pollution caused by excessive NOx emissions. [ABSTRACT FROM AUTHOR]

Southern corn rust (SCR), caused by the fungal pathogen Puccinia polysora , is a major threat to maize production worldwide. Efficient breeding and deployment of resistant hybrids are key to achieving durable control of SCR. Here, we report the molecular cloning and characterization of RppC , which encodes an NLR-type immune receptor and is responsible for a major SCR resistance quantitative trait locus. Furthermore, we identified the corresponding avirulence effector, AvrRppC, which is secreted by P. polysora and triggers RppC-mediated resistance. Allelic variation of AvrRppC directly determines the effectiveness of RppC -mediated resistance, indicating that monitoring of AvrRppC variants in the field can guide the rational deployment of RppC -containing hybrids in maize production. Currently, RppC is the most frequently deployed SCR resistance gene in China, and a better understanding of its mode of action is critical for extending its durability. This study identifies that an NLR-type immune receptor, RppC, confers resistance to southern corn rust caused by P. polysora in maize. Furthermore, it was found that an avirulence effector, AvrRppC, which is secreted by P. polysora , triggers RppC-mediated resistance, and that allelic variation of AvrRppC directly determines the effectiveness of RppC -mediated resistance. [ABSTRACT FROM AUTHOR]

Diesel particulate filter (DPF) active regeneration causes exhaust gas temperatures to be around 600°C, which not only affects the urea injections, but it also seriously affects the efficiency of the selective catalytic reduction (SCR), resulting in many difficulties in the control of tailpipe nitrogen oxides (NOx) emission and ammonia leakage. In this research, the influence of DPF active regeneration on SCR was experimentally studied with a bench. The influence of the DPF active regeneration on the SCR temperature, ammonia storage, urea injection, tail exhaust NOx, and ammonia leakage was quantitatively analyzed under the World Harmonized Transient Cycle (WHTC). The results showed that the average temperature of the SCR rose from 245°C to 502°C. The high temperature affected the SCR conversion efficiency, especially when the temperature exceeded 550°C. The SCR conversion efficiency decreased significantly, and the tail NOx changed from 0.12 g/kw-h to 0.65 g/kw-h. The sensitivity of the SCR conversion efficiency to the temperature was reduced, and the sensitivity to the space velocity was increased. When the temperature rose sharply, the dynamic follow-up of the ammonia storage and the ammonia leakage of the tailpipe were difficult to control. The concentration of the ammonia leakage was positively correlated with the space velocity. The control research results could provide a reference for SCR size design, control, and diagnosis strategies. [ABSTRACT FROM AUTHOR]

Polyoxymethylene dimethyl ethers (OME) are promising candidates as substitutes for fossil diesel fuel. A regenerative electricity-based production, using captured airborne carbon dioxide (CO2) and hydrogen (H2) from water electrolysis as reactants, provides a valuable contribution to the energy transition in mobile applications. Besides the possibility of carbon-neutral production, OME offer the advantage of a sootless combustion, which resolves the trade-off between soot and nitrogen oxides (NOx) emissions, and supports the efforts of air pollution control. While the emission behaviour of OME-powered diesel engines in raw exhaust has been studied extensively, interactions between this exhaust and components of the after-treatment system are mainly unknown. This study contains investigations conducted using a urea dosing variation (alpha titration) on a heavy-duty engine in combination with a system for selective catalytic reduction (SCR). These investigations showed a lower NOx reduction efficiency in OME operation in partial load operation compared with the one in fossil diesel operation. This can be attributed, among other reasons, to lower exhaust temperatures in OME operation. However, the high tolerance of OME to exhaust gas recirculation (EGR) compensates for this disadvantage because of the reduction of the raw NOx emission level. The difference in SCR efficiency disappeared at a high load operation point. Additionally, the alpha titration revealed, that urea dosing decreases formaldehyde emission in the SCR system. A pre-conditioned WHSC and WHTC cycle demonstrated the potential of an OME engine with after-treatment in the form of a twin-dosing SCR system for ultra-low emissions. For the specific evaluation of the emissions during these test cycles, this study contains the detailed calculation of the required factors – so-called ' u -values'– for OME exhaust according to the technical standard UN/ECE R49. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, a series of MO x -modified (M = Mn, Fe, and Ce) CrO x -WO x mixed oxides were synthesized via the sol-gel technique for the selective catalytic reduction of NO x with NH 3. Given the addition of MnO x or CeO x , the availability of the catalyst surface acid sites tended to decline, which negatively affected the proceeding of the deNO x process. Moreover, the retention of oxidative ability by introducing MnO x also favored the over-oxidation of NH 3 , which accelerated the additional formation of NO x and created a crucial barrier for the increment in the higher-temperature deNO x activity. Apparently, <80 % of the NO x could be effectively eliminated from the working gas within the whole temperature range for the CrCeW and CrMnW samples. By contrast, doping FeO x was able to introduce ample acid sites onto the catalyst surfaces, which was beneficial for the adsorption of NH 3 and subsequently the facilitation of the progression of the deNO x process. Furthermore, the weakened oxidizability suppressed the over-oxidation of NH 3. Consequently, a broad operating temperature window was obtained for the FeO x -doped catalyst; >90 % NO x conversion efficiency was achieved in the temperature range of 230–450 °C. During the deNO x process, the Eley-Rideal mechanism dominated over the four investigated samples. [Display omitted] • Adding MnO x and CeO x improves the oxidizability of CrW at the cost of the acidity. • Doping FeO x introduced plentiful acid sites onto the CrW catalyst surface. • >90 % NO x conversion is obtained between 230 and 450 °C for the CrFeW catalyst. • The Eley-Rideal mechanism dominates during the SCR reaction over the catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mo-S-Mo group in MoS 2 hinders HSO 4 − intermediates, inhibiting SO 3 formation. • Low-valence reduced S enhances catalyst reducibility and reduces SO 3 production. • S2− with SO 3 effectively reduces SO 3 to SO 2 and S, lowering the SO 3 content. • Dense pore structure, high thermal stability, and reducibility limit SO 2 oxidation. • New catalysts inhibit SO 2 /SO 3 conversion more than V-Ti and V-Mo/Ti catalysts. The utilization of commercial vanadium-titanium based catalysts (V 2 O 5 /TiO 2) within the selective catalytic reduction (SCR) process is a prominent contributor to the emergence of sulfur trioxide (SO 3) in coal-fired boiler environments. The direct modification of vanadium-titanium based catalysts has big potential to be an efficacious strategy for in-situ inhibiting SO 3 formation. This research evaluates the effectiveness of MoS 2 modified V 2 O 5 /TiO 2 catalyst on SO 2 oxidation under diverse conditions, using controlled condensation for SO 3 collection. The results showed that V 2 O 5 -MoS 2 /TiO 2 catalysts outperformed conventional V 2 O 5 /TiO 2 catalysts in inhibiting the oxidation from SO 2 to SO 3 between 200 and 400 °C, with optimal performance at 350 °C. No significant effect was observed on the catalytic oxidation of SO 2 when the O 2 concentration was lower than that of SO 2 , whereas the introduction of appropriate quantities of NO promoted the generation of SO 3. The excessive inclusion of NH 3 nearly doubled the SO 3 generation rate, increasing it from 0.284 % to 0.434 %. The NO and NH 3 mixture markedly reduced SO 3 generation to 0.085 % at a 62 mL/min mixture concentration, just 30 % of the rate without the mixture. Following the reaction of SO 2 and O 2 , the reacted catalyst exhibited reduced pore volume, enhanced thermochemical stability, and lower susceptibility to SO 2 catalytic oxidation. The addition of low-valence sulfur improves catalyst reducibility, reduces V5+–OH reactions in various atmospheres, and decreases the formation of sulphate and gaseous SO 3. The Mo-S-Mo group also effectively prevents the formation of HSO 4 − intermediates. Additionally, MoS 2 reacts with SO 3 via a reduction reaction, significantly lowering the SO 3 levels. Finally, in diverse atmospheric conditions, the catalysts maintained their V5+ content and catalytic efficiency, thus improving SCR performance stability. [ABSTRACT FROM AUTHOR]

