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The focus of this study, using results obtained with hollow specimens of the alloy Al 2024 T3 (AlCuMg2 T3) with a one‐sided bore, was to determine if, under multiaxial loading, the fatigue strength in a notch with a uniaxial stress state can simply be assessed without the application of any multiaxial strength hypothesis. In the fatigue critical location, the bore edge, only a superimposition of normal stress components, resulting from axial loading or/and torsion, occurs. In the case of out‐of‐phase loading, the resulting local uniaxial stress is even lower than the stress under in‐phase loading and leads to an increase of fatigue life to crack initiation under the non‐proportional loading, which is not observed in the case of multiaxial stressing/straining of the material itself. As the local stress state in the crack initiation site is uniaxial, the application of a multiaxial strength hypothesis, for the failure criterion of crack initiation (l=0.2 mm), is not necessary. Furthermore, the benefit of non‐homogenous stress distributions, which allow locally higher stresses than the levels given by the Woehler‐line for unnotched specimens, was underlined by considering highly‐stressed, material‐volume‐related support factors. [ABSTRACT FROM AUTHOR]

Strong support effect (SSE) has been regarded as one of the most important concepts in heterogeneous catalysis, which has been almost exclusively discussed in metal/oxide catalysts. Here, we report a new SSE paradigm with strong interfacial charge transfer between a series of metal sulfides and Ti 3 C 2 T x support, which results in sulfur vacancies (V S) formed in metal sulfides and enhanced photoactivity for CO 2 -to-CO conversion. [Display omitted] Selective CO 2 -to-CO photoreduction is under intensive research and requires photocatalysts with tuned microstructures to accelerate the reaction kinetics. Here, we report CuInS 2 nanosheet arrays with sulfur vacancies (V S) grown on the two-dimensional (2D) support of Ti 3 C 2 T x MXene for CO 2 -to-CO photoreduction. Our results reveal that the use of Ti 3 C 2 T x induces strong support effect, which causes the hierarchical nanosheet arrays growth of CuInS 2 and simultaneously leads to charge transfer from CuInS 2 to Ti 3 C 2 T x support, resulting in V S formed in CuInS 2. The strong support effect based on Ti 3 C 2 T x is proven to be applicable to prepare a series of different metal indium sulfide arrays with V S. CuInS 2 nanosheet arrays with V S supported on Ti 3 C 2 T x benefit the photocatalytic selective reduction of CO 2 to CO, manifesting a remarkable over 14.8-fold activity enhancement compared with pure CuInS 2. The experimental and computational investigations pinpoint that V S of CuInS 2 resulting from the support effect of Ti 3 C 2 T x lowers the barrier of the rate-limiting step of *COOH → *OH + *CO, which is the key to the photoactivity enhancement. This work demonstrates MXene support effects and offers an effective approach to regulate the atomic microstructure of metal sulfides toward enhancing photocatalytic performance. [ABSTRACT FROM AUTHOR]

The Sanya estuary passage project is the latest and highly technical underground project after the large shield underground construction, which is of great significance to the construction of the Hainan free trade port and underground space construction innovation. In this paper, we use finite element software to analyze the deformation, stress, and surface settlement of the pipe curtain structure during construction under two conditions (original riverbed line and maximum scour riverbed line) in order to provide guidance for the actual project. Numerical simulations show that due to excavation and unloading, the bottom and top of the pipe curtain structure are subject to tensile stress; the bottom rises, the top settles, and converges in the horizontal direction; under the original riverbed line condition, the displacement values of each index are larger; changing the riverbed line does not change the maximum and minimum main stress of the pipe curtain structure significantly, and the stiffness of the pipe curtain structure can meet the maximum water level and the maximum scour in two unfavorable conditions; the pipe curtain structure can meet the structural. The pipe screen structure can meet the structural load‐bearing requirements. Suggestions for the design and construction of the project: strengthen the thickness of the pipe curtain at the side wall position, that is, use larger diameter steel pipes; do a good job of antiseepage and anticracking of the concrete at the corner of the pipe curtain structure and the side wall position during the construction process. [ABSTRACT FROM AUTHOR]

Colloidal solutions of gallia‐alumina (Ga,Al)2O3(x:y) solid‐solution nanoparticles with nominal atomic Ga : Al (x:y) ratios of 1 : 6, 1 : 3, 3 : 1, and 1:0 were used to prepare silica‐supported catalysts for propane dehydrogenation (PDH). A comparison of the unsupported and silica‐supported catalysts reveals that the dispersion on silica increases the Ga‐normalized PDH rates for all catalysts, albeit with a notably lower propene selectivity for (Ga,Al)2O3(1:6)/SiO2. Fourier transform infrared (FTIR) spectroscopy allows contrasting the H2 dissociation sites in the calcined and H2‐treated (Ga,Al)2O3(x:y)/SiO2, indicating a transformation of Ga3+ surface sites with Al (mainly) and Ga atoms in the second coordination sphere (Ga(Al/Ga) sites) in the calcined (Ga,Al)2O3(1:6)/SiO2 to predominantly Ga(Ga/Si) surface sites in the H2‐treated material. The resulting sites are similarly unselective as in amorphous gallia on silica. H2 produced during the PDH reaction can cause a similar transformation as H2 pretreatment in (Ga,Al)2O3(1:6)/SiO2, rapidly resulting in a notably lowered selectivity. The stable and selective Ga(Al/Ga) surface sites in (Ga,Al)2O3(1:3)/SiO2 yield a Ga−H band at ca. 1990 cm−1 under H2 dissociation conditions while the less selective surface sites, observed for the other Ga : Al ratios, give Ga−H bands at ca. 2040 and 2060 cm−1. [ABSTRACT FROM AUTHOR]

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office 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.)

Aqueous-phase reforming (APR) is an attractive process to produce bio-based hydrogen from waste biomass streams, during which the catalyst stability is often challenged due to the harsh reaction conditions. In this work, three Pt-based catalysts supported on C, AlO(OH), and ZrO2 were investigated for the APR of hydroxyacetone solution in a fixed bed reactor at 225 °C and 35 bar. Among them, the Pt/C catalyst showed the highest turnover frequency for H2 production (TOF of 8.9 molH2 molPt−1 min−1) and the longest catalyst stability. Over the AlO(OH) and ZrO2 supported Pt catalysts, the side reactions consuming H2, formation of coke, and Pt sintering result in a low H2 production and the fast catalyst deactivation. The proposed reaction pathways suggest that a promising APR catalyst should reform all oxygenates in the aqueous phase, minimize the hydrogenation of the oxygenates, maximize the WGS reaction, and inhibit the condensation and coking reactions for maximizing the hydrogen yield and a stable catalytic performance.

