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Compared with industrial hydrogen production methods, photocatalytic decomposition of water for hydrogen production has the advantages of clean and pollution-free. In order to overcome the shortcomings of catalysts in the process of photocatalytic decomposition of water to produce hydrogen and improve the hydrogen evolution efficiency of photocatalysts, researchers have summarized some of the latest improvement methods for three types of photocatalysts : TiO2 photocatalyst, transition metal sulfide photocatalyst, and g-C3N4 photocatalyst, mainly including morphology regulation, element doping, noble metal precipitation, and the synthesis of composite photocatalysts. The photocatalytic decomposition of water to produce hydrogen is still limited by hydrogen evolution efficiency, cost factors, and complex catalyst construction methods. Finding suitable cocatalysts at an appropriate price, designing more practical means of constructing photocatalysts, and obtaining photocatalysts with higher hydrogen resolution efficiency are still the directions that researchers need to focus on. [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of CO2 to hydrocarbons is expected to simultaneously alleviate the energy crisis and greenhouse effect. Herein, the ternary BiOCl/C/Cu2O catalysts with different mass ratios were compounded using a simple hydrothermal method, revealing better photocatalytic activity than the monomer. In the absence of sacrificial agents and photosensitizers, 25% BiOCl/C/Cu2O showed optimal photocatalytic performance. The CO and CH4 yields over 25% BiOCl/C/Cu2O reached 26.77 and 9.86 μmol g−1 h−1, which is 2.9 and 8.7 times higher than that of the pristine Cu2O, respectively. The ameliorative activity can be attributed to the construction of the Z-scheme heterostructure and carbon layer, which are conducive to the transfer and separation of photogenerated carriers. This study offers valuable references for the design and investigation of a Z-scheme heterojunction using a carbon layer as an electron transfer medium. [ABSTRACT FROM AUTHOR]

In this study, a remarkable offset deactivation effect of K and P on MnEuOx SCR catalyst has been found. Experimental results showed that the NO conversion over K−P poisoned catalyst was close to 80 % at 250 °C. Several characterization techniques containing NH3‐TPD, XPS, H2‐TPR, XRD and in situ DRIFT were used to reveal the mechanism of the offset effect. The characterization of NH3‐TPD and H2‐TPR suggested that the introduction of P on MnEuOx‐K could improve its surface acidity and redox ability. Moreover, the content of chemisorbed oxygen and Mn4+ were markedly restored under the situation that the toxic elements were coexistent on catalyst surface. The strong interaction between K and P might be the major reason for the offset deactivation effect. More specifically, PO3− species were preferentially bonded with the surface potassium species and released MnO2 active sites poisoned by K. Therefore, the highly active MnO2 sites might be protected and the catalytic activity could be restored. [ABSTRACT FROM AUTHOR]

A series of Sb-doped CeVO 4 samples were synthetized by hydrothermal method and used in selective catalytic reduction of NO with NH 3. Contrasted with other catalysts, Sb 2 CeVO 4 possessed superior NH 3 -SCR activity and excellent SO 2 tolerance. Besides, the characterization results testified that Sb species in Sb 2 CeVO 4 could reduce the crystallization of CeVO 4 , and improve the surface acidity and reducibility. Moreover, the existence of Sb3+ was beneficial to generate more surface adsorbed oxygen species. Based on the in situ DRIFT spectra, more ad-NH 3 and ad-NO x species with higher reactivity were obtainable on Sb 2 CeVO 4 catalyst compared with that on CeVO 4 catalyst, which also contributed to enhancing the SCR activity by Langmuir-Hinshelwood (L-H) mechanism effectively. Image 1 • Sb modification could improve the SCR performance of CeVO 4 catalyst. • Sb3+ was beneficial to generate more surface adsorbed oxygen species. • More active ad-NH 3 and ad-NO x species were available on Sb 2 CeVO 4 catalyst. [ABSTRACT FROM AUTHOR]