• The temperature distribution of SCR carrier was tested by 9 sensors. • The effects of different post injection strategies on NO x emission and NO x conversion efficiency were studied. • The SCR temperature management strategy under WHTC transient conditions was proposed. Selective catalytic reduction technology is the main technology to reduce NO x emissions from diesel engines. In order to meet the increasingly stringent requirements of pollutant emission regulations and further reduce the low-temperature NO x emissions in the transient conditions of diesel engines, it is necessary to perform exhaust thermal management on diesel engines. Taking a diesel engine equipped with DOC + DPF + SCR + ASC aftertreatment system as the research object, the internal temperature of the SCR carrier was tested by arranging nine thermocouple temperature sensors inside the SCR carrier. The effects of different post-injection strategies (without post-injection, post-injection2, post-injection1, and post-injection2 + post-injection1) on the SCR temperature characteristics and NO x emissions were studied under WHTC condition. The results show that the center temperature was high and the edge temperature was low inside the SCR carrier. In terms of SCR average temperature, the post-injection strategies from highest to lowest were post-injection2 + post-injection1, post-injection1, post-injection2, and without post-injection. For the comparison of NO x conversion efficiency, results show that post-injection1 > post-injection2 > post-injection2 + post-injection1. Under WHTC conditions, the use of post-injection2 + post-injection1 for the first 700 s and post-injection1 for the last 700 s was the best choice for reducing NO x emissions. [ABSTRACT FROM AUTHOR]

• The effect of components in flue gas on commercial SCR catalyst was summarized. • The mechanisms of multifactorial synergism on VWT catalysts were first clarified. • Comprehensive approach to extend the lifetime of commercial catalysts was presented. • Concepts for catalyst lifetime prediction and management were reported. NO x does great harm to the environment and human beings. The selective catalytic reduction (SCR) of NO x with NH 3 is proven to be a mature technology to eliminate NO x from the waste gas, in which V 2 O 5 -WO 3 (MoO 3)/TiO 2 is the commercialized catalyst system. Lifetime is recognized as an important parameter to evaluate the practicality of the catalyst. However, this parameter is difficult to determine because of the variable flue gas conditions. Therefore, it is necessary to understand the impacts of different components on the deNO x performance of the catalysts so that rational lifetime management methods can be adopted. This advance would be introduced in this review first. Then the synergistic effects of multi-poisons on the catalysts would be summarized and illustrated. In accordance with these studies, some modification was conducted to enhance the catalyst's anti-poisoning ability to achieve the goal of prolonging the lifetime of the catalysts. Moreover, the latest research advances in the lifetime prediction of the SCR catalysts and the relevant management systems were summarized in the following section. This paper aims to provide theoretical guidance for simulating the catalyst deactivation process under actual conditions and shows a direction for constructing catalyst lifetime management systems. [ABSTRACT FROM AUTHOR]

Cu/SSZ-13 is a catalyst commonly used for selective catalytic reduction (SCR) of nitrogen oxides (NO x) in diesel engine exhaust. Standard configurations are based on SCR preceded by an oxidation catalyst, however, a close-coupled SCR configuration appears relevant for upcoming regulations addressing cold-start emissions. Two often discussed ion-exchanged Cu sites in Cu/SSZ-13 are denoted ZCuOH and Z 2 Cu, where Z represents an Al atom in the zeolite framework. Mild hydrothermal aging (HTA) causes Cu redistribution within the catalyst; ZCuOH sites transform into more stable Z 2 Cu species. In this work, the effect of mild HTA on NH 3 , NO, SO 2 , and CO oxidation is studied on a commercial Cu/SSZ-13 sample. Temperature-programmed reaction experiments, performed in a lab reactor, and previously published catalyst characterization data using H 2 -TPR, NH 3 -TPD, and DRIFTS were used to build and validate a mathematical model. It couples the kinetics of the oxidation reactions with ZCuOH and Z 2 Cu concentration evolution during mild HTA. The model uses two distinct rate coefficients for ZCuOH and Z 2 Cu sites, allowing prediction of the catalyst activity during aging. The results suggest that the rate coefficients for the studied reactions on Z 2 Cu are effectively nil, so the observed activity in NH 3 , NO, SO 2 , and CO oxidation can be attributed solely to ZCuOH sites. [Display omitted] • Cu sites transformation from ZCuOH to Z 2 Cu described by a kinetic model. • Distinct rate coefficients for NH 3 , NO, SO 2 and CO oxidation on ZCuOH and Z 2 Cu. • Analysis of TPR experiments suggests the activity is correlated to ZCuOH sites. • The developed model predicts catalyst activity changes during mild hydrothermal aging. [ABSTRACT FROM AUTHOR]

