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• Ruthenium nanoparticles supported on gallium-modified molecular sieve applied for generating hydrogen from its hydride ammonia via its photothermal decomposition. • The thermal effect of light enhanced the efficiency of the reaction much more than heating. • Natural light in the photothermal synergistic catalysis is sustainable and economical. Because the high electron cloud density around Ru is favorable for ammonia decomposition, gallium addition to it resulted in an alkaline molecular sieve carrier with a large specific surface area. It was revealed that GaOH not only elevated the electron cloud density near the active center of Ru but also encouraged N H bond breaking and hydrogen atoms' binding on the catalyst surface. Furthermore, the molecular sieve's regular pore structure strongly inhibited the growth of Ru particles within it, resulting in a high degree of mono-dispersion of Ru nanoparticles and a reduction in the average particle size of the Ru active center to < 3 nm. For TOF >1, the above two factors combined to decrease the ammonia decomposition temperature to < 450 °C. Furthermore, under photothermal synergistic catalysis, the hydrogen production rate via ammonia decomposition was further elevated, and the reaction temperature was further decreased to < 380 °C with TOF > 1. In situ UV photoelectron spectroscopy clarified that the hydrogen atom concentration on Ru increased during photothermal catalysis. According to the FT-IR analysis of the surface intermediate of NH/NH 2 formed by ammonia decomposition, photothermal synergistic catalysis can weaken the N H bond compared with pure heating, making it easier for H atoms to combine and form H 2. The test results of the correlation between activation energy, reaction rate, and ammonia partial pressure show that, when compared to pure thermal catalysis, photothermal catalysis does not substantially alter the reaction path. The primary reason behind the increased hydrogen production rate of ammonia decomposition by photothermal catalysis was the thermal effect of the light source. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Introduction of WO 3 promoted N 2 selectivity and broadened temperature window. • Novel assembly strategy " acidity u & redox d " balanced activity and N 2 selectivity. • Doping WO 3 changed the reaction mechanism that promoted NH 3 /inhibited NO adsorption. • Doping rare earth elements improved redox ability and low temperature activity. • The modified acid zeolite-like montmorillonite is an efficient SCR catalyst support. It is still a challenge for de-NO x catalysts to have high activity and N 2 selectivity in a wide low-temperature operating temperature window. In this work, we used layered zeolite-like montmorillonite as the support and then obtained a composite catalyst with satisfactory NO x conversion and excellent N 2 selectivity in the temperature range of 100–300 °C with the method of pillaring modification, active component doping, and catalyst assembly. It has been proved that doping rare earth elements can improve the redox ability of the catalyst, and WO 3 modification can enhance the acidity of the catalyst. The redox ability and the surface acidity of the catalyst system were balanced by assembling the WO 3 -modified catalyst and the WO 3 -unmodified catalyst. Besides, we found the composite Pr 1 Mn 9 /Fe 7 Ti 3 -W u -mmt catalyst had the best catalytic activity and N 2 selectivity only when the reaction gas first passed through the catalyst modified by WO 3 , in which the WO 3 -modified catalyst acted as the role of nitrous oxide filter. What's more, according to the results of in situ DRIFTS, it can be indicated that the montmorillonite-supported catalysts in this work followed the L-H mechanism and E-R mechanism; while the E-R mechanism was dominant when the catalyst was modified by WO 3. The results in present work indicate that the novel strategy of assembling catalysts is practicable to obtain an efficient de-NO x catalyst with a wide low-temperature operating temperature window, high NO x conversion, and high N 2 selectivity. Furthermore, the novel assembly strategy of tandem catalysis with stronger acidity sites and redox sites in turn " acidity u & redox d " can be extended to other SCR catalytic systems. [ABSTRACT FROM AUTHOR]