CO pretreatment was found to effectively improve the SCR performance of CeO2, with over 90% at about 300 °C. The larger specific area and the decrease of CeO2 crystallization indicated the modification of the surface structure after CO pretreatment. Abundant Ce3+ species and active oxygen, better reducibility, and the higher surface adsorption capacity were mainly responsible for its enhanced SCR performance. DRIFT analysis revealed the presumed coexistence of two reaction routes that the L-H mechanism was related to the reaction temperature, while the reaction rate of E-R route was almost directly proportional to the NO concentration at a certain temperature, based on the kinetic calculation. In addition, the CO-pretreated CeO2 also exhibited a better poisoning tolerance for SO2 and H2O and excellent thermal stability and circularity. [ABSTRACT FROM AUTHOR]

TiO 2 supported Ce Mo catalyst (Ce Mo/TiO 2) were employed for the first time to simultaneously oxidize elemental mercury (Hg0) and reduce nitrogen monoxide (NO) under simulated SCR atmosphere. The combination of molybdenum oxides and cerium oxides exhibits obvious synergy for Hg0 oxidation and NO reduction. Ce Mo/TiO 2 -0.3 catalyst exhibited an excellent Hg0 oxidation and NO reduction efficiencies of over 90% at above 250 °C corresponding to gas hourly space velocity (GHSV) of 119,000 h−1 (NO reduction) and 1,190,000 h−1 (Hg0 oxidation). Brunauer-Emmett-Teller (BET) surface area was not the dominating factor affecting the Ce Mo/TiO 2 performance. Well-dispersion of active species, abundant chemisorbed oxygen and large surface oxygen capacity were responsible for its high catalytic activity. The presence of Hg0 exhibited a negligible effect on NO reduction. Low-concentration of NO inhibited the Hg0 oxidation while a relatively high concentration had a promotional effect inversely due to abundant NO 2. NH 3 consumed surface oxygen and competed to adsorb with Hg0 resulting in the deactivation of Hg0 oxidation while an excellent recovery was observed after simultaneous cutting off NH 3 and introduction of O 2. In addition, Ce Mo/TiO 2 -0.3 catalyst also presented an excellent resistance to SO 2 and H 2 O poisoning and a good stability and recyclability. The possible mechanism for simultaneous NO reduction and Hg0 oxidation was proposed for Ce Mo/TiO 2 catalysts. The process of NO reduction and Hg0 oxidation over Ce-Mo/TiO2 catalyst. Image 1 • It is the first time that Ce Mo/TiO 2 catalyst was employed for the research of simultaneous Hg0 oxidation and NO reduction. • Low-concentration of NO inhibited the Hg0 oxidation while a relatively high concentration had a promotional effect. • The presence of Hg0 exhibited a negligible effect on NO reduction. • Ce Mo/TiO 2 -0.3 catalyst had an excellent recovery for NH 3 inhibition and resistance to SO 2 poisoning. [ABSTRACT FROM AUTHOR]

In present study, the poisoning mechanism of Cl on V/TiO 2 catalyst for SCR removal of NOx using NH 3 as the reductant was explored by in situ DRIFT technique. The experimental results revealed that the existence of Cl did not change the SCR reaction mechanism over V/TiO 2 catalyst, which was mainly under the control of both E-R and L-H mechanisms. The deactivation of V/TiO 2 catalyst by Cl was mainly resulted from the inhibited adsorption of NH 3 and NOx species, accompanied by the decrease of the reactivity of adsorbed NH 3 species. Image 1 • The addition of Cl on V/TiO 2 catalyst has an inhibition effect on the adsorption of NH 3 and NOx species. • The reactivity of adsorbed NH 3 species over V/TiO 2 catalyst would decrease after the loading of Cl. • The addition of Cl on V/TiO 2 catalyst does not change the mechanism of NH 3 -SCR reaction over it. [ABSTRACT FROM AUTHOR]

Fe was used as the modifier to improve the performance of CeZr2Ox catalyst for the selective catalytic reduction (SCR) reaction with ammonia. Experimental results revealed that proper Fe species (Fe/Ce molar ratio = 2) could effectively improve the SCR activity of CeZr2Ox, along with the elevated resistance to SO2 and H2O. The characterization results including BET, XRD, H2-TPR and NH3-TPD confirmed that Fe species in Fe2CeZr2Ox catalyst could inhibit the formation of ZrO2 crystals and lead to higher reducibility and surface acidity. In addition, more Ce3+ and surface active oxygen species could be detected on Fe2CeZr2Ox compared with CeZr2Ox. By means of in situ DRIFT technique, it could be deduced that the SCR reaction process over Fe2CeZr2Ox was accelerated mainly through theL-H pathway due to the advanced adsorption of NH3 and NOx species, along with the promoted NO conversion to NO2. Therefore, the modification of CeZrOx catalyst by Fe had a significant stimulation effect on its low-temperature SCR performance. [ABSTRACT FROM AUTHOR]