This article illustrated the effects of iron precursors on the deNO x performance of the CeO x -FeO x catalysts. With regard to the catalyst prepared using Fe(NO 3) 3 as the iron precursor (CeFe–N), relatively poor deNO x performance was observed; <80% NO x conversion was obtained at 130–450 °C. While for the samples synthesized using FeCl 3 and Fe 2 (SO 4) 3 as the iron sources (CeFe–C and CeFe–S), >90% of the NO x was effectively removed from the working gas in the temperature range of 230–350 °C and >270 °C, respectively, signifying the broadened operational temperature range. The superior oxidative ability of metal cations primarily contributed to a low activation energy, which was favorable for the activation of the reactants and the acceleration of the reaction via the "fast SCR" pathway at lower temperatures. Meanwhile, a comparatively low availability of the surface acid sites signified the limited adsorption of NH 3 , which thus endowed CeFe–N with a low pre-exponential factor and primarily caused the restrained proceeding of the SCR reaction. In contrast, the presence of ample acid sites and the weakened oxidative ability of metal cations successively explained the increased pre-exponential factor and activation energy of CeFe–C and CeFe–S. The synergistic effects of the previously indicated two factors enabled these two catalysts to have a higher or similar low-temperature NO x conversion compared with CeFe–N. With increasing the temperature, the additional generation of NO x was favored over CeFe–N, causing a decline in its NO x conversion efficiency. On the contrary, the inhibited proceeding of NH 3 over-oxidation ensured most NH 3 to serve as the reductant to reduce NO x on CeFe–C and CeFe–S, which mainly explained their comparatively broad operational temperature window. • The CeFe–C and CeFe–S catalysts exhibit a wide operating temperature range. • The activation energy is related to the reactivity of the catalysts' metal cations. • The pre-exponential factor is related to the number of catalysts' surface acid sites. • The Eley-Rideal mechanism dominates the SCR reaction over CeFe–S and CeFe–N. • The Langmuir-Hinshelwood mechanism also describes the SCR pathways over CeFe–C. [ABSTRACT FROM AUTHOR]

[Display omitted] • Potential PM 2.5 generation mechanism caused by NH 3 -SCR is revealed. • NH 3 spillover and SO 2 oxidation in SCR lead to NPF through nucleation. • Nuclei concentration is increased by 2–5 orders with temperature below 320 °C. • Nuclei concentration is decreased with increase in ratio of NH 3 to NO. Air pollution caused by particulate matters with diameter smaller than 2.5 μm (PM 2.5) has aroused widely concern for the past decades. As a main precursor for the PM 2.5 , NO x emission is strictly control by flue gas denitrification with ammonia-based Selective Catalytic Reduction (SCR). However, the widely application of SCR causes unexpected increase in primary PM concentration in the flue gas, which may induce heavier particle pollutions. Herein, a multicomponent nucleation model with consideration of NH 3 spillover and SO 2 oxidation is established, to clarify the PM generation dynamics during SCR process and provide effective mitigation strategies. The NH 3 slipping rate is decreased by temperature increasing, and is enhanced by X NH3 /X NO. While the variation of SO 2 oxidation rate is opposite to that of NH 3 slipping rate, which may be attributed to their competitive adsorption on the SCR catalyst surface. With temperature varied from 320 °C to 420 °C and X NH3 /X NO changed from 0.7 to 1.2, the NH 3 slipping rate and SO 2 oxidation rate falls in the range of 3 %–11 % and 1 %–2%, respectively. Concentration of NH 3 and SO 2 would be increased in the SCR equipment, leading to gas-to-particle nucleation and PM generation. The nuclei concentration C nuclei can be sharply increased by 2–5 orders of magnitude with temperature below 320 °C. With a constant temperature and increased X NH3 /X NO from 0.7 to 1.2, the C nuclei would be decreased owe to the decreased SO 2 oxidation. Therefore, reducing the SO 2 oxidation as well as preventing NH 3 from spillover during the SCR can be effective way to mitigate the potential PM emission. [ABSTRACT FROM AUTHOR]

• TiO 2 modified limonite was prepared through impregnation method. • TiO 2 /Limonite had excellent deNOx activity, water and sulfur resistance. • The lattice defects and weakness acidity helped low-temperature deNOx activity. Limonite was used as a precursor and TiO 2 as a modifier to synthesize TiO 2 /Limonite composites through the wet impregnation method. The influences of the TiO 2 doping amount, the calcination temperature on the denitration efficiency and the structure and properties of composites were systematically studied. The results showed that the modified catalyst over the Ti/Fe mass ratio was 0.07 and the calcination temperature was 300°C exhibited excellent catalytic activity, good stability, and remarkable resistance to water and sulfur dioxide within reaction temperature of 100 ∼ 240°C. When NO initial concentration was 0.05 % and gas hourly space velocity (GHSV) was 36,000 h−1 and the reaction temperature was 130°C, the NO conversion efficiency reached 100 %, and the N 2 selectivity was 99.6 %. When the catalyst was exposed to 10 %H 2 O at 150°C, it maintained a 100 % NO conversion efficiency. In the presence of 10 %H 2 O and 50 ppm SO 2 at 200°C, the NO conversion efficiency remained at 100 %. The TiO 2 /Limonite catalyst possessed improved performance due to the introduction of the anatase TiO 2 , which led to more lattice defects, weak Lewis acid sites, and higher adsorbed oxygen mobility. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • >90 % NOx conversion is obtained in 230–390 °C with the W/Cr molar ratio fixed at 0.8. • The operation temperature window of CrOx shifts to higher temperatures via adding WOx. • Adding WO3 enhances the acidity of the catalyst at the cost of its oxidative ability. • E-R mechanism dominates in the SCR reactions over the CrOx and CrOx-WOx catalysts. A series of CrO x –WO x mixed-oxide catalysts was synthesized through the citric acid-assisted sol–gel method and used in the selective catalytic reduction of NO x with NH 3 to eliminate NO x. The pristine CrO x displayed certain deNO x activity, achieving >90 % NO x conversion efficiency at the temperature range of 210 °C–230 °C. Its robust oxidative ability facilitated efficient activation of adsorbed NH 3 , contributing to relatively high low-temperature activity. However, at higher temperatures, the increased over-oxidation of NH 3 led to additional NO x formation. Moreover, the comparatively weak acidity resulted in a lower NH 3 coverage on the CrO x surface, causing a deficiency in reductant NH 3 for NO x reduction and consequently a decrease in high-temperature activity. With WO x addition, the acidity of the catalysts was enhanced, which was primarily responsible for the high NH 3 coverage on the catalysts' surfaces. Furthermore, the reduction in the reactivity of Cr6+ and the number of chemisorbed oxygen species slowed NH 3 activation and inhibited NH 3 over-oxidation, shifting the catalyst's operating temperature window toward higher ranges. At a fixed W/Cr molar ratio of 0.8, >90 % NO x was eliminated at the temperature range of 230 °C–390 °C. However, the relatively weak resistance of the CrO x –WO x mixed oxide to SO 2 or Na, together with the irrecoverable deactivation upon long exposure to these two components, suggests the need for further modification to enhance the practicality of the catalyst. [ABSTRACT FROM AUTHOR]