Steady-state, differential reaction rates for CO oxidation, with stoichiometric O2:CO feeds, were measured in the presence and absence of H2O over Pt catalysts supported on thin films of CeFeOx, FeOx, CeOx, and LaFeO3 that had been deposited on γ-Al2O3 by Atomic Layer Deposition. Prior to rate measurements, each catalyst was oxidized and reduced five times at 1073 K. Only the oxidized Pt/CeFeOx/γ-Al2O3 catalyst exhibited significantly increased CO oxidation rates upon the introduction of H2O. A relatively small deuterium isotope effect was observed and suggests that O–H bond cleavage is not involved in the kinetically relevant step of this process. The nature of the catalyst support, the pretreatment of the catalyst, and the effects of Pt particle size are discussed in relation to the observed H2O promotion of CO oxidation. [ABSTRACT FROM AUTHOR]

It is known that photocatalytic activity of Ga2O3 on CO2 reduction with water is enhanced by employment of a support. However, the role of the support is not understood well. We have investigated the roles of the support on the photocatalytic CO2 reduction with using Ga2O3 supported by Al2O3 and MgAl2O4 as catalysts. On the supports, loaded Ga2O3 exhibited different crystalline phases and morphologies depending on the amount of loaded Ga2O3 on the supports and the specific surface areas of the supports. The larger the SSA, the more dispersedly Ga2O3 particles were loaded and gave higher catalytic activity. The production rates of H2 and CO, the dominant products of the CO2 reduction, showed different crystalline phase dependence, i.e., H2 production was dominated on α-Ga2O3, while the CO production rate increased with increasing the γ-Ga2O3/α-Ga2O3 ratio and peaked at a certain γ-Ga2O3/α-Ga2O3 ratio. Two main conclusions derived are, (1) Ga2O3 particles dispersedly loaded as a few tens nm sized rods on the support significantly enhance the photocatalytic activity and (2) a new mechanism that on α-Ga2O3 water splitting is dominated and resultant H atoms reduce CO2 adsorbed on γ-Ga2O3 or the boundary of the two phases. [ABSTRACT FROM AUTHOR]

Supported Pd catalysts show superior activities for olefin productions from alkynes through semi-hydrogenation reactions, but over-hydrogenation into alkanes highly decreases olefin selectivity. Using phenylacetylene semi-hydrogenation as a model reaction, here we explore the optimization approaches toward better Pd catalysts for alkyne semi-hydrogenation through investigating support effect and metal-support interactions. The results show that the states of Pd with supports can be tuned by varying oxide reducibility, loading ratios, and post-treatments. In our system, 0.06 wt.% Pd on rutile-TiO2 nanorods shows the highest activity owing to the synergistic effects of single-atoms and clusters. Support reducibility can change the filling degrees of Pd 4d orbitals through varying interfacial bonding strengths, which further affect catalytic activity and selectivity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhengzhou University (Natural Science Edition) is the property of Journal of Zhengzhou University (Natural Science Edition) Editorial Office 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.)

Steady-state, differential reaction rates for CO oxidation, with stoichiometric O2:CO feeds, were measured in the presence and absence of H2O over Pt catalysts supported on thin films of CeFeOx, FeOx, CeOx, and LaFeO3 that had been deposited on γ-Al2O3 by Atomic Layer Deposition. Prior to rate measurements, each catalyst was oxidized and reduced five times at 1073 K. Only the oxidized Pt/CeFeOx/γ-Al2O3 catalyst exhibited significantly increased CO oxidation rates upon the introduction of H2O. A relatively small deuterium isotope effect was observed and suggests that O–H bond cleavage is not involved in the kinetically relevant step of this process. The nature of the catalyst support, the pretreatment of the catalyst, and the effects of Pt particle size are discussed in relation to the observed H2O promotion of CO oxidation. [ABSTRACT FROM AUTHOR]

Aqueous-phase reforming (APR) is an attractive process to produce bio-based hydrogen from waste biomass streams, during which the catalyst stability is often challenged due to the harsh reaction conditions. In this work, three Pt-based catalysts supported on C, AlO(OH), and ZrO2 were investigated for the APR of hydroxyacetone solution in a fixed bed reactor at 225 °C and 35 bar. Among them, the Pt/C catalyst showed the highest turnover frequency for H2 production (TOF of 8.9 molH2 molPt -1 min -1) and the longest catalyst stability. Over the AlO(OH) and ZrO2 supported Pt catalysts, the side reactions consuming H2, formation of coke, and Pt sintering result in a low H2 production and the fast catalyst deactivation. The proposed reaction pathways suggest that a promising APR catalyst should reform all oxygenates in the aqueous phase, minimize the hydrogenation of the oxygenates, maximize the WGS reaction, and inhibit the condensation and coking reactions for maximizing the hydrogen yield and a stable catalytic performance. [ABSTRACT FROM AUTHOR]

It is difficult for traditional anchoring structures to meet the tight construction period and high support effect requirements of deep foundation pit projects in soft soil areas, Therefore, a tensioning embedded composite drainage anchoring structure was proposed. By analyzing the anchoring mechanism of the new support structure, it can be concluded that the force acting on the anchor rod during the excavation process is divided into three stages: pre-tensioning stage, increasing end resistance stage and anchoring failure stage; a method for calculating the bearing capacity of new anchor rods was provided; the support effect and drainage characteristics of the new structure were simulated and analyzed by using finite element software. The results show that: the axial force distribution of the new anchor rod is different from that of the ordinary anchor rod, and there is a sharp increase in axial force at the pre-tensioned anchor head position; compared to ordinary anchor, the new anchoring structure has better support effect, which can reduce the maximum horizontal displacement of the slope by 37.2% and is more conducive to the stability of the foundation pit; the new anchoring support structure has good drainage effect and can quickly dissipate the pore water pressure near the free slope surface. [ABSTRACT FROM AUTHOR]

Herein, Ir/CeO2 catalysts were prepared using the deposition–precipitation method with NaOH or urea as the precipitating agent or using sol immobilization with tetrakis(hydroxymethyl)phosphonium chloride (THPC) as the protective and reducing agent. The effect of the preparation method on Ir catalyst activity was evaluated in the liquid-phase catalytic decomposition of hydrous hydrazine to hydrogen. Ir/CeO2 prepared using sol immobilization and DP NaOH showed the best activity (1740 h−1 and 1541 h−1, respectively) and yield of hydrogen (36.6 and 38.9%). Additionally, the effect of the support was considered, using TiO2 and NiO in addition to CeO2. For this purpose, the sol immobilization of preformed nanoparticles technique was considered because it allows the same morphology of the immobilized particles to be maintained, regardless of the support. Ir deposited on NiO resulted in the most selective catalyst with a H2 yield of 83.9%, showing good stability during recycling tests. The catalysts were characterized using different techniques: X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with an X-ray detector (EDX) and inductively coupled plasma–mass spectroscopy (ICP-MS). [ABSTRACT FROM AUTHOR]