The extensive use of fossil fuels in residential and industrial fields has resulted in massive emission of gaseous pollutants, which poses a severe threat to the environment and human health. Consequently, it is critical to develop affordable air cleaning technology, catalytic oxidation is one of the most promising technologies for this purpose. CeO 2 -based catalysts with special morphologies have aroused widespread attention because of their environmental friendliness, surface binding defects, excellent redox ability, and significant oxygen storage capacity. In addition, the morphologies of these catalysts also modulate the valence state of the element, defect sites, and acid-base properties. Therefore, they have been extensively utilized to reduce air pollutants. In this review, the preparation and application of CeO 2 -based catalysts with special morphologies, such as hollow, cubic, rod-like, and others, have been summarized, followed by an in-depth examination of the advantages and mechanisms of these catalysts toward eliminating air pollutants. Finally, the challenges associated with the preparation and application of CeO 2 -based catalysts with special morphologies are presented. We hope to provide some reference for the future design and synthesis of novel CeO 2 -based catalysts used for the abatement of gas pollutants. [Display omitted] • The preparation and application of CeO 2 -based catalysts with special morphologies are introduced. • The application of CeO 2 -based catalysts with special morphologies for air pollutants abatement are presented. • Reaction mechanisms of air pollutants abatement based on CeO2-based catalysts with special morphologies are discussed. [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of CO2 to hydrocarbons is expected to simultaneously alleviate the energy crisis and greenhouse effect. Herein, the ternary BiOCl/C/Cu2O catalysts with different mass ratios were compounded using a simple hydrothermal method, revealing better photocatalytic activity than the monomer. In the absence of sacrificial agents and photosensitizers, 25% BiOCl/C/Cu2O showed optimal photocatalytic performance. The CO and CH4 yields over 25% BiOCl/C/Cu2O reached 26.77 and 9.86 μmol g−1 h−1, which is 2.9 and 8.7 times higher than that of the pristine Cu2O, respectively. The ameliorative activity can be attributed to the construction of the Z-scheme heterostructure and carbon layer, which are conducive to the transfer and separation of photogenerated carriers. This study offers valuable references for the design and investigation of a Z-scheme heterojunction using a carbon layer as an electron transfer medium. [ABSTRACT FROM AUTHOR]

[Display omitted] As a renewable green energy, hydrogen has received widespread attention due to its huge potential in solving energy shortages and environment pollution. In this paper, a one-step solvothermal method was applied to grow ultra-thin g-C 3 N 4 (UCN) nanosheets and NiS nanoparticles on the surface of ZnIn 2 S 4 (ZIS). A ternary NiS/ZnIn 2 S 4 /ultra-thin-g-C 3 N 4 composite material with dual high-speed charge transfer channels was constructed for the advancement of the photocatalytic H 2 generation. The optimal ternary catalyst 1.5wt.%NiS/ZnIn 2 S 4 /ultra-thin-g-C 3 N 4 (NiS/ZIS/UCN) achieved a H 2 evolution yield reached to 5.02 mmolg−1h−1, which was 5.23 times superior than that of pristine ZnIn 2 S 4 (0.96 mmolg−1h−1) and even outperform than that of the best precious metal modified 3.0 wt%Pt/ZnIn 2 S 4 (4.08 mmolg−1h−1). The AQY at 420 nm could be achieved as high as 30.5%. The increased photocatalytic performance of NiS/ZIS/UCN could be ascribed to the type-I heterojunctions between intimated ZIS and UCN. In addition, NiS co-catalyst with large quantity of H 2 evolution sites, could result in efficient photo-induced charges separation and migration. Furthermore, the NiS/ZIS/UCN composite exhibited excellent H 2 evolution stability and recyclability. This work would also offer a reference for the design and synthesis of ternary co-catalyst with heterojunction composite for green energy conversion. [ABSTRACT FROM AUTHOR]