Low sintering flue gas temperatures and large temperature fluctuations require the development of low-temperature and efficient SCR (selective catalytic reduction) catalysts suitable for the sintering process. It has been shown that modified Mn-Ce/TiO2 catalysts have good denitration capability and have potential commercial use. In this experiment, TiO2-loaded Mn and Ce SCR catalysts were prepared using the impregnation method, and a series of characterizations of the samples were carried out to illustrate the effect of the active material on the denitration efficiency. The kinetic analysis provides theoretical as well as data support for the subsequent optimization of the SCR catalysts. The results show that the denitration efficiency of the catalysts can reach 93.86% when the Mn content is 10% and the Ce content is 3%. The doping of active substances can increase the specific surface area, total pore volume and average aperture of the catalysts and improve the adsorption capacity of the catalysts.

The Cu/SSZ-13 catalyst with Si/Al ratio of 10 and Cu/Al ratio in the range of 0.005 to 0.5 was synthesized by ion exchange method. The effect of Cu/Al ratio on the performance, selectivity, and active center of the catalyst SCR was studied. The samples with too low Cu/Al ratio have low catalytic activity in the entire temperature range due to the small number of active sites. The samples with too high Cu/Al ratio have good performance in the low temperature range due to the large number of active sites. However, a large amount of copper that has not undergone ion exchange will generate CuO, which greatly enhances the oxidation of NH3 at high temperatures, which in turn leads to a decrease in catalytic performance at high temperatures. XRD and BET experiments show that all catalyst samples have good CHA crystal structure and microporous structure, and the pore size is mostly about 2 nm. In situ DRIFTS analysis shows that when the Cu/Al ratio is low, the proportion of Z2Cu in the active sites is higher, and the stability of the catalyst is enhanced. When the copper–aluminum ratio is high, the proportion of ZCuOH increases, and the low-temperature activity of the catalyst is higher. [ABSTRACT FROM AUTHOR]

Vanadia-based catalysts are widely used in selective catalytic reduction (SCR) reaction for reducing nitrogen oxides emissions, however, they only exhibit sufficient DeNOx efficiency within a narrow temperature window. In this study, a catalyst embedded with electrothermal alloy was prepared. The catalyst surface temperature could be heated using the electrothermal alloy, in order to widen the operating temperature window of the V2O5-WO3/TiO2 catalyst. Experimental results revealed that the electrothermal alloy embedded V2O5-WO3/TiO2 catalyst can maintain superior NH3-SCR performance and high resistance to H2O in a wide gas temperature range of 100-400 °C by controlling the surface temperature. In the meantime, the NH4HSO4 poisoned catalyst could be efficiently regenerated through electric heating, and NOx conversion can be restored to the level of fresh samples. Additionally, the effect of additives including methylcellulose and glass fiber, on the physicochemical properties of the plate-type catalyst was also investigated, and the catalyst samples were characterized by means of BET, XRD, NH3-TPD, H2-TPR, TG and SEM-EDS. This study proves the electric heating strategy is a promising way to enhance the performance of the V2O5-WO3/TiO2 during wide temperature SCR applications. [ABSTRACT FROM AUTHOR]

Superior capsule reconstruction (SCR) is a treatment option for irreparable massive rotator cuff tears (MRCT). The purpose of this study is to describe a classification system for graft integrity and tear location. Patients who underwent SCR at a single institution were included. Pre-operative age, gender, prior surgery, Hamada grade, and Goutallier stage were recorded. An MRI was performed postoperatively to assess graft integrity and tear location. 53 patients met inclusion criteria. Mean age was 60.1 ± 7.9 years. A post-operative MRI was performed in 42 (80%) patients at a mean of 14 ± 7 months (range, 6–40 months). MRIs demonstrated an intact graft in 16 (38%) shoulders. Of the 26 graft tears, 14 (54%) were from the glenoid, 5 (19%) mid-substance, 6 (23%) from the tuberosity, and 1 (3.8%) had complete graft absence. Graft tears are common following SCR. We describe four different graft tear locations and submit a classification system that can be used in future studies to better compare outcomes based on graft integrity and tear location. Clinical correlation with graft integrity and graft tear location needs to be further investigated. • Post-operative MRI is used to assess graft integrity and tear location. • A new classification system for graft integrity and tear location is being introduced. • We describe graft intact and four different graft tear locations. • The classification can be used in future studies to better compare outcomes based on graft integrity and tear location. • Clinical correlation with graft integrity and graft tear location needs to be further investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] Vanadia-based catalysts are widely used in selective catalytic reduction (SCR) reaction for reducing nitrogen oxides emissions, however, they only exhibit sufficient DeNO x efficiency within a narrow temperature window. In this study, a catalyst embedded with electrothermal alloy was prepared. The catalyst surface temperature could be heated using the electrothermal alloy, in order to widen the operating temperature window of the V 2 O 5 -WO 3 /TiO 2 catalyst. Experimental results revealed that the electrothermal alloy embedded V 2 O 5 -WO 3 /TiO 2 catalyst can maintain superior NH 3 -SCR performance and high resistance to H 2 O in a wide gas temperature range of 100–400 °C by controlling the surface temperature. In the meantime, the NH 4 HSO 4 poisoned catalyst could be efficiently regenerated through electric heating, and NO x conversion can be restored to the level of fresh samples. Additionally, the effect of additives including methylcellulose and glass fiber, on the physicochemical properties of the plate-type catalyst was also investigated, and the catalyst samples were characterized by means of BET, XRD, NH 3 -TPD, H 2 -TPR, TG and SEM-EDS. This study proves the electric heating strategy is a promising way to enhance the performance of the V 2 O 5 -WO 3 /TiO 2 during wide temperature SCR applications. [ABSTRACT FROM AUTHOR]