Abstract: Two kinds of Co3O4 samples with micro/nano-structure as high capacity anode materials for Lithium-ion Batteries are synthesized by a facile method. The structure, composition and surface morphology are analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), respectively. The XRD data indicates that the two Co3O4 materials are crystalline, single-phase without any impurity phase; the size of spheres and cubes are estimated to be 2 μm and the nanoparticles are around 100 nm. The cyclic voltammetry and discharge/charge measurements are carried out to detect the electrochemical properties. The results demonstrate that the two Co3O4 electrodes with micro/nano-structure exhibit low initial irreversible capacity and superior cycling performance. The two Co3O4 materials with micro/nano-structure are confirmed to combine the advantages of the micro-materials and nano-materials for LIBs. Moreover, the Co3O4 spheres (s-Co3O4) exhibit more superior cycling performance than that of Co3O4 cubes (c-Co3O4) due to the larger void volume in spheres than that in cubes structure. [Copyright &y& Elsevier]

Abstract: Au@Pd core–shell nanoparticles (NPs) were synthesized using seed-mediated method, and three samples with different shell structures were obtained by tuning the Au core size. The shape-dependent catalytic activities of Au@Pd core–shell NPs toward ethanol oxidation in alkaline electrolytes were systematically explored. The electrochemical experiments showed that the Au@Pd-2 core–shell NPs (with Au core size of 9.8nm and loose Pd shell) exhibited a distinctly higher activity and poison-resistance for the ethanol oxidation than other core–shell structures. Based on the Au@Pd-2 core–shell NPs and Pd NPs, two amperometric ethanol gas sensors were fabricated. During the sensor tests, the ethanol sensor based on Au@Pd-2 NPs showed good performance for ethanol in the range of 50–600ppm with sensitivity of 178.5nAppm−1 and less than 5% signal loss in 60 days. [Copyright &y& Elsevier]

Vapor-phase dehydration of glycerol to produce acrolein was investigated at 320 °C over rare earth (including La, Ce, Nd, Sm, Eu, Gd, Tb, Ho, Er, Tm, Yb, Lu) pyrophosphates, which were prepared by precipitation method. The most promising catalysts were characterized by means of XRD, FT-IR, TG-DTA, BET and NH3-TPD measurements. The excellent catalytic performance of rare earth pyrophosphate depends on the appropriate surface acidity which can be obtained by the control of pH value in the precipitation and the calcination temperature, e.g. Nd4(P2O7)3 precipitated at pH = 6 and calcined at 500 °C in the catalyst preparation. [ABSTRACT FROM AUTHOR]

Abstract: Liquid phase oxidation of cyclohexane was carried out under mild reaction condition over copper pyrophosphate catalyst in CH3CN using hydrogen peroxide as an oxidant at the temperature between 25 and 80°C. The copper pyrophosphate catalyst was characterized by means of XRD, FT-IR and water contact angle measurement. It was found that appropriate surface hydrophobicity is the key factor for the excellent performance of the catalyst. In addition, a significant improvement for the cyclohexane conversion in the presence of organic acid was observed. [Copyright &y& Elsevier]

Abstract: It is discovered that SBA-15 (santa barbara amorphous) can provide the favorable microenvironments and optimal direct electron-transfer tunnels (DETT) of immobilizing cytochrome c (Cyt c) by the preferred orientation on it. A high-redox potential (254mV vs. Ag/AgCl) was obtained on glassy carbon (GC) electrode modified by immobilizing Cyt c on rod-like SBA-15. With ultraviolet–visible (UV–vis), circular dichroism (CD), FTIR and cyclic voltammetry, it was demonstrated that immobilization made Cyt c exhibits stable and ideal electrochemical characteristics while the biological activity of immobilized Cyt c is retained as usual. The electrochemistry behavior at the modified GC electrode is surface-controlled quasi-reversible process with an enhanced electron-transfer rate constant of 2.20s−1 because of the optimal DETT between Cyt c and SBA-15. It was also found that the modified GC electrode exhibited a predominant electrocatalytic activity for the reduction of hydrogen peroxide, which may open up a possibility for designing and fabricating enzyme electrodes with application potentials in biosensor and biofuel cells. [Copyright &y& Elsevier]