• MnCoO x @TiO 2 nanocage catalysts derived from the Prussian blue analogue exhibited excellent SCR performance and SO 2 tolerance. • The SCR reaction pathways based on both L-H and E-R mechanisms were investigated. • More ad-NH 3 and ad-NO x species with higher reactivity are available on the surface of the MnCoO x @TiO 2 catalyst. • The synergistic effect of the MnCoO x core and TiO 2 shell is crucial to the SCR reaction and SO 2 resistance. By annealing the self-assembled Mn 3 [Co(CN) 6 ] 2 ·nH 2 O@Ti(OH) 4 , MnCoO x @TiO 2 double-walled nanocage catalysts were obtained. Excellent low-temperature NH 3 -SCR performance (above 90 % NO conversion efficiency at 200–325 °C), acceptable stability, and exceptional SO 2 resistance were demonstrated. According to a series of characterizations, the MnCoO x @TiO 2 catalysts were found to have an enlarged specific surface area, improved surface acidity and redox ability, enhanced dispersion of active components, and abundantly formed adsorbed oxygen (O ads) species, which consequently exhibited the improved deNO x performance. Meanwhile, the coating of the TiO 2 shell reduced the basic sites to adsorb SO 2 , hence leaving a certain proportion of active metal oxides preserved. Apparently, the MnCoO x @TiO 2 catalysts were observed to have an enhanced SO 2 -resistant ability. [ABSTRACT FROM AUTHOR]

[Display omitted] • The introduction of HCl generates more Brønsted acid sites and improves surface acidity of the CeMo catalyst. • Poisoning the CeMo-Na catalyst with HCl could enhance its SCR performance due to the offsetting effect of Na&HCl. • The SCR reactions over the samples all follow both the E-R and L-H reaction mechanisms. This work mainly illustrated the synergistic effects of Na and HCl on the SCR performance of CeMo catalysts. Given that the fresh CeMo catalyst was treated with HCl or doped by Na, the weakened acidity and oxidizability would interfere with the adsorption and activation of NH 3 , thus resulting in a downward trend of the catalyst deNO x performance. Notably, for the HCl treated Na-poisoned catalyst, the treatment with HCl introduced additional acid sites onto the Na-poisoned catalyst surface and increased the availability of Ce4+ and chemisorbed oxygen. These behaviors exerted a certain promotional effect on the adsorption and activation of NH 3. Apparently, the catalyst's deNO x performance slightly rebounded, suggesting the offsetting effects of HCl. Such knowledge would be vital to the stable operation in real coal-fired flue gas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pr-modified MnCeO x catalysts exhibited excellent SCR performance and SO 2 tolerance. • The SCR reaction pathways based on both L-H and E-R mechanisms were investigated. • The ad-NH 3 species on MnCePrO x -0.3 showed superior reactivity. • Abundant of O ads and Mn4+ on MnCePrO x -0.3 catalysts promoted the "fast SCR". Using a one-step impregnation method, a series of Pr-modified MnCeO x catalysts with different Pr molar ratios were created to manufacture an efficient and effective catalyst for low-temperature NH 3 -SCR. It was demonstrated that the Pr modification could extensively boost the MnCeO x catalysts' de-NO x activity and SO 2 resistance and led to the formation of a unique broom-like morphology, especially when the molar ratio of Pr/Mn = 0.3, the MnCePrO x -0.3 exhibited above 90 % NO conversion at 250 °C with the existence of 100 ppm SO 2. According to the characterization results, the enhancement of Pr doping for MnCeO x catalysts was mainly manifested by the expanded specific surface area, the improved dispersion of active components, the enhanced surface acidity and redox ability, and the generated more chemisorbed oxygen (O ads) species. All these characteristics allowed the NH 3 -SCR reaction over MnCePrO x -0.3 catalysts to proceed through the both Eley-Rideal (E-R) and Langmuir-hinshelwood (L-H) mechanism. [ABSTRACT FROM AUTHOR]