Bare titania and metal-promoted TiO2 catalysts were employed in the treatment of nitrates, which are ubiquitous pollutants of wastewater. The results show that the process can be carried out under visible light (from a white light LED lamp) and, in the best case, 23.5% conversion of nitrate was obtained over 4 h with full selectivity towards N2 by employing 0.1 mol% Ag/TiO2 prepared by flame spray pyrolysis. Moreover, the performance was worse when testing the same catalysts with tap water (11.3% conversion), due to the more complex composition of the matrix. Finally, it was found that photoreduction of nitrate can be effectively performed in combination with photo-oxidation of ammonium without loss in the activity, opening up the possibility of treating highly polluted wastewater with a single process. The latter treatment employs the two contaminants simultaneously as electron and holes scavengers, with very good selectivity, in a completely new process that we may call Photo-Selective Catalytic Reduction (Photo-SCR). [ABSTRACT FROM AUTHOR]

[Display omitted] • The effect of reducing agent on SCR of NO x over Ag/Al 2 O 3 catalyst was studied. • Alcohols give better performances than aliphatic and aromatic hydrocarbons. • NMR T 1 / T 2 measurements show that alcohols have higher surface affinity for the catalyst. • A correlation between NMR T 1 / T 2 measurements and reaction activation temperature is established. • Adsorption properties of reducing agents over the catalyst are important in determining the SCR catalyst activity. NMR relaxation has been used to characterise the strength of surface interaction of reducing agent species in Ag/Al 2 O 3 catalysts used for the selective catalytic reduction (SCR) of NO x. Several classes of compounds, including aliphatic and aromatic hydrocarbons, as well as alcohols, were investigated. The results show that the strength of interaction of the reducing agent with the catalyst surface, characterised by the NMR relaxation time ratio T 1 / T 2 , plays an important role in determining the catalyst performances, with reducing agents able to compete with water for adsorption over the surface giving better catalytic activities. In particular, a clear trend was observed when comparing the T 1 / T 2 ratio of different reducing agents with the initial activity of the catalyst, in particular with the activation temperature, with species such as alcohols, which showed a higher affinity with the catalyst, showing an easier initial activation. Whilst SCR is a complex reaction, whereby a series of phenomena are responsible for the overall catalytic activity, the strength of surface interaction of the reducing agent is a useful indicator for the initial catalytic activation in such processes. [ABSTRACT FROM AUTHOR]

To study the effect of different modification reagents on activated carbon (AC), HNO3, H2SO4, H2O2, H2C2O4, and H3PO4 were chosen to modify AC. Then a series of Mn/AC catalysts were prepared by impregnation method. The denitrification performance and SO2 adsorption activities of these catalysts were tested. The results indicated that the catalyst prepared by HNO3-modified AC has both the highest NO conversion and SO2 adsorption activity. The NO conversion can reach 80% at 180 °C and SO2 saturated adsorption time can reach 30 min. To investigate the enhanced modification mechanisms of HNO3, the various modified samples were characterized by SEM-EDS, XPS, FTIR, and NH3-TPD. And the results show HNO3 can effectively increase the amount of chemical adsorbed oxygen on the surface of AC. And on the other hand, the nitrogen-containing functional groups introduced by HNO3 can promote the adsorption of NO, thus improving the denitrification performance. As a result, HNO3 can play a better role in activating AC, and the catalyst modified by HNO3 is more conducive to be used as the carrier of SCR catalysts. [ABSTRACT FROM AUTHOR]

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Background The clinical use of serum creatine (sCr) and cystatin C (CysC) in kidney function evaluation of critically ill patients has been in continuous discussion. The difference between estimated glomerular filtration rate calculated by sCr (eGFRcr) and CysC (eGFRcysc) of critically ill COVID-19 patients were investigated in this study. Methods This is a retrospective, single-center study of critically ill patients with COVID-19 admitted in intensive care unit (ICU) at Wuhan, China. Control cases were moderate COVID-19 patients matched in age and sex at a ratio of 1:1. The eGFRcr and eGFRcysc were compared. The association between eGFR and death were analyzed in critically ill cases. The potential factors influencing the divergence between eGFRcr and eGFRcysc were explored. Results A total of 76 critically ill COVID-19 patients were concluded. The mean age was 64.5 ± 9.3 years. The eGFRcr (85.45 (IQR 60.58–99.23) ml/min/1.73m2) were much higher than eGFRcysc (60.6 (IQR 34.75–79.06) ml/min/1.73m2) at ICU admission. About 50 % of them showed eGFRcysc < 60 ml/min/1.73 m2 while 25% showed eGFRcr < 60 ml/min/1.73 m2 (χ2 = 10.133, p = 0.001). This divergence was not observed in moderate group. The potential factors influencing the divergence included serum interleukin-6 (IL-6), tumor necrosis factor (TNF-α) level as well as APACHEII, SOFA scores. Reduced eGFRcr (

This paper reports the design and analysis of scalable Sudoku-type diode-triggered silicon-controlled rectifier (DTSCR) electrostatic discharge (ESD) protection structures fabricated in a foundry 22nm fully-depleted silicon-on-insulator (FDSOI) technology. 3D TCAD and ESD testing confirm that the Sudoku DTSCR ESD structures can dramatically improve the ESD area efficiency. Transmission line pulse (TLP) measurement shows a high ESD area efficiency of ~6.47mA/ $\mu \text{m}^{2}$ for Sudoku-DTSCR, ~64.6% improvement over traditional finger-DTSCR structure. A scalability model was derived as design guidelines for optimizing Sudoku DTSCR ESD protection array structures.

The inflow uniformity before selective catalytic reduction (SCR) catalyst carrier is a major issue for DeNOx capability of diesel engine after-treatment. Through the construction of the numerical model and CFD simulation of six perforated plate variations with different structural and positional characteristics, the influence of perforated plates on the uniformity of the airflow velocity at the inlet of the SCR catalyst carrier was analyzed. Comparison of different perforated plate variations shows that the encircling flow is a major hindrance to achieve higher inflow uniformity. Enclosed flow passage can remove the encircling flow and increase inflow uniformity at the cost of increased pressure drop. Rational layout of the perforated plate can achieve uniformity increase, while decrease pressure drop. High-velocity exhaust coupled with larger holes can improve both uniformity and pressure drop. The uniformity index increased from 97.6% of the original design to 98.7% of the optimized design, while pressure drop increased from 11.20 to 12.09 kPa. Weighing the relationship between inflow uniformity and pressure drop is an issue worthy of attention.