Abstract: Arabinogalactan derivatives conjugated with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) by ethylenediamine (Gd-DTPA-CMAG-A2) or hexylamine (Gd-DTPA-CMAG-A6) have been synthesized and characterized by means of Fourier transform infrared spectra (FTIR), 13C nuclear magnetic resonance (13C NMR), size exclusion chromatography (SEC), and inductively coupled plasma atomic emission spectrometry (ICP-AES). Relaxivity studies showed that arabinogalactan-bound complexes possessed higher relaxation effectiveness compared with the clinically used Gd-DTPA, and the influence of the spacer arm lengths on the T 1 relaxivities was studied. Their stability was investigated by competition study with Ca2+, EDTA, and DTPA. MR imaging of Wistar rats showed remarkable enhancement in rat liver and kidney after i.v. injection of Gd-DTPA-CMAG-A2 (0.079±0.002mmol/kg Gd3+): The mean percentage enhancement of the liver parenchyma and kidney was 38.7±6.4% and 69.4±4.4% at 10–30min. Our preliminary in vivo and in vitro study indicates that the arabinogalactan-bound complexes are potential liver-specific contrast agents for MRI. [Copyright &y& Elsevier]

Abstract: The reaction mechanism of the Beckmann rearrangement over B2O3/γ-Al2O3 and TS-1 in the gas phase has been investigated by isotope labeling approach. The isotopic labeled products were measured by mass spectrometry method. By exchanging oxygen with H2 18O in the rearrangement step, it was found that the exchange reaction between cyclohexanone oxime and H2 18O over B2O3/γ-Al2O3 and TS-1 could only be carried out in some extent. It suggested that the dissociation of nitrilium over solid acids be not completely free as the classical mechanism. A concept of the dissociation degree (α) that is defined as the ratio of the dissociated intermediate nitrilium to the total intermediate nitrilium has been proposed. By fitting the experimental values with the calculation equation of isotopic labeled products, it is obtained that α values for B2O3/γ-Al2O3 and TS-1 are 0.199 and 0.806 at the reaction conditions, respectively. [Copyright &y& Elsevier]

Abstract: Fe–Ni–O samples, with Fe/Ni ratio ranging from 2 to 1/3, were synthesized. Samples synthesized with and without citric acid in the precursor were compared and it was found that the addition of citric acid is the necessary condition for FeNi3 formation; it was found that FeNi3 alloys were formed in these samples even when calcined in an air atmosphere. X-ray diffraction and X-ray photoelectron spectroscopy measurements were used to characterize the samples. Because of the existence of FeNi3 alloys, Fe–Ni–O samples showed strong reactivity to NO and NO+O2 but were inert to O2 alone. [Copyright &y& Elsevier]

Abstract: Compound of La2−x Sr x CuO4 (x ≥0.5) with T* phase structure were prepared by conventional citric method. The split peak at 2θ =∼31° in XRD patterns and the broad absorption band at 680cm−1 with a shoulder peak at 620cm−1 in IR spectra suggested the formation of T* phase in La2−x Sr x CuO4 compounds at x ≥0.5. The amount of sample with T* phase structure increased with the increase of Sr content as certified by XRD patterns. Catalytic performance of La2−x Sr x CuO4 for NO decomposition was investigated, and it was found, by correlating the solid-state properties and the activity of NO decomposition, that the presence of T* phase structure enhanced the catalytic activity of La2−x Sr x CuO4 in NO decomposition. [Copyright &y& Elsevier]

Abstract: Catalytic reduction of NO by CO was studied over perovskite-like La2−x Sr x CuO4 (x =0.0, 0.5, 1.0) catalysts prepared by citrate method and calcined at 900°C. The catalysts were characterized by O2-TPD, H2-TPR and cyclic voltammetry (CV) measurements. Results obtained from CV were in well agreement with those obtained from O2-TPD and H2-TPR, suggesting that CV is also a powerful means in the study of heterogeneous catalytic reaction carried out at high temperatures. In O2-TPD experiment, the desorption area of β oxygen, which was contributed by the oxygen adsorbed on the oxygen vacancy, increased with the increase of Sr content and was in the same order as the activity, indicating that the activity depended largely on the oxygen vacancy resulted by Sr addition. In H2-TPR measurements, the increasing area of the first reduction peak indicating that the oxygen vacancy resulted by Sr addition plays important role in this peak, since the Cu3+ content in La1.5Sro.5CuO4 and LaSrCuO4 is the same. And in the CV curves, the area of redox peak, which represents the amount of oxygen vacancy participating in the reaction, has close correlations with the activity of NO+CO reaction, while the symmetry of redox potentials does not contribute much to the activity. Overall, with the link of oxygen vacancy, CV was introduced and has obtained great success in explaining reaction in heterogeneous catalysis. Besides, from the result that none reductive peak was observed in the first CV curves of LaSrCuO4, it suggested that the first step of a catalytic reaction is reduction, corresponding to the oxidation of catalyst i.e., M n+(Cu2+)→M(n+1)+(Cu3+). [Copyright &y& Elsevier]

