Search

Co3O4 catalyst was prepared by means of precipitation method and its precursor was treated with formic acid to prepare H-Co3O4 catalyst. Their catalytic activities for N2O catalytic decomposition were studied. The results show that H-Co3O4 catalyst exhibits much higher catalytic activity than Co3O4, which may result from the larger BET surface area, especially the more amount of surface Co3+, enhanced reducibility and promoted desorption ability of oxygen species.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Controllable synthesis of well‐defined supported intermetallic catalysts is desirable because of their unique properties in physical chemistry. To accurately pinpoint the evolution of such materials at an atomic‐scale, especially clarification of the initial state under a particular chemical environment, will facilitate rational design and optimal synthesis of such catalysts. The dynamic formation of a ZnO‐supported PdZn catalyst is presented, whereby detailed analyses of in situ transmission electron microscopy, electron energy‐loss spectroscopy, and in situ X‐ray diffraction are combined to form a nanoscale understanding of PdZn phase transitions under realistic catalytic conditions. Remarkably, introduction of atoms (H and Zn in sequence) into the Pd matrix was initially observed. The resultant PdHx is an intermediate phase in the intermetallic formation process. The evolution of PdHx in the PdZn catalyst initializes at the PdHx/ZnO interfaces, and proceeds along the PdHx ⟨111⟩ direction. A palladium catalyst supported on ZnO is monitored in situ and in chemical environments relevant to catalysis. Structural evolution of PdZn intermetallic metal nanoparticles (NPs), visualized at an atomic scale, reveals the evolution of a PdHx intermediary species at the interface between PdHx and the ZnO support. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell 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.)

Co-Ce composite oxide catalysts have been prepared by the co-precipitation method using K2CO3 (Co-Ce-A), KOH (Co-Ce-B) and NH3·H2O (Co-Ce-C) as precipitants. The effect of different precipitants on the catalytic activity for N2O catalytic decomposition was investigated in a fixed-bed continuous flow reactor. The structure and properties of the catalysts were characterized by XRD, TEM, FT-IR, Raman, XRF, BET, EC, H2-TPR and O2-TPD. The results show that under the reaction conditions of N2O 0.1% and GHSV 10,000 h−1, the catalyst prepared by using K2CO3 as precipitant exhibits better N2O catalytic decomposition activity than that prepared by using KOH or NH3·H2O as precipitant. The XRD, TEM and BET results reveal that all the samples exist as a Co3O4 phase with the spinel structure though the precipitated precursors are different, while Co-Ce-A shows higher specific surface area and smaller crystalline size. Further characterizations results suggest that compared with Co-Ce-B and Co-Ce-C, Co-Ce-A possesses not only stronger interaction between Co and Ce species, but also higher electrical conductivity resulting from the more amount of residual K, which improves the reduction of Co3+-Co2+ and facilitates the desorption of surface oxygen species. Therefore, Co-Ce-A exhibits enhanced N2O catalytic decomposition activity. [ABSTRACT FROM AUTHOR]

Pd-Cu/palygorskite catalysts were prepared by a wet impregnation method using palygorskite (PC/N-Pal) and ultrasonic-treated palygorskite (PC/U-Pal) as the support. Their catalytic activities toward CO oxidation at room temperature and in humid circumstances were investigated. PC/U-Pal exhibits much higher catalytic activity and stability than PC/N-Pal under the conditions of 1.0 vol.% CO and 3.3 vol.% H2O in the feed gas. The X-ray diffraction results indicate that quartz impurities were eliminated from the Pal after the ultrasonic treatment, and more copper species exist in the form of Cu2Cl(OH)3 in PC/U-Pal. The temperature-programmed reduction results suggest that there is an enhanced reducibility of PC/U-Pal after ultrasonic treatment. Furthermore, the ultrasonic treatment can properly decrease the hydrophilicity of the support and catalyst, which may also contribute to the excellent catalytic performance. [ABSTRACT FROM AUTHOR]