A sequence of Cr-modified CeZr 2 O x catalysts were synthesized through the co-precipitation way and applied in selective catalytic reduction (SCR) of NO x with ammonia. The optimal catalyst (Cr 1 CeZr 2 O x) exhibited the excellent NH 3 -SCR activity and high SO 2 resistance. From the characterization results, Cr species in Cr 1 CeZr 2 O x could suppress the formation of ZrO 2 crystals, which could also contribute to stronger surface acidity and reducibility. Besides, more Ce3+ and surface adsorbed oxygen species were observed on Cr 1 CeZr 2 O x catalyst. On the basis of in situ DRIFT experiments, it could be confirmed that the NH 3 -SCR process on Cr 1 CeZr 2 O x was promoted through Langmuir-Hinshelwood (L-H) mechanism. Besides, the improved NO oxidation and more ad-NO x and ad-NH 3 also played a vital role for the superior low-temperature SCR activity of Cr 1 CeZr 2 O x. Unlabelled Image • Cr 1 CeZr 2 O x catalyst shows higher SCR activity and SO 2 tolerance. • The addition of Cr on CeZr 2 O x catalyst could generate more ad-reactants. • Cr in CeZr 2 O x catalyst could improve the reactivities of ad-reactants. [ABSTRACT FROM AUTHOR]

Sb-modified Mn/TiO 2 catalyst synthetized by sol–gel method exhibited outstanding performance in simultaneous Hg0 oxidation and NO reduction under SCR conditions at low temperature. NO removal (>90%) and Hg0 oxidation (>80%) were simultaneously obtained over MnSb/TiO 2 -0.25 catalyst in 200–300 °C with a GHSV of 54,000 h−1. Moreover, MnSb/TiO 2 -0.25 catalyst exhibited excellent tolerance to SO 2 and H 2 O. Characterization results suggested that the well-dispersed Mn, Sb and Ti species, along with the enriched Mn4+ and surface oxygen species on Mn-Sb/TiO 2 -0.25 catalyst should play a critical role in its excellent catalytic performance. The formed HgO had little inhibition effect on NO reduction over MnSb/TiO 2 -0.25 catalyst. And the coexistence of NO and O 2 has a promotion effect on Hg0 oxidation, while NH 3 exhibited an inhibition effect on oxidation of Hg0. In SCR reaction process, the Hg0 oxidation efficiency was suppressed, but this effect could be basically eliminated by using a relatively low GHSV value. Thus using MnSb/TiO 2 -0.25 for simultaneous Hg0 oxidation and NO reduction in SCR reactor may be workable in coal-burning power plants. Based on the results of experiments and characterizations, the mechanism of synchronous removal of Hg0 and NO on MnSb/TiO 2 -0.25 catalyst could be described as:Hg0(ad)+O α (O β)→HgO(ad), NO(g)+NO 2 (ad)+NH 3 (ad)→N 2 +H 2 O. Image 1 • NO removal (>90%) and Hg0 oxidation (>80%) are achieved on MnSb/TiO 2 -0.25 catalyst. • MnSb/TiO 2 -0.25 catalyst exhibits good SO 2 /H 2 O resistance. • The reaction mechanism of simultaneous removal of NO and Hg0 is proposed. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The MoP/CN samples exhibit superior activity in CO 2 reduction and H 2 evolution. • The CO 2 adsorption and conversion progress is well revealed in the photoreaction. • The efficient co-catalyst MoP facilitates the separation and transfer of charges. Abstract Photoreduction CO 2 to hydrocarbons and photosplitting water for H 2 production are the most promising, sustainable approaches for environmental pollution alleviation and solar-to-chemical energy conversion. However, developing low-cost, high efficient and stable photocatalysts remains a great challenge. Herein, we reported a novel visible-light activated MoP co-catalyst loaded g-C 3 N 4 photocatalyst for CO 2 reduction and water splitting under simulated irradiation firstly. Experimental results demonstrated that the composites were highly active and exhibited superior stability. The maximum CO and H 2 evolution rates of 0.92 μmol h−1 and 40.38 μmol h−1 were achieved on MoP/CN-15% catalyst, which were 4.5-fold and 74.5-fold higher than the pure g-C 3 N 4 , and the corresponding apparent quantum efficiencies (AQE) were 3.5% and 18.3% at 420 nm, respectively. In situ FTIR analysis disclosed the CO 2 adsorption and conversion progress, in which the COO− acted as a major intermediate. Furthermore, comprehensive characterization analysis revealed the introduction of MoP facilitated the separation and transfer of photogenerated electron-hole pairs, and the theoretical calculation by density functional theory (DFT) also confirmed that MoP could effectively separate the photoexcited charges from g-C 3 N 4. Combining with experimental and DFT calculations results, a new way to design cost-effective photocatalysts has been enlightened. [ABSTRACT FROM AUTHOR]