Abstract: Perovskite-type oxide La0.4Sr.6Mn0.8Ni0.2O3 showed high activity for NO decomposition and thus was taken as the catalyst for investigation. Based on the ‘recycle’ mechanism of NO decomposition (NO2 acts as an intermediate of O2 formation) we reported recently, the kinetics of NO decomposition over La0.4Sr.6Mn0.8Ni0.2O3 was investigated. The NO decomposition rate was practically first-order for NO in the range 0.5–2.0vol.% NO/He, while the reaction order varied from −0.24 to −0.08 for O2 (0–6vol.% O2/He), depending on the temperature. The kinetics deduced from the ‘recycle’ mechanism accords well with that observed in practice by introducing the item K −6 (K −7)1/2 P NO ()1/2, which reflects the reciprocity of O2 and NO in the reaction and is introduced in the kinetics for the first time. The rates and NO2 dissociation equilibrium constants calculated from the practical reaction certified that NO2 dissociation is indeed an important step of NO decomposition, and hence suggested that the ‘recycle’ mechanism is believable. [Copyright &y& Elsevier]

Abstract: Effect of cerium ions on the activity of La1−x Ce x SrNiO4 (0≤ x ≤0.3) for NO decomposition was investigated both in the absence and presence of oxygen. The amount of Ce in the frame reached 30at.% (x =0.3) in the present case without destroying the matrix structure. The Ce-substituted samples showed high activity for NO decomposition not only in the absence of O2 but also in the presence of O2, and the specific activity reached 1.59μmols−1 m−2 even 6.0%O2 was fed to the reactant gas (La0.7Ce0.3SrNiO4, T =1123K), indicating that the Ce addition can enhance the oxygen forbearance of catalyst. In addition, a new highly active site, which facilitates oxygen mobilization and desorption, might be formed in the sample due to the Ce addition, which thus resulted in the high activity for NO decomposition. [Copyright &y& Elsevier]

Abstract: Mechanism of NO decomposition over perovskite(-like) oxides was explored through investigating the experiments of O2-TPD and the activity of NO decomposition. It was found that the mechanism of NO decomposition over perovskite(-like) oxides was performed in a ‘recycle’ way, in which the recycle of NO2 (its formation and dissociation) plays an important role in the reaction and relates greatly with the activity. Because NO2 dissociation reaction (2NO2 =2NO+O2) is an important step in the process of NO decomposition, catalytic activity of NO decomposition over perovskite(-like) mixed oxides achieved only at high temperatures, at which the NO2 dissociation reaction occurs. [Copyright &y& Elsevier]

Discusses the process of nitric oxide (NO) decomposition on perovskite-like catalysts. NO decomposition reaction; Thermodynamic equilibrium; Activity of NO decomposition as a function of oxygen partial pressure; Importance of oxygen vacancy for NO decomposition.