Support effect is an important issue in heterogeneous catalysis, while the explicit role of a catalytic support is often unclear for catalytic reactions. A systematic density functional theory computational study is reported in this paper to elucidate the effect of a model boron nitride (BN) support on the first N-H bond activation step of NH3 on Run (n = 1, 2, 3) metal clusters. Geometry optimizations and energy calculations were carried out using density functional theory (DFT) calculation for intermediates and transition states from the starting materials undergoing the N-H activation process. The primary findings are summarized as follows. The involvement of the model BN support does not significantly alter the equilibrium structure of intermediates and transition states in the most favorable pathway (MFP). Moreover, the involvement of BN support decreases the free energy of activation, ΔG≠, thus improving the reaction rate constant. This improvement is more obvious at high temperatures like 673 K than low temperatures like 298 K. The BN support effect leading to the ΔG≠ decrease is most significant for the single Ru atom case among all three cases studied. Finally, the involvement of the model BN may change the spin transition behavior of the reaction system during the N-H bond activation process. All these findings provide a deeper insight into the support effect on the N-H bond activation of NH3 for the supported Ru catalyst in particular and for supported transition metal catalysts in general. [ABSTRACT FROM AUTHOR]

Catalyst support morphology strongly influences its surface and structural properties, therefore, may have a significant impact on their reactivity in heterogeneous catalysis. Herein, the Pd/In 2 O 3 /CeO 2 -x (loaded with 1 wt% Pd and In 2 O 3) catalysts with different morphologies of rods(r), cubes(c) and irregularity(w) shapes were prepared by hydrothermal method and impregnation method. At temperature of 275–425 °C, as-prepared catalysts were evaluated for hydrogen production from methanol steam reforming (MSR). The activity data showed the outstanding performance of the rod-shaped Pd/In 2 O 3 /CeO 2 catalysts, exhibiting the complete conversion of methanol and particularly low CO (1.3%) at 375 °C. The structural properties and physicochemical of Pd/In 2 O 3 /CeO 2 -x with different morphologies were characterized by means of X-ray diffraction (XRD), high resolution transmission microscopy (HR-TEM), CO pulse chemisorption, X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption of methanol (CH 3 OH-TPD). Activity data and catalyst characterization results correlated, and indicated that the excellent reactivity for the rod-shaped Pd/In 2 O 3 /CeO 2 catalysts in MSR is ascribed to the large particle size of palladium nanoparticles and the abundant oxygen vacancies induced by the strong interaction between Pd, In and Ce. HR-TEM results revealed that rod-like CeO 2 mainly expose (110) crystalline surface with high mobility of surface oxygen and possess the most abundant surface oxygen vacancies with the low formation energy, facilitating the formation of active species of Pd0 on catalyst surface, and promoting the activation and adsorption of methanol and water molecules. Furthermore, the rod-shaped Pd/In 2 O 3 /CeO 2 catalysts showed excellent reactivity and stability in MSR for 30 h, demonstrating its potential of being used as catalysts in methanol steam reforming in PEMFC systems. Table of Contents. [Display omitted] • The morphology of CeO 2 greatly influence the catalytic performance over Pd/In 2 O 3 catalysts. • Nanorod-like Pd/In 2 O 3 /CeO 2 -r catalysts with mainly exposed (110) crystal facet exhibit high MSR activity. • The large size of palladium nanoparticles facilitates H 2 dissociation and methanol activation. • The synergistic effect between Pd/In 2 O 3 and of CeO 2 dominate the MSR catalytic performance. • The number of oxygen vacancies are vital for superior performance of Pd/In 2 O 3 /CeO 2 -r catalysts. [ABSTRACT FROM AUTHOR]

The precast lining segments, pea-gravel backfilling and grouting are adopted in the double-shield TBM（tunnel boring machine） construction, which makes the segments, backfill layer and surrounding rock form an integral supporting structure. The property and compactness of pea-gravel backfill grouting is an important index affecting the working performance of TBM tunnel. On the basis of a diversion tunnel constructed by the double shield TBM, the performance of pea-gravel backfill grouting in different parts was studied through laboratory tests. The effects of the performance and compactness of backfilled pea-gravel on the support effect were analyzed by means of numerical simulation. The results show that there are great differences in the elastic modulus and uniaxial compressive strength of pea gravel due to the uneven density of grouting. When there is no void between the lining and the pea-gravel, the different parameters of the pea-gravel have little effect on the stress distribution of segments, but the stress in various parts of the lining varies. The stress state of the hollow part of the lining and pea-gravel is different from that with no void. There is a relatively obvious stress condition in the hollow part of the segment, and the stress value exceeds the design value of concrete tensile strength. In tunnel construction, we should pay attention to whether the lining is closely combined with the pea-gravel and strengthen the quality supervision of pea-gravel backfilling and grouting. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Ligand‐protected gold (Aun) clusters sometimes need the removal of organic ligands to expose more active sites and reduce steric hindrance in catalytic reactions, and large amount of organic and inorganic materials usually need to be employed as supports to anchor Aun clusters through different interaction mechanisms. Whereas, less comprehensive summaries have been provided about the crucial contribution of various supports to the catalytic performance of the supported Aun clusters. Herein, this review firstly summarizes synthesis methods (e.g., impregnation and encapsulation processes) for the supported Aun cluster catalysts, and then mainly points out specific contributions of support effect in a great diversity of catalytic reactions, as well as deep interaction mechanisms. Besides, opportunities and challenging issues will be stated towards supported Aun clusters, in terms of improving catalytic performance and structural stability of Aun clusters in the demand of catalysis. [ABSTRACT FROM AUTHOR]

As the notch location of engineered components suffers from size effect, thereby making it difficult to accurately predict the fatigue life of engineered components. This study briefly analyses the limitations of the traditional relative stress gradient model for analyzing the fatigue life of notched members. Subsequently, a relative stress gradient model with variable support effects is proposed. The fatigue data of various notched specimens with different materials were employed to verify the performance of the proposed model for size effect. The results show that the proposed model has satisfactory predictive performance. Compared with the conventional relative stress gradient model and critical distance method, the proposed model exhibited superior predictive capabilities.

We investigate the chemical and structural dynamics at the interface of In2O3/m-ZrO2and their consequences on the CO2hydrogenation reaction (CO2HR) under reaction conditions. While acting to enrich CO2, monoclinic zirconia (m-ZrO2) was also found to serve as a chemical and structural modifier of In2O3that directly governs the outcome of the CO2HR. These modifying effects include the following: (1) Under reaction conditions (above 623 K), partially reduced In2O3, i.e., InOx(0 < x < 1.5), was found to migrate in and out of the subsurface of m-ZrO2in a semireversible manner, where m-ZrO2accommodates and stabilizes InOxby serving as a reservoir. The decreased concentration of surface InOxunder elevated temperatures coincides with significantly decreased selectivity toward methanol and a sharp increase of the reverse water-gas shift reaction. The reconstruction-induced variation of InOxconcentration appears to be one of the most important factors contributing to the altered catalytic performance of CO2HR at different reaction conditions. (2) The strong interactions and reactions between m-ZrO2and In2O3result in the activation of a pool of In-O bonds at the In2O3/m-ZrO2interface to form oxygen vacancies. On the other hand, the high dispersity of In2O3nanostructures onto m-ZrO2prevents their over-reduction under catalytically relevant conditions (up to 673 K), when bare In2O3is unavoidably reduced into the metallic phase (In0). The relationship between the extent of reduction of In2O3and catalytic performance (CO2conversion, CH3OH selectivity, or yield of CH3OH) suggests the presence of an optimum coverage of surface InOxand oxygen vacancies under reaction conditions. The conventional model that links catalytic performance solely to the coverage of oxygen vacancies appears invalid in the present case. In situ analysis also allows the observation of surface reaction intermediates and their interconversions, including the reduction of CO3∗ into formate, a precursor for the formation of methanol and CO. The combinative ex situ and in situ study sheds light on the reaction mechanism of the CO2HR on In2O3/m-ZrO2-based catalysts. Our findings on the large-scale surface reconstructions, support effect, and the reaction mechanism of In2O3/m-ZrO2for CO2HR may apply to other related metal oxide catalyzed CO2reduction reactions.