ABSTRACT Polar polystyrene-isoprene-styrene (SIS) copolymers having epoxide groups and long polybutadiene (PB) branches were synthesized via the combination of in situ epoxidation, anionic polymerization and graft-onto reaction. They were characterized with 1H NMR, GPC, FT-IR, DSC, and contact angle test. Their polarity was determined by the epoxidation degree and graft efficiency. The epoxidation degree linearly increased with the epoxidation time. The graft efficiency decreased with the branch length, but increased with the epoxidation degrees. Although their glass transition temperature ( Tg) of diene blocks and flexibility properties had been negatively affected by in situ epoxidation, they could be modulated by the epoxidation degree, branch length, and branch density. Their Tg could be tailored by the branch length and branch density since they fitted the Fox equation very well, especially as the longer branches were grafted. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40303. [ABSTRACT FROM AUTHOR]

Abstract: Ni-based catalysts supported on SiO2 aerogel that is unpromoted (Ni/SiO2) or promoted (Ni/ZrO2–SiO2) with ZrO2 are prepared by the incipient-wetness impregnation method. Their catalytic activities for CO methanation in hydrogen-rich gases with 1vol.% CO are studied with a continuous flowing microreactor. It is found that the Ni/ZrO2–SiO2 catalyst shows higher catalytic activity, over which CO can be completely converted into CH4 at 240°C. However, CO cannot be completely converted until the temperature was raised to 320°C over the Ni/SiO2 catalyst under the same reaction conditions. Characterizations using FT-IR, XRD, TEM, NH3-TPD, H2-TPR and H2-TPD suggest that the formation of Si–O–Zr bond results in stronger acid strength and larger amounts of acid of the ZrO2–SiO2 support. The changes of acidity lead to the increase of the interaction between NiO species and the ZrO2–SiO2 support and then enhance the dispersion degree and the reduction degree of NiO species. Thus, the Ni/ZrO2–SiO2 catalyst possesses smaller Ni crystallite size, higher Ni dispersion, more active Ni species and stronger adsorption ability for H2, which may contribute to its higher catalytic activity for CO methanation. [ABSTRACT FROM AUTHOR]

• Heterostructures of MoS 2 and CdS are synthesized by a facile method. • MoS 2 /CdS heterojunction effectively inhibits the recombination of photo-generated electrons and holes. • The H 2 production rate of 15 wt% MoS 2 /CdS is 30.7 times higher than pure CdS. • Partially crystallized MoS 2 with abundant exposed edges provides active sites for photocatalytic reactions. We report a facile route to obtain MoS 2 /CdS heterostructure and tested for hydrogen production activity under visible light irradiation. The MoS 2 /CdS heterostructure containing 15 wt% MoS 2 exhibits the highest H 2 production rate of 27.720 mmol g−1 h−1, which is 30.7 times higher than CdS alone. This promotion of photocatalytic activity can be assigned to the modification of MoS 2 on CdS surfaces by forming interfacial interactions, which effectively inhibits the recombination of photo-generated electrons and holes. Meanwhile, MoS 2 exhibits a partially crystallized status, providing abundant exposed edges with coordinatively unsaturated S and Mo atoms as the photocatalytic active sites, thus facilitating hydrogen production. [ABSTRACT FROM AUTHOR]

[Display omitted] • The catalysts with ultra-low Pd loading are acquired by co-impregnation method. • Pd-Cu-In 0.25 /Al 2 O 3 exhibits better CO-PROX performance than Pd-Cu/Al 2 O 3. • There is a strong interaction between In 2 O 3 species and Pd-Cu/Al 2 O 3. • The low electron cloud density of Cu+ makes it easier to be oxidized to Cu2+. • Indium species promotes the reoxidation of Pd0 and reduces the formation of PdH x. The impact of Indium (In) doping upon the catalytic performance of Pd-Cu/Al 2 O 3 for carbon monoxide preferential oxidation (CO-PROX) in hydrogen (H 2) rich atmosphere at low temperature has been studied. A series of catalysts with extremely low palladium (Pd) loading (0.06 wt%) are synthesized by the facile co-impregnation method. When the In/copper (Cu) atomic ratio equals 0.25, Pd-Cu-In 0.25 /Al 2 O 3 can keep 40% CO conversion and 100% carbon dioxide (CO 2) selectivity at least 120 min at 30 °C, which is significantly superior to the catalytic performance of Pd-Cu/Al 2 O 3. The elaborate characterization findings reveal that the added In species to Pd-Cu/Al 2 O 3 causes Indium oxide (In 2 O 3) to generate, which produces the interaction of In 2 O 3 with Pd-Cu/Al 2 O 3 , further promoting the dispersion of copper chloride hydroxide (Cu 2 Cl(OH) 3). Moreover, the modification of In facilitates the re-oxidation of Pd0 to Pd+ through reducing the formation of palladium hydride (PdH x) during the CO-PROX reaction. Meanwhile, the addition of In leads to the decrease of Cu+ electron cloud density, making it easier to be oxidized to Cu2+. Collectively, the easy re-oxidation of Pd0 and Cu+ is favorable to fulfill the Wacker cycle between Pd and Cu species, thus improving the catalytic performance for CO-PROX. [ABSTRACT FROM AUTHOR]