Active components reloading is critical process for the catalyst regeneration, which is limited by the low adsorption capacity and unwilling distribution of desired components to the catalyst surface. Herein we demonstrated that with dimethyl formamide(DMF) modification and sequentially reloading of vanadium, the traditional V-Ti SCR catalyst, which uses vanadium as the active components and titanium as the carrier, showed the significantly improved DeNOx performance, owing to the increased adsorption capacity and desired distribution of vanadium. When the DMF concentration was 6%, the adsorption capacity of the promoted catalyst was 3.58 and 6.57 mg/g under vanadyl ion concentrations of 1.5 and 3 g/L, respectively, 135 and 147% higher than that of the original catalyst. Adsorption kinetics demonstrated that the pseudo-second-order kinetic model better describes the process by which vanadyl ions adsorb onto the catalyst. In addition, the adsorption equilibrium indicated that Langmuir model was a closer fit for the vanadyl ion adsorption to the promoted catalyst. After DMF modification, the vanadyl ions were first adsorbed onto the functional groups on the catalyst surface, substantially increasing the vanadium loading on the catalyst surface while limiting the increase in vanadium content within the interior of catalyst, which was conducive to enhancing the DeNOx activity and reducing the increase in the SO2/SO3 conversion. When the vanadium adsorption capacity was 3.5 mg/g, the increase in the DeNOx activity of the promoted catalyst was 68.1% higher than that of the original catalyst, whereas the increase in SO2/SO3 conversion was 28.9% lower than that of the original catalyst. Thus, in the regeneration of SCR catalysts vanadium initial concentration and loading could be reduced.

[Display omitted] • Nano Al 2 O 3 layer is coated on Cu-SSZ-13 by chemical liquid deposition (CLD). • High-Temperature SCR activity of aged Cu-SSZ-13 is preserved by Al modification. • Aggregated Cu is passivated as CuAlO 2 that are inert for NH 3 oxidation. • CuAl 2 O 4 and Al 2 O 3 , comparing with CuO, have higher affinity for Cu(OH) 2. • CuAl 2 O 4 forms with Al modification and captures detached Cu as CuAlO 2 upon aging. To improve the hydrothermal durability of Cu-SSZ-13 selective catalytic reduction (SCR) catalyst, a thin Al 2 O 3 modification layer was coated on the external surface of Cu-SSZ-13 by a chemical liquid deposition (CLD) method. The high-temperature SCR activity of the Al-modified Cu-SSZ-13 can be maintained upon 750–800 °C hydrothermal aging, and over-oxidation of NH 3 is largely inhibited. Based on H 2 -TPR and EPR results, it is revealed that CuAl 2 O 4 -like species forms upon Al modification and converts further to CuAlO 2 -like species during aging, while the accumulation of CuO-like species is inhibited. The high affinity of Al-containing species (i.e. , Al 2 O 3 and CuAl 2 O 4 -like species) with Cu(OH) 2 is suggested by DFT calculations, indicating that Cu(OH) 2 detached from ion-exchange sites are captured by Al to form CuAlO 2 -like species instead of CuO-like species. The passivation of detached Cu species by coated Al leads to somewhat weakened low-temperature SCR activity, but successfully preserves the high-temperature SCR performance upon aging, which can be applied to high-temperature SCR scenarios. [ABSTRACT FROM AUTHOR]

The experiment research of SCR catalysts with monometallic iron or polymetal as the active centers and three typical porous materials such as carbon-based materials, zeolite and metal-organic frameworks materials as the carriers is reviewed. The catalytic performance of SCR after Fe loading was analyzed, and the main problems were weak sulfur and water resistance and poor high-temperature stability of metal-organic frameworks materials. The catalytic performance of the ferri-based multi-pore material catalys can be improved by treating the precursor and compounding other metals to them. [ABSTRACT FROM AUTHOR]

The clinical use of serum creatine (sCr) and cystatin C (CysC) in kidney function evaluation of critically ill patients has been in continuous discussion. The difference between estimated glomerular filtration rate calculated by sCr (eGFRcr) and CysC (eGFRcysc) of critically ill COVID-19 patients were investigated in this study. This is a retrospective, single-center study of critically ill patients with COVID-19 admitted in intensive care unit (ICU) at Wuhan, China. Control cases were moderate COVID-19 patients matched in age and sex at a ratio of 1:1. The eGFRcr and eGFRcysc were compared. The association between eGFR and death were analyzed in critically ill cases. The potential factors influencing the divergence between eGFRcr and eGFRcysc were explored. A total of 76 critically ill COVID-19 patients were concluded. The mean age was 64.5 ± 9.3 years. The eGFRcr (85.45 (IQR 60.58–99.23) ml/min/1.73m2) were much higher than eGFRcysc (60.6 (IQR 34.75–79.06) ml/min/1.73m2) at ICU admission. About 50 % of them showed eGFRcysc < 60 ml/min/1.73 m2 while 25% showed eGFRcr < 60 ml/min/1.73 m2 (χ2 = 10.133, p = 0.001). This divergence was not observed in moderate group. The potential factors influencing the divergence included serum interleukin-6 (IL-6), tumor necrosis factor (TNF-α) level as well as APACHEII, SOFA scores. Reduced eGFRcr (<60 mL/min/1.73 m2) was associated with death (HR = 1.939, 95%CI 1.078–3.489, p = 0.027). The eGFRcr was generally higher than eGFRcysc in critically ill COVID-19 cases with severe inflammatory state. The divergence might be affected by inflammatory condition and illness severity. Reduced eGFRcr predicted in-hospital death. In these patients, we advocate for caution when using eGFRcysc. [ABSTRACT FROM AUTHOR]