[Display omitted] • The modification of TiO 2 support with Zr could enhance the K resistance of Ce/TiZrO x catalyst. • The use of TiZrO x support could promote the adsorption of NH 3 and NO x species. • The SCR reaction over Ce/TiZrO x catalyst is accelerated via l -H route. Potassium, as one of the alkali metals, could cause significant deactivation on the Ce-based SCR catalysts. In this work, Zr-doping was found to efficiently enhance the K tolerance of Ce/TiO 2 catalyst. The BET, XRD, Raman, XPS, H 2 -TPR, NH 3 -TPD, O 2 -TPD and NO x -TPD were adopted for exploring the mechanism of the promoted anti-K-poisoning property of Ce/TiO 2 catalyst. The obtained results demonstrated that Ce/TiO 2 with the addition of Zr exhibited larger specific surface area, higher dispersion of Ce species, higher redox property and more acid sites. As a result, the factors mentioned above could efficiently enhance the K tolerance of Ce/TiO 2 catalyst. By virtue of the in situ DRIFT analysis, the SCR reaction over Ce/TiZrO x catalyst was accelerated via Langmuir-Hinshelwood (L-H) mechanism. [ABSTRACT FROM AUTHOR]

Ammonia selective catalytic reduction (NH 3 -SCR) of nitrogen oxides is an effective and well-established technology for NO x removal, but current commercial denitrification catalysts based on V 2 O 5 -WO 3 /TiO 2 have some obvious disadvantages, including narrow operating temperature windows, toxicity, poor hydrothermal stability, and unsatisfied SO 2 /H 2 O tolerance. To overcome these drawbacks, it is imperative to investigate new types of highly efficient catalysts. In order to design catalysts with outstanding selectivity, activity, and anti-poisoning ability, core-shell structured materials have been widely applied in the NH 3 -SCR reaction, which exhibits numerous advantages including the large surface area, the strong synergy interaction of core-shell materials, the confinement effect, and the shielding effect from the shell layer to protect the core. This review summarizes recent developments of core-shell structured catalysts for NH 3 -SCR, including basic classification, synthesis methods, and a detailed description of the performance and mechanisms of each type of catalyst. It is hoped that the review will stimulate future developments in NH 3 -SCR technology, leading to novel catalyst designs with improved denitrification performance. [Display omitted] • Core-shell structured materials have been widely applied in the NH 3 -SCR reaction. • Core-shell structured SCR catalyst shows high catalytic activity. • Core-shell structure could protect the active components from deactivation. [ABSTRACT FROM AUTHOR]

Fe was used as the modifier to improve the performance of CeZr2Ox catalyst for the selective catalytic reduction (SCR) reaction with ammonia. Experimental results revealed that proper Fe species (Fe/Ce molar ratio = 2) could effectively improve the SCR activity of CeZr2Ox, along with the elevated resistance to SO2 and H2O. The characterization results including BET, XRD, H2-TPR and NH3-TPD confirmed that Fe species in Fe2CeZr2Ox catalyst could inhibit the formation of ZrO2 crystals and lead to higher reducibility and surface acidity. In addition, more Ce3+ and surface active oxygen species could be detected on Fe2CeZr2Ox compared with CeZr2Ox. By means of in situ DRIFT technique, it could be deduced that the SCR reaction process over Fe2CeZr2Ox was accelerated mainly through theL-H pathway due to the advanced adsorption of NH3 and NOx species, along with the promoted NO conversion to NO2. Therefore, the modification of CeZrOx catalyst by Fe had a significant stimulation effect on its low-temperature SCR performance. [ABSTRACT FROM AUTHOR]