Leaping the dragon gate Nanoscale phase transitions occur for a ZnO‐supported PdZn intermetallic under realistic acetylene hydrogenation conditions. In their Communication on page 4232 ff., D. S. Su, W. Zhang, B. Zhang, et al. observe the evolution of a PdHx intermediary species at the interface between PdHx and a ZnO support using in situ X‐ray diffraction and transmission electron microscopy. According to Chinese legend, Yulong carp will transform into dragons if they climb a waterfall. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell 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.)

The present work is aimed to improve the performance of Ni-based catalysts for biogas dry reforming by adding a second non-noble metal (Fe, Co, Cu) into a previously studied mesoporous Ni- CaO-ZrO2 nanocomposite. Biogas was simulated with equivalent methane and carbon dioxide for the dry reforming reaction. X-ray diffraction ( XRD), X-ray photoelectron spectroscopy ( XPS), N2 adsorption, temperature-programmed reduction ( TPR), thermogravimetric analysis ( TGA), and transmission electron microscopy ( TEM) measurements were taken to characterize the structural and textual properties of the bimetallic catalysts as well as the accumulated carbon deposition. The addition of Fe leads to a less ordering growth of mesopores of Fe-Ni- CaO-ZrO2 sample, and the existence of Cu results in a relatively larger portion of free NiO in Cu-Ni- CaO-ZrO2. Compared with Fe and Cu, the presence of Co could efficiently form a beneficial dual metal effect and enhance the strong metal support interaction between Ni and CaO-ZrO2, thus enhancing the activity and stability of the catalyst in biogas dry reforming reaction. [ABSTRACT FROM AUTHOR]

Controllable synthesis of well‐defined supported intermetallic catalysts is desirable because of their unique properties in physical chemistry. To accurately pinpoint the evolution of such materials at an atomic‐scale, especially clarification of the initial state under a particular chemical environment, will facilitate rational design and optimal synthesis of such catalysts. The dynamic formation of a ZnO‐supported PdZn catalyst is presented, whereby detailed analyses of in situ transmission electron microscopy, electron energy‐loss spectroscopy, and in situ X‐ray diffraction are combined to form a nanoscale understanding of PdZn phase transitions under realistic catalytic conditions. Remarkably, introduction of atoms (H and Zn in sequence) into the Pd matrix was initially observed. The resultant PdHx is an intermediate phase in the intermetallic formation process. The evolution of PdHx in the PdZn catalyst initializes at the PdHx/ZnO interfaces, and proceeds along the PdHx ⟨111⟩ direction. [ABSTRACT FROM AUTHOR]

Controllable synthesis of well‐defined supported intermetallic catalysts is desirable because of their unique properties in physical chemistry. To accurately pinpoint the evolution of such materials at an atomic‐scale, especially clarification of the initial state under a particular chemical environment, will facilitate rational design and optimal synthesis of such catalysts. The dynamic formation of a ZnO‐supported PdZn catalyst is presented, whereby detailed analyses of in situ transmission electron microscopy, electron energy‐loss spectroscopy, and in situ X‐ray diffraction are combined to form a nanoscale understanding of PdZn phase transitions under realistic catalytic conditions. Remarkably, introduction of atoms (H and Zn in sequence) into the Pd matrix was initially observed. The resultant PdHx is an intermediate phase in the intermetallic formation process. The evolution of PdHx in the PdZn catalyst initializes at the PdHx/ZnO interfaces, and proceeds along the PdHx ⟨111⟩ direction. A palladium catalyst supported on ZnO is monitored in situ and in chemical environments relevant to catalysis. Structural evolution of PdZn intermetallic metal nanoparticles (NPs), visualized at an atomic scale, reveals the evolution of a PdHx intermediary species at the interface between PdHx and the ZnO support. [ABSTRACT FROM AUTHOR]