5-6 nm hydrophilic NixCo(1-x) NPs was synthesized by a cost-effective and scalable method and was coated onto conductive substrates without any binders or additives thanks to its small particle effect and possiblely magnetic effects. Then, the NixCo(1-x) NPs can be transformed into NixCo(1-x)(OH)2 by an OER-activating strategy. Optimized by the composition effect, the Ni0.8Co0.2/CF exhibits best activity for supercapacitors (2124F/g). Underling mechanism of the OER evolution process well studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectrometry, X-ray absorption near-edge spectra (XANES). Density functional theory (DFT) calculations was performed and verify the synergistic effect of nickel and cobalt and the support effect.

Catalytic conversion of biomass-derived ethanol into n-butanol through Guerbet coupling reaction has become one of the key reactions in biomass valorization, thus attracting significant attention recently. Herein, a series of supported Cu catalysts derived from Ni-based hydrotalcite (HT) were prepared and performed in the continuous catalytic conversion of ethanol into butanol. Among the prepared catalysts, Cu/NiAlOx shows the best performance in terms of butanol selectivity and catalyst stability, with a sustained ethanol conversion of ~35% and butanol selectivity of 25% in a time-on-stream (TOS) of 110 h at 280 °C. While for the Cu/NiFeOx and Cu/NiCoOx, obvious catalyst deactivation and/or low butanol selectivity were obtained. Extensive characterization studies of the fresh and spent catalysts, i.e., X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Hydrogen temperature-programmed reduction (H2-TPR), reveal that the catalysts' deactivation is mainly caused by the support deconstruction during catalysis, which is highly dependent on the reducibility. Additionally, an appropriate acid–base property is pivotal for enhancing the product selectivity, which is beneficial for the key process of aldol-condensation to produce butanol. [ABSTRACT FROM AUTHOR]

The proton exchange membrane water electrolyzer (PEM-WE) is a well-known green technology for hydrogen production. The main obstacle to its development, on a large scale, is the sluggish kinetics of the oxygen evolution reaction (OER). At present, the design of acid-stable electrocatalysts with low overpotential and excellent stability for the OER constitutes an important activity in electrocatalysis. This review presents an analysis of the fundamentals and strategies for the design of advanced electrocatalysts for oxygen evolution, reaction mechanisms, and OER descriptors. The scrutiny of OER electrocatalysts, with elemental composition from single- to multielemental, are presented. In addition, the purpose of high-entropy alloys (HEAs), a recent research strategy, for the design of advanced materials is summarized. Briefly, the effect of support materials, which are beneficial for modulating the electronic properties of catalysts, is presented. Finally, the prospects for the development of acidic OER electrocatalysts are given. [ABSTRACT FROM AUTHOR]

The hydrogenation of biomass-based furan compounds is an important step for the catalytic valorization of biobased chemicals. In this work, Ru-based catalysts supported on different supports, such as HY, MgO and Amberlyst-15, were prepared and estimated for the hydrogenation of dimethyl 2,5-furandicarboxylate (FDMC). Among them, Ru/HY provided a desirable yield of 99.4% for tetrahydrofuran-2,5-dicarboxylic acid dimethyl ester (THFDMC) under 90 °C and 3 MPa H2. Based on catalyst characterization, Ru/HY could offer more surface Ru0 species and carbon radical intermediates than other catalysts, which could largely favor the activation of hydrogen and then promote the hydrogenation of FDMC over Ru/HY. [ABSTRACT FROM AUTHOR]

The spatial effect at the end of the foundation pit partition wall is significant, and the displacement of the retaining wall and soil caused by its demolition leads to an additional displacement and bending moment of the adjacent pile foundations, which in turn deteriorates the work behavior of the pile foundation. Taking the project of an open tunnel under a viaduct located in Hangzhou as an example, site monitoring was performed to determine the effect of the demolition of the partition wall on the displacement of the surrounding retaining wall and the soil in the adjacent area and the monitoring data were compared to the finite element analysis results to check the rationality of the finite element model. This model was used to study the influence of the distance from the pile foundation to the partition wall as well as the stiffness of the retaining wall on the displacement and bending moment of the pile foundation during excavation. These results indicate that because of the support effect of the foundation pit partition wall on the retaining wall, the spatial effect at the end of the partition wall is large, and the displacement and bending moments of the pile foundation in the vicinity of the partition wall are lower than those in the far distance. Demolition of the partition wall will increase the displacement and bending moment of adjacent pile foundations, and this effect decreases with increasing distance. The range of influence of the spatial effect at the end of the partition wall is approximately 1.1 times the depth of the foundation pit. When the pile foundation is in the immediate vicinity of the partition wall, the response of the front-row and rear-row piles to the demolition of the partition wall is significantly different. The front row piles are more affected, while the rear row piles are less affected. As the distance increases, the difference in response gradually decreases and tends to be consistent. As the stiffness of the retaining wall increases, the effect of the demolition of the partition wall on the pile foundation decreases. It is recommended that the stiffness of the supporting system near the partition wall be reduced appropriately, and the partition wall should be set at the foundation pit section near the pile foundation, but the response of the foundation pit and the adjacent pile foundation should be paid close attention to when the partition wall is demolished. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) assisted oxidative dehydrogenation of propane over Ga-modified catalysts is highly sensitive to the identity of support, but the underlying cause of support effects has not been well established. In this article, SSZ-13, SSZ-39, ZSM-5, silica and γ-Al2O3 were used to load Ga species by incipient wet impregnation. The structure, textural properties, acidity of the Ga-based catalysts and the process of CO2-assisted oxidative dehydrogenation of propane were examined by X-ray diffraction (XRD), nitrogen physisorption (N2 physisorption), ammonia temperature-programmed desorption (NH3-TPD), pyridine chemisorbed Fourier transform infrared spectra (Py-FTIR), OH-FTIR and in situ FTIR. Evaluation of the catalytic performance combined with detailed catalyst characterization suggests that their dehydrogenation activity is positively associated with the number of acid sites in middle strength, confirming that the Lewis acid sites generated by Ga cations are the active species in the reaction. Ga/Na-SSZ-39(9) also has feasible acidic strength and a unique channel structure, which is conducive to the dissociative adsorption of propane and desorption of olefins. The Ga/Na-SSZ-39(9) catalysts showed superior olefins selectivity and catalytic stability at 600 ℃ compared to any other catalysts. This approach to quantifying support acid strength, and channel structure and applying it as a key catalytic descriptor of support effects is a useful tool to enable the rational design of next-generation CO2-assisted oxidative dehydrogenation catalysts. [ABSTRACT FROM AUTHOR]