The deactivation of SCR catalyst caused by K species contained in the fly ash would suppress its DeNOx performance. In this study, it was manifested that the modification of Ce/TiO 2 catalyst with P could enhance its K tolerance. To understand the promotion mechanism, the fresh and poisoned catalyst samples were subjected to the characterization techniques including BET, XRD, XPS, H 2 -TPR, NH 3 -TPD and in situ DRIFT. The results elucidated that the introduction of P species could increase the reducibility of Ce species and generate more surface chemisorbed oxygen, along with the strengthened surface acidity for NH 3 adsorption. It seemed that the NH 3 -SCR reaction mechanism over Ce/TiO 2 catalyst was a combination of L-H mechanism (<200 °C) and E-R mechanism (≥200 °C). After the addition of P species, the NO oxidation over Ce/TiO 2 catalyst was also accelerated, accompanied by the broadened temperature window for the NH 3 -SCR reaction under the control of L-H mechanism. The promoted NH 3 species adsorption and the generated more NO 2 over P-Ce/TiO 2 catalyst were conducive to the NH 3 -SCR reaction through L-H pathway, which might be the primary reason for its good K resistance. [ABSTRACT FROM AUTHOR]

[Display omitted] • CeSm/TiO 2 catalyst exhibits high low-temperature SCR activity. • The SCR reaction over CeSm/TiO 2 catalyst was controlled by L-H mechanism (<200 °C). • The promoted NO oxidation and NH3 adsorption are mainly responsible for the excellent performance of CeSm/TiO 2 catalyst. CeSmOx mixed oxide catalysts supported on TiO 2 prepared by coprecipitation method were used for selective catalytic reduction of NOx with NH 3. The results showed that the addition of Sm could effectively enhance the low-temperature SCR activity and SO 2 /H 2 O resistance of Ce/TiO 2 catalyst, and the appropriate mole ratio of Sm to Ce was 0.3. Characterization results indicated that the introduction of Sm could promote the formation of Ce3+ and chemisorbed oxygen species on catalyst surface, which was favorable to the generation of NO 2. Moreover, the doping of Sm could also promote the adsorption of NH 3 and NOx species on Ce/TiO 2 catalyst. The results of in situ DRIFT study revealed that the NH 3 -SCR reaction over CeSm/TiO 2 -0.3 catalyst was mainly controlled by the Langmuir−Hinshelwood mechanism in the low temperature range (<200 °C). Thereafter, the promoted NO oxidation and the enhanced NH 3 adsorption should play a major role for the excellent low-temperature SCR performance of CeSm/TiO 2 -0.3 catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nb modification can promote the adsorption of reactants on CuCeO x catalyst. • The SCR reaction on CuCeNbO x -0.4 catalyst mainly follows the L-H and E-R mechanisms. • The formed dual redox cycle on CuCeNbO x -0.4 catalyst favors the low-temperature SCR reaction. CuCeO x and CuCeNbO x - k with different Nb doping ratios were obtained by the citric acid method and applied in NH 3 -SCR process. The activity test results elucidated that the addition of Nb effectively ameliorated the low-temperature SCR performance. Among them, CuCeNbO x -0.4 catalyst had the finest SCR activity (more than 90% in 185–370 °C), highest N 2 selectivity, excellent SO 2 &H 2 O resistance and thermal stability. Numerous characterization analysis demonstrated that CuCeNbO x -0.4 had the largest specific surface area, the strongest surface acidity and the most excellent redox properties. The conclusions of in situ DRIFT manifested the Nb modification generated more activated species, enhanced the reactivity of ad-NH 3 and ad-NO x species, and the SCR reaction on CuCeNbO x -0.4 mainly followed the Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanisms. Furthermore, the Nb doping also formed the dual redox cycle (Cu2+ + Nb4+ ↔ Cu+ + Nb5+, Cu2+ + Ce3+ ↔ Cu+ + Ce4+), which facilitated the low-temperature SCR reaction. [ABSTRACT FROM AUTHOR]