The improvement of stability is a crucial and challenging issue for industrial catalyst, which affects not only the service time but also the cost of catalyst. This is especially prominent for that applied in harsh environment atmospheres, such as the exhaust of diesel vehicles. Herein, we reported a new strategy to improve the high-temperature hydrothermal stability of Cu-SSZ-13, which is a promising catalyst for the treatment of exhaust emitted from diesel vehicles through the NH 3 -SCR NO x route. Different from that reported in literature, we managed to improve the high-temperature hydrothermal stability of Cu-SSZ-13 by coating the surface with a nanolayer of stable SiO 2 material using the atomic layer deposition (ALD) method. The coating of SiO 2 layers effectively suppressed the leaching of alumina from the SSZ-13 molecular sieve even after the hydrothermal aging at 800 °C for 16 h with 12.5% water in air. Meanwhile, the ultra-thin SiO 2 nanolayer does not block the pores of zeolites and affect the catalytic activity of Cu-SSZ-13 contribute to the superiority of the ALD technology. [Display omitted] • Atomic layer deposition (ALD) was introduced to coat several nanometer layers SiO 2 on the surface of Cu-SSZ-13. • The high temperature hydrothermal aging resistant at 800 °C with 12.5% water in air is improved by the SiO 2 nanolayer. • The SiO 2 nanolayer can relieve the Cu2+ migration, dealuminization and frameworks collapse during the aging treatment. • The acidity and redox properties of Cu-SSZ-13 can be effectively maintained by the SiO 2 nanolayer. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction of NO x with CO (CO-SCR) is a process that purifies both NO and CO pollutants through a catalytic reaction. Specifically, the cleavage of NO on the catalyst surface is crucial for promoting the reaction. During the reaction, the presence of oxygen vacancies can extract oxygen from NO, thereby facilitating the cleavage of NO on the catalyst surface. Thus, the formation of oxygen vacancies is key to accelerating the CO-SCR reaction, with different types of oxygen vacancies being more conducive to their generation. In this study, Rh/CeCuO x catalysts were synthesized using the co-crystallization and impregnation methods, and asymmetric oxygen vacancies were induced through hydrogen thermal treatment. This structural modification was aimed at regulating the behavior of NO on the catalyst surface. The Rh/Ce 0.95 Cu 0.05 O x -H 2 catalyst exhibited the best performance in CO-SCR, achieving above 90% NO conversion at 162 °C. Various characterization techniques showed that the H 2 treatment effectively reduced some of the CuO and Rh 2 O 3 , creating asymmetric oxygen vacancies that accelerated the cleavage of NO on the catalyst surface, rather than forming difficult-to-decompose nitrates. This study offers a novel approach to constructing oxygen vacancies in new CO-SCR catalysts., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Modifying the local fields of active metals can directly and effectively optimize the catalytic performance in the heterogeneous catalytic process. Here, the local fields of single-atom Pd in the Pd 1 /CeO 2 catalyst were tailored by using a self-sacrificial electron-rich carbon nitride to obtain the Pd 1 O 4 Ce 2 /CeO 2 with coordination unsaturated single-atom Pd. Compared with Pd 1 O 4 Ce 3 /CeO 2 with coordination saturated single-atom Pd, the Pd 1 O 4 Ce 2 /CeO 2 catalyst showed enhanced activity for CH 4 combustion with decreased 118 °C of T 50 and 8 times higher in turnover frequency (TOF) at 400 °C. The thermal decomposition of carbon nitride pre-coordinated Pd created a unique atmosphere around Pd species, leading to the formation of coordination unsaturated single-atom Pd on the surface of CeO 2 . This coordination unsaturated single-atom Pd catalyst conduced to the polarization of CH 4 and reduced the cleavage energy barrier of CH 4 , thus accelerating the catalytic activity. The construction method of this coordination unsaturated structure provides insights for the designing and synthesizing of highly active single atom catalysts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025. Published by Elsevier Inc.)