Catalytic oxidation of CH4 over nonprecious Ni/CeO2 catalysts has attracted wide attention. Controlling the morphology of a CeO2 support can enhance the CH4 oxidation activity without changing the catalyst composition. Herein, a series of 2 wt % Ni/CeO2 nanocatalysts with different CeO2 support morphologies (nanoparticles (P), rods (R), cubes (C)) and synthetic procedures (precipitation, sol-gel (SG)) were evaluated for their CH4 oxidation performance. The redox properties of CeO2 supports and corresponding Ni loaded catalysts were characterized by H2-temperature-programmed reduction and oxygen storage capacity (OSC) measurements. The relationship among the CeO2 morphologies, surface areas, redox properties, and CH4 oxidation activity for both CeO2 supports and Ni/CeO2 catalysts was established. The findings suggest that CeO2-R has a greater amount of surface oxygen vacancies as well as an improved OSC and CH4 oxidation activity compared to CeO2-P and CeO2-C supports. The same CH4 oxidation activity pattern was observed for the Ni containing catalysts (Ni/CeO2-R > Ni/CeO2-P > Ni/CeO2-C). Increasing the CeO2 surface area by using a sol-gel synthesis method (CeO2-SG) improved the amount of surface oxygen vacancies and CH4 oxidation performance of CeO2-SG and Ni/CeO2-SG compared to CeO2-R and Ni/CeO2-R, respectively. Finally, all studied Ni/CeO2 nanocatalysts showed improved hydrothermal stability compared to conventional Pd/Al2O3. [ABSTRACT FROM AUTHOR]

We present a detailed mechanistic study of HER at the sulfur vacancy V S of 2H–MoS 2. We evaluate the Volmer, Tafel, and Heyrovsky transition states for the different possible reaction steps, determining the activation energy as a function of the electrochemical potential via grand-canonical density functional theory. The results show that the Volmer and Heyrovsky steps depend on the electrochemical potential and the activation energies decrease for more negative potentials, while this is not the case for the Tafel step, for which the activation energy is constant. From the activation energies at −0.2 V vs SHE, it can be concluded that during HER on V S a first hydrogen atom is adsorbed as a spectator via a Volmer step. Then, the catalytic cycle consists of a Volmer and a Heyrovsky step, with the latter being rate determining. In addition, we investigate for the first time the effect of a conductive support on the HER activity of these sulfur vacancies. Our results show that copper, gold and graphite supports have little effects on the activation energies of all steps. Hence, we conclude that cheap, acid-stable, high-surface area carbon supports are well suited for MoS 2 -based HER catalysts. [Display omitted] • Potential-dependent activation energies reveal the HER mechanism on S-defects of MoS2 as Volmer- Heyrovsky with a spectator H∗. • The defect density has little influence on the S-vacancy based HER kinetics. • Support and nanosheet size effects are found to be small, hence large specific surface area carbon supports are adequate. [ABSTRACT FROM AUTHOR]

The hydrodeoxygenation (HDO) of m‐cresol was investigated at 340 °C under 30 bar as total pressure over molybdenum oxide‐based catalysts. 10 wt.% Mo were first deposited on various supports (ZrO2, TiO2, Al2O3 and COK12). The use of oxophilic ZrO2 and TiO2 supports allowed to obtain the highest HDO catalytic performances. This result could be in link with the reducibility of Mo, which was found to be dependent on the support nature. Several catalysts containing both W and Mo in oxide phase supported on ZrO2 were then prepared using various heteropolyacids as precursors (H4SiMoxW12‐xO40 with x=0, 3, 6, 9 and 12). A synergy was observed between Mo and W and the best catalytic performance was obtained for SiMo9W3/ZrO2. More importantly, the presence of W improved the reducibility of Mo6+ to Mo5+ species, which quantity was correlated to catalytic activity suggesting that Mo5+ could be the active phase in HDO. [ABSTRACT FROM AUTHOR]

There has been a global effort in the past decade, especially in major coal-producing countries, toward understanding the mechanics involved in the stability of coal mine ribs. Buckling and spalling of mine ribs are known to have an impact on their stability and degradation. The generation, propagation, and coalescence of cracks in mine pillar ribs are significantly affected by the overburden depths. In addition, the in situ stress magnitudes tend to affect the rib damage process. High horizontal stresses and increased depths can lead to unfavorable stress conditions, inducing coal mass damage and strength loss. Understanding the dynamics involved in rib behavior will inform better rib control practices. This study intended to assess the effect of mining depth, mining height, and supports on coal mine rib stability. In this research, the response of the coal mass was studied using distinct element modeling to better understand the failure process of coal mine ribs. The study confirmed mining depth as a significant factor controlling the rib loading and failure mechanism. In addition, increased mining heights increased the rib deformation and failure process. The evaluated support effect revealed that at shallower depths, shorter bolt lengths are sufficient to control rib stability. Increasing the bolt length for depths greater than 250 m is in order, but higher depths do not correlate with longer supports. The approach used in this study demonstrated its capacity to be used in designing rib support requirements and understanding coal mass and support mechanisms. [ABSTRACT FROM AUTHOR]

Herein, Ir/CeO2 catalysts were prepared using the deposition–precipitation method with NaOH or urea as the precipitating agent or using sol immobilization with tetrakis(hydroxymethyl)phosphonium chloride (THPC) as the protective and reducing agent. The effect of the preparation method on Ir catalyst activity was evaluated in the liquid-phase catalytic decomposition of hydrous hydrazine to hydrogen. Ir/CeO2 prepared using sol immobilization and DP NaOH showed the best activity (1740 h−1 and 1541 h−1, respectively) and yield of hydrogen (36.6 and 38.9%). Additionally, the effect of the support was considered, using TiO2 and NiO in addition to CeO2. For this purpose, the sol immobilization of preformed nanoparticles technique was considered because it allows the same morphology of the immobilized particles to be maintained, regardless of the support. Ir deposited on NiO resulted in the most selective catalyst with a H2 yield of 83.9%, showing good stability during recycling tests. The catalysts were characterized using different techniques: X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with an X-ray detector (EDX) and inductively coupled plasma–mass spectroscopy (ICP-MS).

Support effect is an important issue in heterogeneous catalysis, while the explicit role of a catalytic support is often unclear for catalytic reactions. A systematic density functional theory computational study is reported in this paper to elucidate the effect of a model boron nitride (BN) support on the first N-H bond activation step of NH3 on Run (n = 1, 2, 3) metal clusters. Geometry optimizations and energy calculations were carried out using density functional theory (DFT) calculation for intermediates and transition states from the starting materials undergoing the N-H activation process. The primary findings are summarized as follows. The involvement of the model BN support does not significantly alter the equilibrium structure of intermediates and transition states in the most favorable pathway (MFP). Moreover, the involvement of BN support decreases the free energy of activation, ΔG≠, thus improving the reaction rate constant. This improvement is more obvious at high temperatures like 673 K than low temperatures like 298 K. The BN support effect leading to the ΔG≠ decrease is most significant for the single Ru atom case among all three cases studied. Finally, the involvement of the model BN may change the spin transition behavior of the reaction system during the N-H bond activation process. All these findings provide a deeper insight into the support effect on the N-H bond activation of NH3 for the supported Ru catalyst in particular and for supported transition metal catalysts in general.