Several models involving spray atomization, wall impingement, evaporation and urea pyrolysis were built through a commercial code to study the influence of parameters of Urea Selective Catalytic Reduction (Urea –SCR) injection system on critical performances at low exhaust temperatures. The spray development, NH3 concentration distribution and wall film thickness have been studied. Results suggest that the wall impingement of the Urea Water Solution (UWS) is more at the temperature of 180°C than at 430°C. Lower temperatures tend to hinder evaporation and pyrolysis. NH3 concentration is uneven at low temperatures and the fuel film generated on the wall is also incomplete. Low temperatures could help injection system with a tilting nozzle raise its injection pressure and accelerate the evaporation and pyrolysis of the droplets. The distribution of spray impingement, however, is narrower and the fuel film thickness on the wall is increased. Smaller injection angle made it easier to expel gas stream and the droplets would then follow the direction of the gas stream. The droplets distribution is therefore more uniform and the spray wall-impingement reduced. [ABSTRACT FROM AUTHOR]

This study describes a Cu-based selective cata-lytic reduction (SCR) model, which considers temperature, ammonia storage, and space velocity. An ammonia loss factor is proposed, and a specific algorithm is given. The ammonia loss factor is used to correct the ammonia storage and nitrogen oxide (NOx) conversion efficiency. The model is tested on a test bench under the World Harmonized Transient Cycle (WHTC) and the World Harmonized Stationary Cycle (WHSC), and the model is tested on a vehicle for urban, suburban, and high-speed road conditions. The results show that under the WHTC, the cumulative deviation between the NOx conversion efficiency predicted by the model and the NOx con-version efficiency calculated by the sensor is —0.2%; under the WHSC, the cumulative deviation between the two is —0.41 %; and under vehicle conditions, the cumulative deviation between the two is 0.36%. A new finding in this study is that for the monolithic catalyst, the ammonia loss factor and the NOx conversion efficiency corresponding to the rising phase and the falling phase of ammonia storage are not co-incident. These new insights can optimize the control strategy of automotive SCR. [ABSTRACT FROM AUTHOR]

A general definition of the 1-year premium risk in non-life insurance is given, which fully covers the risk associated with the change in premium provision. Based on the chain ladder method, a simple predictor is provided and a new analytic formula for the estimated prediction error is derived. Furthermore, the relationship with the claims development result is explicitly worked out. Finally, the formula is applied to publicly available data of a legal protection insurance company falling under Solvency II; and the resulting confidence intervals are compared to the reported premium risk capital. [ABSTRACT FROM AUTHOR]

In this study, a series of CuW/CeZr (denoted as xCu–yW–CZ hereafter) catalysts with both NO reduction and CO oxidation activity was synthesized by the co-impregnation method, aiming for simultaneous removal of NO and CO under oxygen-rich conditions. Characterizations including N2 adsorption and desorption, XRD, SEM, H2–TPR, and NH3–TPD were used to interpret the influence of WO3/CuO loading amount on catalytic activity. The results suggested that the addition of WO3 species increased the surface acidity of the catalyst while weakening its redox property. On the contrary, the addition of CuO species greatly enhanced the redox property of the catalyst while hardly changing its surface acidity. Notably, too high content CuO was prone to aggregate, which was unfavorable to catalytic activity. Consequently, 5Cu–10W–CZ with 5 wt% CuO and 10 wt% WO3 presented the most optimal catalytic activity because of high components dispersion, appropriate redox property, and surface acidity. A novel dual-function catalyst (CuW/CeO2–ZrO2) that can simultaneously catalyze NH3–SCR reaction and CO oxidation reaction, was synthesized by the co-impregnation method, aiming for simultaneous removal of NO and CO under oxygen-rich conditions. [ABSTRACT FROM AUTHOR]

Imagery‐based extinction procedures have long been used in the treatments of fear‐related conditions. The assumption is that imagery can substitute for the perceptual stimuli in the extinction process. Yet, experimental validations of this assumption have been limited in number and some have relied exclusively on measures of autonomic reactivity without consideration of conscious feelings of fear. The current investigation sought to assess whether imagery‐based exposure could lead to extinction of conditioned fear to the corresponding perceptual stimulus. Conditioned fear responses were measured by both a physiological (i.e., skin conductance response [SCR]) and a subjective (i.e., self‐reported fear) measure. Participants (N = 56) first underwent perceptual differential fear conditioning, then imagery extinction, then perceptual extinction. SCR evidence was found for successful fear conditioning, generalization of fear from viewing to imagery, and most importantly, the absence of differential fear after imagery extinction upon re‐exposure to the conditioned perceptual stimulus. Self‐reported fear confirmed the acquisition and generalization of fear and provided evidence of a significant reduction in differential fear conditioning across extinction. Consistent with clinical evidence of the efficacy of imagery extinction and the existing limited experimental literature, this study offers support for fear extinction to perceptual stimuli via imagery exposure. The present study provides experimental evidence that imagery of a fear conditioned stimulus can produce differential fear extinction as measured both physiologically (i.e., skin conductance response) and subjectively (i.e., self‐reported fear), which extends the extant literature of mental imagery and fear extinction. These findings provide empirical support for the clinical application of extinction‐based imagery treatments in fear‐related affective disorders. [ABSTRACT FROM AUTHOR]

Environmentally benign cerium-based catalysts are promising alternatives to toxic vanadium-based catalysts for controlling NO x emissions via selective catalytic reduction (SCR), but conventional cerium-based catalysts unavoidably suffer from SO 2 poisoning in low-temperature SCR. We develop a strongly sulfur-resistant Ce 1+1 /TiO 2 catalyst by spatially confining Ce atom pairs to different anchoring sites of anatase TiO 2 (001) surfaces. Experimental results combined with theoretical calculations demonstrate that strong electronic interactions between the paired Ce atoms upshift the lowest unoccupied states to an energy level higher than the highest occupied molecular orbital (HOMO) of SO 2 so as to be catalytically inert in SO 2 oxidation but slightly lower than HOMO of NH 3 so that Ce 1+1 /TiO 2 has desired ability toward NH 3 activation required for SCR. Hence, Ce 1+1 /TiO 2 shows higher SCR activity and excellent stability in the presence of SO 2 at low temperatures with respect to supported single Ce atoms. This work provides a general strategy to develop sulfur-resistant catalysts by tuning the electronic states of active sites for low-temperature SCR, which has implications for practical applications with energy-saving requirements.

In order to solve the poor flow performance issues of selective catalytic reduction (SCR) denitration systems, the effect of the static mixer on the flow field was studied using computational fluid dynamics (CFD) numerical simulations. Based on the analysis of the original SCR denitration system, two static mixers were selected to explore their influence on system performance. The results show that both static mixers can effectively improve the denitration performance under different conditions. The static mixer with a rotating arrangement showed a better performance in the uniformity of concentration. The pressure loss without a static mixer is 834 Pa, and the pressure loss increases by 94 Pa and 73 Pa for rotating and X-arranged static mixers, respectively. Meanwhile, a static mixer will increase energy loss. Therefore, power plants can choose the layout of their static mixers according to the actual situation to achieve the optimal performance.