The effect of acid treatment on the catalytic performance of CuO/Cryptomelane (CuO/CR) for CO preferential oxidation (CO-PROX) in H 2 -rich streams has been investigated. The CR supports are synthesized via the sol-gel approach. The hydrochloric acid or water is used to treat the CR support, and the corresponding CuO/CR catalysts are prepared by an initial wet impregnation method. Compared with the pristine CuO/CR and water-treated CuO/CR W catalysts, the acid-treated CuO/CR H exhibits the best catalytic activity with almost 100% of CO conversion at 110 °C, which can be maintained at least 100 h. The characterization results show that acid treatment decreases the K+ content in the CuO/CR H catalyst, which is conducive to the formation of more oxygen vacancies, thereby promoting the reducibility of CuO/CR H. This is the main reason for the high catalytic activity of the acid-treated CuO/CR H catalyst. Moreover, the abundant Brönsted acid sites on CuO/CR H are favorable for the desorption of acidic product CO 2 , which also could result in the significant promotion of the catalytic activity for CO-PROX. This study sheds a light on the importance of acid treatment for cryptomelane and provides an efficient catalyst for hydrogen purification. [Display omitted] • CuO/CR H exhibits better catalytic performance than CuO/CR W and CuO/CR. • The acid treatment is helpful for the generation of oxygen vacancy over CuO/CR H. • More oxygen vacancies promoted the improvement of the reducibility of CuO/CR H. • The improved reducibility of the CuO/CR H enhanced the CO-PROX reaction. • The enhanced Brönsted acid property favours the desorption of acidic product CO 2. [ABSTRACT FROM AUTHOR]

NiLa intermetallic NPs inside a nanoreactor can lower the activation energy of C 2 H 6 and CO 2 , which facilitates the transport/conversion of C 2 *, then significantly improves the dry reforming selectivity of ethane C-C bond breaking over Ni-La@Si catalysts. [Display omitted] • Dry reforming of ethane to syngas is a novel route to co-utilize CO 2 and unconventional gas to get hydrogen energy. • Spatial-chemical bifunctional confinement strategy was offered by Ni-La intermetallic sites within nanocapsule material. • The nanoreactor raised an outstanding catalytic performance in DRE which is the most stable ever reported. • C 2 * is more likely to polymerize than C 1 *, but can be curbed by functional Ni-La nanoreactors. • Physical confinement from the nanocapsule framework plays a more leading role in the anti-coking formation. CO 2 reforming of light alkanes from unconventional gas resources (shale gas/coalbed gas) presents an attractive route to achieve CO 2 utilization and valuable chemical production. However, it remains challenging in both high stability and product selectivity due to the inevitable strong competition between dry reforming and oxidative dehydrogenation pathways. We report here a La modified Ni@SiO 2 nanocapsule as the thermal-catalyst for CO 2 reforming of ethane, achieving complete ethane conversion and remarkable CO 2 conversion of 86.5 %, with stability for more than 200 h experiencing no carbon deposition. Detailed kinetic study, in situ characterizations and DFT calculation results revealed that the formation of NiLa intermetallic sites improved the adsorption of active oxygen species and activation of C 2 H 6 , which stabilized the key intermediate CH 3 CH 2 O* as well as the subsequent C 2 * cracking to CH x (O)*, leading to high selectivity toward syngas. Meanwhile, the removal of carbon deposits on Ni-La 2 O 3 interfaces are faster than Ni surface. The synergism of spatial confinement structure provided by the nanocapsule with sufficient mechanical strength together with the chemical Ni-La 2 O 3 interface of the enwrapped Ni-La mixed metal (oxide) NPs can timely eliminate C 2 * intermediates, which results in the most effective anti-coking ability during ethane reforming. This work highlights a tangible process towards unconventional (C 2+) gas utilization with fine-tunable nanoreactor catalysts. [ABSTRACT FROM AUTHOR]