Religion can influence the realization of happiness in older adults. However, the relationship between religious belief and happiness of older adults and its mechanisms are not very clear. Using 5177 individuals aged ≥ 60 years in China for empirical analysis, the results show that there is a significant positive relationship between religious belief and older adults' happiness. The frequency of religious participation has a significantly moderating effect on the relationship between institutional religious affiliation and happiness; participation has an effect on happiness for those involved in institutional religion, but not an affect for those with diffused beliefs, which reflects the participation effect. Social support plays a mediating role between religious belief and older adults' happiness. People with religious beliefs are more likely to form social relationships and gain social support from religious members and groups to improve their happiness, which reflects the support effect. In addition, the influence of religious belief on happiness with low socioeconomic status is more significant, and the influence in rural areas is also more significant, showing the heterogeneity of individual socioeconomic status and registered residence. The freedom of older adult-religious believers to participate in the legal activities of religious organizations should be fully guaranteed. The religious faith of older adults in the process of active aging should be given attention. [ABSTRACT FROM AUTHOR]

Musculoskeletal disorders constitute the leading work-related health issue. Mechanical loading of the lower back contributes as a major risk factor and is prevalent in many tasks performed in logistics. The study aimed to compare acute effects of exoskeletons with different functional mechanisms in a logistic task. Twelve young, healthy individuals participated in the study. Five exoskeletons with different functional mechanisms were tested in a logistic task, consisting of lifting, carrying, and lowering a 13 kg box. By using electromyography (EMG), mean muscle activities of four muscles in the trunk were analyzed. Additionally, kinematics by task completion time and range of motion (RoM) of the major joints and segments were investigated. A main effect was found for Musculus erector spinae, Musculus multifidus, and Musculus latissimus dorsi showing differences in muscle activity reductions between exoskeletons. Reduction in ES mean activity compared to baseline was primarily during lifting from ground level. The exoskeletons SoftExo Lift and Cray X also showed ES mean reduction during lowering the box. Prolonged task duration during the lifting phase was found for the exoskeletons BionicBack, SoftExo Lift, and Japet.W. Japet.W showed a trend in reducing hip RoM during that phase. SoftExo Lift caused a reduction in trunk flexion during the lifting phase. A stronger trunk inclination was only found during lifting from the table for the SoftExo Lift and the Cray X. In conclusion, muscle activity reductions by exoskeleton use should not be assessed without taking their designed force paths into account to correctly interpret the effects for long-term injury prevention. [ABSTRACT FROM AUTHOR]

• Heterogeneous catalysis has emerged as a pivotal way for the plastic upcycling. • We summarized support effects on catalytic recycling of waste plastics. • We offered an outlook for the heterogeneous catalytic plastic recycling. Heterogeneous supported metal catalysts have played a pivotal role in modern industrial initiatives dedicated to the chemical upcycling of end-of-life plastics. Leveraging the multifaceted effects of supports to customize the structural features of catalysts constitutes a widely embraced and effective strategy for enhancing catalytic performance. Nonetheless, the nascent field of plastics chemical upcycling lags in progress, primarily attributed to the intricate and versatile nature of these support effects. In this review, we provide a comprehensive overview of the current state of research into diverse support effects employed in the context of plastic upcycling. We delve deeply into the structure-performance relationship, scrutinizing key aspects such as metal-support interactions (MSI), promoter effects, support-polymer interactions, and bifunctional catalysis. Finally, we offer a forward-looking discourse, presenting an outlook for the advancement of heterogeneous catalysts built upon the amalgamation of the identified support effects and exploring potential auxiliary functions of these support materials. This discussion serves to provide essential guidance for the design of multifunctional catalysts with a focus on enhancing the process of plastic upcycling. [ABSTRACT FROM AUTHOR]

[Display omitted] • MgAl 2 O 4 supported Ru catalysts are developed via ball milling and microwave heating. • 0.5Ru/MgAl 2 O 4 shows high catalytic activity for diphenyl ether hydrogenolysis. • 0.5Ru/MgAl 2 O 4 exhibits strong electron transfer from MgAl 2 O 4 to Ru. • Abundant electron-rich Ru0 species on MgAl 2 O 4 enhance the catalytic activity. The direct cleavage of C−O bonds in lignin and its derivatives via hydrogenolysis is an essential reaction process for lignin conversion. Herein, we design a MgAl 2 O 4 supported Ru catalyst using a facile and green method involving ball milling and microwave heating. The optimal catalyst, 0.5Ru/MgAl 2 O 4 , displayed enhanced catalytic performance for 4−O−5 linkage scission compared to 0.5Ru/Al 2 O 3 and 0.5Ru/MgO, achieving a tuenover frequency of 352.9 h−1 for diphenyl ether (DPE) conversion. 0.5Ru/MgAl 2 O 4 with low Ru loading achieved complete conversion of DPE, with 43.8% yield of cyclohexane (CHE) and 42.6% yield of cyclohexanol (CHL) after 2 h at 160 °C and 1.5 MPa H 2. The promising catalytic activity can be attributed to the abundant electron-rich Ru0 species with high dispersion formed on MgAl 2 O 4 , derived from the strong electron transfer from the support to Ru. The reaction mechanism for the direct cleavage of the 4−O−5 bond, followed by phenyl ring hydrogenation, was confirmed by rigorous experiments. This work provides an inspiring idea for developing efficient heterogeneous catalysts for the utilization of lignin resources via hydrogenolysis. [ABSTRACT FROM AUTHOR]

The proton exchange membrane water electrolyzer (PEM-WE) is a well-known green technology for hydrogen production. The main obstacle to its development, on a large scale, is the sluggish kinetics of the oxygen evolution reaction (OER). At present, the design of acid-stable electrocatalysts with low overpotential and excellent stability for the OER constitutes an important activity in electrocatalysis. This review presents an analysis of the fundamentals and strategies for the design of advanced electrocatalysts for oxygen evolution, reaction mechanisms, and OER descriptors. The scrutiny of OER electrocatalysts, with elemental composition from single- to multielemental, are presented. In addition, the purpose of high-entropy alloys (HEAs), a recent research strategy, for the design of advanced materials is summarized. Briefly, the effect of support materials, which are beneficial for modulating the electronic properties of catalysts, is presented. Finally, the prospects for the development of acidic OER electrocatalysts are given.