• The chemical deactivation mechanisms of Mn-based SCR catalysts are analyzed. • The methods for improving the poisoning resistance of Mn-based SCR catalysts are discussed. • The regeneration of manganese-based SCR catalysts are probed. As a high-performance technology currently developed, selective catalytic reduction (SCR) of NO x with NH 3 has been universally employed to remove NO x from stationary sources. The traditional applied V 2 O 5 -based catalysts are proverbially applicable for medium-temperature range but unsuitable for NH 3 -SCR operated in the low-temperature conditions. Through massive research of theory and experiments, low-temperature NH 3 -SCR has drawn substantial attention due to the extensive demand for industrial furnaces and their energy-saving characteristics. During the past few years, Mn-based catalysts have been extensively investigated in NH 3 -SCR reaction for their high catalytic activity at low temperatures. In this paper, the deactivation mechanisms of SO 2 , H 2 O, alkali/alkaline earth metals (K, Na, Ca), and heavy metals (As, Pb, etc.) over Mn-based catalysts are discussed in detail. This review summarizes the methods to improve the anti poisoning of manganese-based catalysts, such as specific preparation methods, adding active components, doping additions and carrier modification, etc. Finally, different regeneration methods of poisoning caused by various poisons were analyzed and compared The obtained results can help researchers provide insight into the optimization of Mn-based SCR catalysts. [ABSTRACT FROM AUTHOR]

• Cs x WO 3 /g-C 3 N 4 catalyst shows full spectrum CO 2 photoreduction activity. • Improved charge separation efficiency is realized on Cs x WO 3 /g-C 3 N 4 catalyst. • LSPR effect is responsible for the NIR photocatalytic activity. Full spectrum-driven Cs x WO 3 /g-C 3 N 4 catalyst was successfully synthesized by the combination of solvothermal and ultrasonication methods and used in CO 2 photocatalytic reduction. The experimental results suggested that 20 wt% Cs x WO 3 /g-C 3 N 4 catalyst possessed the best yield of CH 4 under NIR and full spectrum light irradiation, which were 1.72 and 6.79 μmol·g−1·h−1, respectively. This outstanding photocatalytic activity could be attributed to the localized surface plasmonic resonance effect and the formation of heterojunction structure, which led to the improved charge separation efficiency, good light-harvesting ability and broadened light response. [ABSTRACT FROM AUTHOR]

Catalytic oxidation is a promising technique to control the emission of gaseous pollutants. Three-dimensionally ordered macroporous (3DOM)-based catalysts have aroused widespread attention because of their high porosity, large surface area and pore volume, superb ability of mass transfer. Therefore, they have been widely used in gaseous pollutants control field, such as soot and methane catalytic combustion, VOCs catalytic oxidation, photocatalytic CO 2 reduction and so on. In this review, the recent studies about the preparation and applications of 3DOM catalysts are summarized. At the same time, the advantages and mechanism of the 3DOM catalysts used in gaseous pollutants control are introduced in depth. Finally, the perspective and future direction of 3DOM-based catalysts for gaseous pollutants control are proposed. Image 1 • 3DOM-based catalysts are of high porosity, large surface area and pore volume. • Excellent mass transfer is available on 3DOM-based catalysts. • 3DOM catalysts for gaseous pollutants abatement are summarized. [ABSTRACT FROM AUTHOR]

• MnCrO x -UL shows superior NH 3 -SCR performance and high resistance to SO 2. • More ad-NH 3 and ad-NO x species are available on the surface of MnCrO x -UL. • The ad-NH 3 and ad-NO x species over MnCrO x -UL are of higher reactivity. A novel urchin-like catalyst (MnCrO x -UL) was successfully synthesized by hydrothermal redox reaction. In addition, a reference sample (MnCrO x) was prepared by co-precipitation process for comparison. Experimental results revealed that MnCrO x -UL showed superior NH 3 -SCR performance in the temperature range of 150–350 °C and high resistance to SO 2. The results of characterization demonstrated that MnCrO x -UL showed larger surface area, more acidic sites, higher redox capacity and more oxygen vacancies compared with MnCrO x. Additionally, more activated adsorbed species over MnCrO x -UL sample surface could also effectively improve the NH 3 -SCR performance at low temperature. [ABSTRACT FROM AUTHOR]