In this paper, an improved low-voltage-triggered silicon-controlled rectifier (LVTSCR) called an ultra-low-voltage-triggered SCR (ULVTSCR) is proposed and fabricated in a 40-nm CMOS process. By adding an external NMOSs-chain triggering component to the conventional LVTSCR, the proposed ULVTSCR can realize ~2 V lower trigger voltage. Meanwhile, the trigger voltage of the ULVTSCR is adjustable with the number of its incorporated NMOS transistors. Compared with the existing Diodes-chain Triggered SCR (DTSCR) scheme, the NMOSs-chain triggered ULVTSCR possesses a 25% lowered overshoot voltage in the same area consumption, and thus it is more suitable for 2.5 V circuits ESD protections considering the CDM protection applications.

CeNbTi catalyst was poisoned in different sulfur poisoning atmospheres at 300 °C for 6 h and then was evaluated for selective catalytic reduction (SCR) of NOx with NH3. The catalyst deactivation upon SO2 exposure was effectively inhibited in the presence of NH3. Temperature-programmed decomposition (TPD) analyses were applied to identify deposit species on the poisoned catalysts by comparison with several groups of reference samples. Diffuses reflectance infrared Fourier transform spectroscopy (DRIFTS) over CeNbTi catalysts with different poisoning pretreatments and gas purging sequences were designed to investigate the roles of NH3 in the removal of surface sulfites and sulfates. More ammonium sulfates including ammonium bisulfate and ammonium cerium sulfate were generated instead of inert cerium sulfate in these conditions. The mechanisms about the formation and transformation of surface deposits upon sulfur poisoning w/wo NH3 were explored, which provided a basis for developing Ce-based mixed oxides as SCR catalysts for stationary sources.

A new design of a sorption-selective catalytic reduction (SCR) system is proposed to improve ammonia storage density and meet the ammonia demand for high NOx conversion efficiency at a relatively lower temperature (2 as the main ammine and NH4Cl as the start-up ammine is further analyzed as an example to be used in the sorption-SCR system for a diesel engine, the NOx emissions of which were experimentally measured in different operation modes. Based on the experimental data of engine emissions and kinetic models of the chemisorption between ammines and ammonia, the dynamic performance of the sorption system with a total capacity of 180 L sorbent composite in different layouts was investigated and compared. It was found that the achievable desorption conversion degree was lower in smaller reactors and was more sensitive to operating conditions in smaller reactors compared to larger reactors. This suggests that a system using a small reactor layout requires some extra volume to completely meet the required capacity compared to a larger reactor layout. However, because systems with large reactors tend to respond slowly, as they have more thermal mass and take a longer time for preparation, there is a design trade-off required to have optimal performance and balance between the main unit and the start-up unit. In the case studied in this work, a system using three rechargeable reactors with a volume of 60 L each was found to be the preferable layout; it could have about a 90% desorption conversion degree and required around 10 min of warm-up time. Meanwhile, the coupled start-up unit should have a capacity of around 165 mL at least.

To address the environmental pollution caused by nitrogen oxides, V2O5-WO3/TiO2 is widely used as a catalyst based on selective catalytic reduction (SCR) technology. However, spent SCR catalysts pose a potential hazard to the environment due to the presence of heavy metals. This problem continues to plague countries with predominantly thermal power generation, and landfills as the dominant disposal method wastes significant metal resources. Previous research into the recovery of these metal resources has received considerable attention. Here, we summarise the methods of recovery and find that research trends are beginning to move towards improving the added value of recovered products. One very promising application is photocatalysts; however, the atomic efficiency of current methods is not satisfactory. Therefore, this review first focuses on the regeneration of spent SCR catalysts and the processes used for elemental extraction to clarify what forms of V, W and Ti can be obtained from existing processes. This is followed by providing directions for the conversion of spent SCR catalysts into photocatalysts with improvements based on such processes. From a different perspective, this also provides a new resource for photocatalysts and is expected to significantly reduce the cost of photocatalyst production.

Operando spectroscopy combines the in situ determination of material structure by spectroscopy/diffraction techniques with the measurement of material performance, which is conversion/selectivity in the field of heterogeneous catalysis. A central question in operando spectroscopy is whether the signatures visible by the characterization methods are responsible for catalyst performance. Individual analytical methods can provide useful information, but their combination (multi-technique approach) is essential to obtain a complete perspective on molecular reaction mechanisms. This approach must be coupled to experimental protocols and mathematical algorithms enabling the ability to disentangle the contribution of the active structure from the unresponsive one. Here, we report an account with examples from our own research activities in catalysis science., (Copyright 2024 Filippo Buttignol, Luca Maggiulli, Ilia Kochetygov, Ivo Alxneit, Davide Ferri. License: This work is licensed under a Creative Commons Attribution 4.0 International License.)

The simultaneous removal of NOx and dioxins has been considered an economical and effective technology of controlling multipollutant flue gas in the context of "carbon peaking and carbon neutrality". However, this technology has not yet been implemented in practical situations, because the interactive relationship between the selective catalytic reduction (SCR) reaction and dioxin catalytic oxidation lacks a deep understanding, especially on a carbon-based catalyst. In this research, the influence of NO and NH 3 on the oxidation characteristics and byproducts distribution of dibenzofuran (DBF) was studied on V 2 O 5 /AC catalyst. Results indicated that NH 3 has a stronger inhibition effect for DBF catalytic oxidation than NO due to obvious competitive adsorption between NH 3 and DBF on the V 2 O 5 /AC catalyst. In addition, although both NO and NH 3 inhibit the complete degradation of DBF, their effects on the byproduct distribution are not consistent. NO primarily affects the level of oxygen-containing byproducts, while NH 3 primarily affects the level of alkane byproducts. Furthermore, the SCR reaction activity demonstrated a reduction when DBF was present. The occupation of V 2 O 5 sites by DBF and its oxidizing intermediates has hindered the production of monodentate nitrate and the reactivity of bridged nitrate, resulting in a decrease in SCR activity via the L-H mechanism. This work aims to provide theoretical guidance for simultaneous removal of NOx and dioxins in industrial fumes.