Catalytic conversion of biomass-derived ethanol into n-butanol through Guerbet coupling reaction has become one of the key reactions in biomass valorization, thus attracting significant attention recently. Herein, a series of supported Cu catalysts derived from Ni-based hydrotalcite (HT) were prepared and performed in the continuous catalytic conversion of ethanol into butanol. Among the prepared catalysts, Cu/NiAlOx shows the best performance in terms of butanol selectivity and catalyst stability, with a sustained ethanol conversion of ~35% and butanol selectivity of 25% in a time-on-stream (TOS) of 110 h at 280 °C. While for the Cu/NiFeOx and Cu/NiCoOx, obvious catalyst deactivation and/or low butanol selectivity were obtained. Extensive characterization studies of the fresh and spent catalysts, i.e., X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Hydrogen temperature-programmed reduction (H2-TPR), reveal that the catalysts’ deactivation is mainly caused by the support deconstruction during catalysis, which is highly dependent on the reducibility. Additionally, an appropriate acid–base property is pivotal for enhancing the product selectivity, which is beneficial for the key process of aldol-condensation to produce butanol.

The chemical looping process, where an oxygen carrier is reduced and oxidized in a cyclic manner, offers a promising option for hydrogen production through splitting water because of the much higher water splitting efficiency than solar electrocatalytic and photocatalytic process. A typical oxygen carrier has to comprise a significant amount of inert support, to maintain stability in multiple redox cycles, thereby resulting in a trade-off between the reaction reactivity and stability. Herein, we proposed the use of ion-conductive yttria-stabilized zirconia (YSZ) support Fe2O3 to prepare oxygen carriers materials. The obtained Fe2O3/YSZ composites showed high reactivity and stability. Particularly, Fe2O3/YSZ-20 (oxygen storage capacity, 24.13%) exhibited high hydrogen yield of ∼10.30 mmol g−1 and hydrogen production rate of ∼0.66 mmol g−1 min−1 which was twice as high as that of Fe2O3/Al2O3. Further, the transient pulse test indicated that active oxygen diffusion was the rate-limiting step during the redox process. The electrochemical impedance spectroscopy (EIS) measurement revealed that the YSZ support addition facilitated oxygen diffusion of materials, which contributed to the improved hydrogen production performance. The support effect obtained in this work provides a potentially efficient route for the modification of oxygen carrier materials.

Oxidative steam reforming of ethanol (OSRE) to produce hydrogen has been investigated over a series of supported PtRu catalysts, with different supports. Bimetallic PtRu-based catalysts were prepared by the impregnation method using H2PtCl6 and RuCl3 as precursors. Six supports (reducible oxides of ZrO2, CeO2, and Co3O4, and irreducible oxides of ZnO, Al2O3, and NiO) were chosen to fabricate bimetallic catalysts. The catalytic performance of the OSRE reaction in the series of PtRu-based samples was evaluated using a fixed-bed flow reactor under atmospheric pressure. In front reaction, the catalyst was pre-activated by reduction under 200°C for 3 h. The gas hourly space velocity was adjusted at 66,000 h−1, and the optimal molar ratios of the H2O/EtOH and O2/EtOH feeds were 4.9 and 0.44, respectively. The results indicated that the PtRu supported on the ZrO2 and CeO2 exhibited superior catalytic performance in the OSRE reaction under a low temperature (a TR of approximately 320°C) for producing the main products of H2 and CO2 with lower CO and CH4 by-products. Also, it was quite stable during a long time evaluation; the maximum YH2 maintained at 4.5–4.2, and the CO distribution approached 3.3–3.5 mol% around 84 h test at 340°C over the PtRu/ZrO2 catalyst.

[Display omitted] • The LDH with the modulated M2+/Al3+ ratio was fabricated by the aluminate intercalation. • Spinel-type MII-MIII complex oxides with high specific surface areas were obtained at 500 oC. • The Ni/MgAl 2 O 4 showed high selectivity and superior stability during the reaction process. • The catalyst also exhibited excellent resistance against carbonaceous compound deposition. Even though Ni catalysts have shown promising performance in the semi-hydrogenation of ethylene, the selectivity and stability remain to be improved so that they may be used to replace expensive noble metal catalysts. Herein, an aluminate-intercalated NiMgAl-layered double hydroxide (LDH) was prepared through a facile co-precipitation approach, and then a topotactic transformation strategy was employed to convert the tailored LDH precursor to the spinel catalyst. More than 99% of the Ni/MgAl 2 O 4 catalyst's conversion was achieved toward the semi-hydrogenation of acetylene at 140 °C, with a selectivity of more than 80%. Additionally, due to high specific surface area (309 m2/g) with tuned acidity, this catalyst showed outstanding resistance to the deposition of carbonaceous compounds and satisfactory long-term stability during a 28 hr test. It is hoped that this study will inspire the design of supported non-noble metal materials with high activity and efficiency towards organic or organo-thermal reactions, as well as provide a basic understanding of the role and impacts of intercalated aluminates in LDH. [ABSTRACT FROM AUTHOR]

In recent years, TBM has been widely applied in deep coal mining to lift the TBM tunneling efficiency and avoid accidents, and more flexible support schemes are expected and required. This research aims to evaluate the performance of the two different support schemes and to study the law of the support effect. A three-dimensional continuum model was established based on the available geological information, and the support effect at the three-dimensional level was studied by changing the support spacing and was assessed in term of the stress, displacement, failure zone, bolt force distributions, and axial deformation behavior of the tunnel. The results show that no matter what the geological condition was, the support of the non-radial support was a little lower than that of the radial support, and with a worse geological condition, the non-radial support had a better performance in the stabilizing tunnel. Additionally, the law of the support effect was found. The interlapping of the support influence domain was the essence of the increase in the support effect. Finally, according to the support law, the appropriate support spacing is found, which is smaller than 50% of the support influence domain length. [ABSTRACT FROM AUTHOR]

Co-existence of different surfaces in traditional polycrystalline heterogeneous catalysts imposes a challenge to induce different kinds of catalytic species and average reactivity. Supported metal/oxide model catalyst designed with equivalent well-defined surfaces and active species provides an opportunity to control the uniformity, maintain efficient activity, and understand catalytic mechanisms at the atomic and molecular levels. Herein, sub-20 nm perovskite-structure BaTiO 3 polyhedron nanocuboids and Zr-substituted rhombic dodecahedron nanocrystals were synthesized and employed as the oxide support for the subsequent uniform growth of 1–2 nm Pt nanoparticles. These Pt nanoparticles were well dispersed on the 12 equivalent (110) facets of BaTi 0.75 Zr 0.25 O 3 rhombic dodecahedra and on the 6 equivalent (100) facets of BaTiO 3 nanocuboids. The main active centers on the Pt/BaTi 0.75 Zr 0.25 O 3 catalysts in the oxidized surface layer of Pt (111) facets are Pt4+ versus Pt2+, which is in contrast to the oxidized surface layer of the Pt (100) facets on the Pt/BaTiO 3 cuboids where there are a greater number of Pt2+ species. Compared with Pt/BaTiO 3 nanocuboids, the Pt/BaTi 0.75 Zr 0.25 O 3 catalysts demonstrated higher CO catalytic oxidation activity with a lower apparent Arrhenius activation energy. This work advances our ability to synthesize metal/oxide model catalyst that offer equivalent facets and highly uniform active centers with reasonable surface area in order to gain insight in reaction mechanisms. [Display omitted] • Synthesis of sub-20 nm perovskite nanocubes and rhombic dodecahedra. • HRTEM/STEM image analysis for perovskite oxide and 1–2 nm Pt nanoparticles. • CO oxidation and DRIFTS characterization on two supported Pt catalysts. • XPS characterization for Pt4+ and Pt2+ active species dispersion analysis. [ABSTRACT FROM AUTHOR]