V 2 O 5 -WO 3 /TiO 2 (VWTi) catalyst has long been utilized in fixed source flue gases to purify harmful NO gas. However, VWTi is classified as a hazardous material because of its harm to human health and environment. To address this issue, a low-cost green Cu-based zeolite catalyst (Cu@13X) with a wide temperature range was synthesized using an in-situ hydrothermal method. This method is intended to control the adsorption capacity of toxic SO 2 by regulating the location of Cu species. UV-Vis DRS and EXAFS analyses revealed that a significant amount of Cu was encapsulated within the 12-membered ring pores of the 13X molecular sieve. SO 2 -TPD and DFT calculations further indicated that Cu@ 13X exhibits reduced SO 2 chemical adsorption capacity. Consequently, this green catalyst demonstrated superior catalytic performance, maintaining superior NO x conversion for over 70 h in the mixture gas containing 250 ppm SO 2 ; while the Cu/13X catalyst lacked NH 3 -SCR catalytic activity under the same conditions. Moreover, Cu@ 13X catalyst also has excellent NH 3 -SCR catalytic performance in low temperature flue gas below 250 °C, which is significantly better than the hazardous VWTi catalyst. Characterization techniques such as NH 3 -TPD, H 2 -TPR, and XPS confirmed that the Cu@ 13X catalyst possesses excellent acidity, robust redox capabilities, and abundant surface defects. In-situ DRIFT spectra further illustrated that the NH 3 -SCR reaction on the catalyst surface adheres to the Eley-Rideal mechanism both before and after the introduction of toxic SO 2 . This study offers a fresh perspective on the development of framework-confined NH 3 -SCR catalysts and elucidates the mechanism behind the sulfur resistance of these catalysts. And the green Cu@ 13X catalyst is anticipated to serve as an effective alternative to the hazardous VWTi catalyst., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Human society is facing increasingly serious problems of environmental pollution and energy shortage, and up to now, achieving high NH 3 -SCR activity at ultra-low temperatures (<150 °C) remains challenging for the V-based catalysts with V content below 2%. In this study, the monoatomic V-based catalyst under the weak current-assisted strategy can completely convert NO x into N 2 at ultra-low temperature with V content of 1.36%, which shows the preeminent turnover frequencies (TOF 145 °C  = 1.97×10 -3  s -1 ). The improvement of catalytic performance is mainly attributed to the enhancement catalysis of weak current (ECWC) rather than electric field, which significantly reduce the energy consumption of the catalytic system by more than 90%. The further mechanism research for the ECWC based on a series of weak current-assisted characterization means and DFT calculations confirms that migrated electrons mainly concentrate around the V single atoms and increase the proportion of antibonding orbitals, which make the V-O chemical bond weaker (electron scissors effect) and thus accelerate oxygen circulation. The novel current-assisted catalysis in the present work can potentially apply to other environmental and energy fields., (© 2024. The Author(s).)

It is essential to develop the catalyst for NH 3 -SCR with excellent performance at ultra-low temperature (≤150 °C), and resource recycling is another important part of environmental protection. Based on the principle of environmental friendliness, the LiMn 2 O 4 , one of the waste battery cathode materials, was successfully modified into a novel high-value catalyst for ultra-low temperature NH 3 -SCR through hydrogen ion exchange and two-dimensional vanadic oxide modification. The optimized LiMn 2 O 4 -0.5V-10H catalyst performed the best balance of NO x conversion and N 2 selectivity, with activity reaching 96 % at 150 °C and N 2 selectivity exceeding 70 % at ultra-low temperature. Due to the unique three-dimensional network structural characteristics of LiMn 2 O 4 spinel, hydrogen exchange could exchange Li + from the lattice and increase surface acidity; and a small amount of two-dimensional vanadic oxide loading could appropriately regulate redox ability and increase acidic sites. The in-situ DRIFTS results still showed that the L-H and E-R mechanisms coexisted during the reaction. Moreover, combining first-principles calculations and in-situ DRIFTS, the dual modification of H and V could enhance the adsorption of NH 3 on the surface of LiMn 2 O 4 but weaken the adsorption of NO, and promote the decomposition of nitrites while inhibit the formation of surface nitrate species, which was the core reason for the improvement of N 2 selectivity. The modification mode in this work was simple and inexpensive, which provided a new idea for the high-value utilization of waste batteries and the design of NO x purification catalyst at ultra-low temperature., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Modulating the Rh active sites on surfaces of Al 2 O 3 is crucial to developing effective three-way catalysts. Herein, an ultralow amount of ZrO 2 (0.0179%) was deposited onto Al 2 O 3 nanorods via atomic layer deposition (ALD) to form a catalyst with both thermal stability and low-temperature activity. The results demonstrate that the ALD-ZrO 2 is conducive to improve the catalytic activity of the Rh site and inhibit the formation of irreducible Rh species at high temperature. The obtained catalysts show satisfactory performance for a model NO-CO reaction even after thermal aging at 1050 °C. This strategy shows that a molecularly precise synthesis can lead to the robust promotion of Rh activity under low temperature and provide a promising path toward reducing the deactivation of catalysts at high temperature.