Methanation is capable of chemical storage of fluctuating renewable energy, which requires fundamental understanding of the dynamics of the kinetic processes taking place on the catalyst surface. In order to elucidate the impact of the catalyst support on the dynamics, Co‐based model catalysts were synthesized via double flame spray pyrolysis (DFSP) differing only in the support materials. In particular, Co nanoparticles of identical particle size distributions are supported on SiO2, TiO2 and SiO2‐TiO2 mixtures by independent formation of the support and the active metal by means of DFSP. The transient catalyst behavior was studied by step changes of the feed gas composition and the analysis of the reactor response with high temporal resolution, according to the periodic transient kinetics method. It was revealed that H2O adsorption strongly depends on the support with increasing sorption capacity from SiO2, via SiO2‐TiO2 to TiO2. The storage of H2O on the support induces a sorption‐enhancement effect and thereby promotes the transient CH4 formation rate for Co/TiO2 catalysts. Transient experiments before and after a steady‐state operation period under CO2 methanation reveal an unchanging reaction mechanism, while changes in selectivity towards CH4 and CO are observed together with a certain degree of deactivation. Hence, the support material was identified to play a major role in activity, selectivity and deactivation behavior for supported Co catalysts in CO2 methanation. [ABSTRACT FROM AUTHOR]

Metal-support interaction and catalyst pretreatment are important for industrial catalysis. This work investigated the effect of supports (SiO 2 , CeO 2 , TiO 2 and ZrO 2) for Cu–Pd catalyst with high Cu/Pd ratio (Cu/Pd = 33.5) regarding catalyst cost, and the reduction temperatures of 350 °C and 550 °C were compared. The activity based on catalyst weight follows the order of Si > Ce > Zr > Ti when reduced at 350 °C. The reduction temperature leads to the surface reconstruction over the SiO 2 , CeO 2 and TiO 2 catalysts, while results in phase transition over Cu–Pd/ZrO 2. The effect of reduction temperature on catalytic performance is prominent for the SiO 2 and ZrO 2 supported catalysts but not for the CeO 2 and TiO 2 ones. Among the investigated catalysts, Zr-350 exhibits the highest methanol yield. This work reveals the importance of the supports and pretreatment conditions on the physical-chemical properties and the catalytic performance of the Cu–Pd bimetallic catalysts. • Phase separation exists over Si-350, Si-550, Ti-350, Zr-350 and Zr-550. • The TOF over Si-350 is higher than the other three catalysts (280 °C). • Reduction temperature leads to the phase transition over ZrO 2 catalysts. • Surface structure reconstruction caused by reduction temperature exist over SiO 2 , CeO 2 and TiO 2 catalysts. • Effect of reduction temperature is prominent over the SiO 2 , CeO 2 and ZrO 2 supported catalysts. [ABSTRACT FROM AUTHOR]

Support materials are indispensable to promote the durability of iron oxides for chemical looping applications. However, the dilution effect of supports on the active phase would lead to decreased bulk oxygen conduction, thus leading to compromised activity. Here, we propose several Gd3+, La3+ and Nd3+ doped CeO 2 as active supports for iron oxides and investigate the support effect to improve hydrogen generation via chemical looping water gas shift. The characterizations show that the dopants improve the oxygen vacancy concentration in the CeO 2 lattice and Fe 2 O 3 /Ce 0.8 Gd 0.1 La 0.1 O 2-δ exhibits the most oxygen vacancy concentration among all the oxygen carriers. Pulse reactions of oxygen carriers show that an abundance of oxygen vacancy concentration can promote the lattice oxygen transfer in bulk, thus contributing to improved redox reactions. The high oxygen conductivity mitigates the dilution effect on the active phase. Therefore, Fe 2 O 3 /Ce 0.8 Gd 0.1 La 0.1 O 2-δ shows the highest hydrogen yield (∼9.49 mmol−1.g−1) and hydrogen generation rate (∼0.632 mmol.g−1.min−1) with only a slight decrease at 650 °C over 100 cycles. Overall, this work highlights the influence of support properties on the redox reactivity of iron oxides for chemical looping applications. [Display omitted] • Fe/Ce 0.8 Gd 0.1 La 0.1 O 2-δ shows record hydrogen generation performance at 650 °C. • Gd, La co-doped CeO 2 displays high oxygen vacancy concentration. • High oxygen vacancy concentration improves bulk oxygen conduction. • The performance remains stable at 650 °C for 100 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • MCM-41 (2D), SBA-15 (2D) and KIT-6 (3D) were used as supports for Cu-Mg species. • CuMg/SBA-15 exhibited 50.0% 1,2-PeD yield, surpassing reported Cu-based catalysts. • Larger 2D mesoporous structure endows suitable M−S interaction and Cu dispersion. • C FFA and S 1,2-PeD are related to Cu dispersion and Cu0/Cu+ ratio, respectively. • Dual adsorption sites of both MgO and Cu species promote the FFA ring-opening. Utilizing urea homogeneous precipitation method, Cu and Mg species were successfully supported on SBA-15, KIT-6, and MCM-41 respectively for furfuryl alcohol (FFA) hydrogenolysis to 1,2-pentanediol (1,2-PeD). The catalytic results showed that the yield of 1,2-PeD followed the order of CuMg/SBA-15 > CuMg/KIT-6 > CuMg/MCM-41, especially the maximum of 50.0 % over CuMg/SBA-15 surpassing that of most copper-based catalysts reported. It is found that FFA conversion dramatically increases with the raising of Cu dispersion, attributing to the high exposure of active sites. Meanwhile, the selectivity of 1,2-PeD is strongly depended on the Cu0/Cu+ ratio of catalyst and CuMg/SBA-15 with the highest value of 57.6 % is derived from the largest Cu0/Cu+ ratio. In a word, CuMg/SBA-15 shows the excellent activity along with stability owing to the synergy between large Cu0/Cu+ ratio and good Cu dispersion, providing by two-dimensional hexagonal straight channel arrangement with generous pore diameter. Innovatively, it is put forward that dual adsorption sites of both MgO and Cu species in the CuMg/SBA-15 catalyst promote the FFA ring-opening to yield 1,2-PeD based on the comparison of Cu dispersion, metal-support (M−S) interaction and the adsorption capacity for furan rings with Cu/SBA-15. This study provides a novel approach for catalyst design for this reaction, focusing on optimizing the catalytic performance by fine-tuning structure of the support. [ABSTRACT FROM AUTHOR]