Pt-Ni nanoframes (Pt-Ni NFs) exhibit outstanding catalytic properties for several reactions owing to the large numbers of exposed surface active sites, but its stability and selectivity need to be improved. Herein, an in situ method for construction of a core-shell structured Pt-Ni NF@Ni-MOF-74 is reported using Pt-Ni rhombic dodecahedral as self-sacrificial template. The obtained sample exhibits not only 100 % conversion for the selective hydrogenation of p-nitrostyrene to p-aminostyrene conducted at room temperature, but also good selectivity (92 %) and high stability (no activity loss after fifteen runs) during the reaction. This is attributed to the Ni-MOF-74 shell in situ formed in the preparation process, which can stabilize the evolved Pt-Ni NF and donate electrons to the Pt metals that facilitate the preferential adsorption of electrophilic NO 2 group. This study opens up new vistas for the design of highly active, selective, and stable noble-metal-containing materials for selective hydrogenation reactions., (© 2020 Wiley-VCH GmbH.)

The MO x (M = Cu, Mn, Co)/CePO 4 support was firstly prepared via the hydrothermal and impregnated method. Selective catalytic reduction of NO with NH 3 (NH 3 -SCR) results showed that the MnO x modifications greatly improved the SCR activities at low temperatures. The NOx conversion of the MnO x /CePO 4 catalyst was above 80% even at 180 °C. In-situ DRIFTS results suggest that the SCR reaction is majorly conducted between the absorbed monodentate nitrate and NH 3 species (i.e., the Langmuir-Hinshelwood mechanism). MOx (M = Cu, Mn, Co) exists in the formation of nano-size particles obtained by SEM and TEM directly. These nano-size particles can provide active surface adsorbed oxygen and thus improve the NO oxidation ability as indicated by the O 2 -TPD and NO oxidation tests. The process of NO oxidation to NO 2 plays a key role to produce the absorbed monodentate nitrate as indicated by the In-situ DRIFTS. The support CePO 4 acts as the acid sites to form highly active NH 4 + species. The synergic effect between the MnO x and CePO 4 contributed to the high SCR activity over the MnO x /CePO 4 catalyst. Additionally, the MOx/CePO 4 catalyst exhibits an excellent water tolerance and N 2 selectivity. Consequently, the MnO x /CePO 4 catalyst becomes the potential catalyst for the practical process., (Copyright © 2018 Elsevier B.V. All rights reserved.)

By integrating redox self-assembly and redox etching processes, we report a general one-pot strategy for the synthesis of Au@multi-M x O y (M = Co, Ce, Fe, and Sn) yolk@shell nanospheres. Without any additional protecting molecule or reductant, the whole reaction is a clean redox process that happens among the inorganic metal salts in an alkaline aqueous solution. By using this method, Au@Co 3 O 4 /CeO 2 (Au@Co-Ce), Au@Co 3 O 4 /Fe 2 O 3 (Au@Co-Fe), and Au@CeO 2 /SnO 2 (Au@Ce-Sn) yolk@shell nanospheres with binary oxides as shells, Au@Co 3 O 4 /CeO 2 /Fe 2 O 3 (Au@Co-Ce-Fe) yolk@shell nanospheres with ternary oxides as shells and Au@Co 3 O 4 /CeO 2 /Fe 2 O 3 /SnO 2 (Au@Co-Ce-Fe-Sn) yolk@shell nanospheres with quaternary oxides as shells can be obtained. Subsequently, the catalytic CO oxidation was selected as the catalytic model, and the Au@Co-Ce system was chosen as the catalyst. It was found that the catalytic activity of Au@Co-Ce yolk@shell nanospheres can be optimized by altering the relative proportion of Co and Ce oxides.