• Palladium/graphene oxide (Pd/GO) aerogels are synthesized. • Pd/GO aerogels have large surface areas and enrich functionalities. • Pd nanoparticles are uniformly dispersed on the surface of the support. • Pd/GO aerogels have enhanced catalytic performance compared to the Pd/C. In this work, the low-loading (3 wt%) palladium/graphene oxide (Pd/GO) aerogels are facilely prepared via the lyophilisation, vacuum and reduction treatments. The Pd/GO aerogels display enhanced activity and stability in comparison to the commercial Pd/C. The enhancement of electrocatalytic performance can be attributed to the functional groups on the surfaces of the GO support, such as carbonyl and carboxyl groups, which can be tuned to interact with palladium to form active phases for the reaction. In addition, Pd nanoparticles (NPs) remain dispersed in nanoscale on the reacted catalyst. [ABSTRACT FROM AUTHOR]

• Pd/reduced graphene oxide aerogels with large surfaces and wrinkles are synthesized. • Pd/reduced graphene oxide aerogels enrich oxygen-containing functional groups. • A high proportion of Pd2+ is presented on the Pd/reduced graphene oxide aerogels. • Pd/reduced graphene oxide aerogels display an improved activity compared to the Pd/AC. • PdNPs remained well dispersed on the reacted Pd/reduced graphene oxide aerogels. In this work, Pd/reduced graphene oxide (Pd/RGO) aerogels, with large surface areas and wrinkles, are obtained through the lyophilisation, vacuum and reduction treatments. Pd/RGO aerogels exhibit higher catalytic performances and thermal stability in comparison to the reference catalyst Pd/activated carbon (Pd/AC) in the oxidation of benzyl alcohol. The surface analyses indicate that Pd/RGO aerogels possess a higher proportion of Pd2+ than the Pd/AC catalyst. Meanwhile, the oxygen-containing functional groups can modulate the interaction between palladium and the support to form active phases for the reaction. Moreover, Pd nanoparticles (PdNPs) remain well dispersed in nanoscale on the reacted Pd/RGO aerogels. [ABSTRACT FROM AUTHOR]

Pd-Cu-Sn/Al 2 O 3 catalyst eliminates trace CO in hydrogen feed stream, which provides an effective reference for the application of green and sustainable hydrogen fuels. [Display omitted] • Pd-Cu-Sn/Al 2 O 3 exhibits better catalytic performance than Pd-Cu/Al 2 O 3 for CO-PROX. • The incorporation of SnCl 4 enhances the interaction between Sn and Pd, Cu species. • Sn species improve the structure stability of Cu 2 Cl(OH) 3 and water resistance. • More electron-rich Cu+ species in Pd-Cu-Sn/Al 2 O 3 promote the catalytic cycle. A series of Pd-Cu-xSn/Al 2 O 3 catalysts with the low tin content (Sn/Cu atomic ratio = 0.1, 0.25, 0.5) is obtained by the facile impregnation routes and employed for low-temperature CO preferential oxidation (CO-PROX) in H 2 -rich stream. The catalytic performance tests show that the suitable addition of Sn possesses the positive effects on Pd-Cu/Al 2 O 3 for CO-PROX, that is, PC-0.25Sn-Al (Sn/Cu atomic ratio = 0.25) exhibits better catalytic activity and stability at 30 °C. The systematic characterization results demonstrate the moderate incorporation of SnCl 4 to Pd-Cu/Al 2 O 3 drives the generation of SnO 2 , which promotes the strong interaction between Sn species and Pd-Cu/Al 2 O 3. And it is conductive to improving the structure stability of active Cu 2 Cl(OH) 3 species and the better water resistance of PC-0.25Sn-Al. Furthermore, the doping of Sn in PC-0.25Sn-Al may retard the reduction of active Pd species, promoting the absorption/activation and oxidation of CO on active Pd species. Meanwhile, the appropriate amount of Sn in PC-0.25Sn-Al readily provides more electron-rich active Cu+ species in the reaction stream, which is favorable to the reoxidation of Cu+ species by O 2 /active oxygen to Cu2+ species. These will favour the durative catalytic recycle of Pd and Cu species in PC-0.25Sn-Al and the enhancement of its catalytic activity and stability. [ABSTRACT FROM AUTHOR]

Herein, the Co-MMT (Co 3 O 4 -montmorillonite) catalysts were prepared by coordination-deposition (Co(0.015)-MMT-2(CD)) and deposition-precipitation method (Co(0.015)-MMT-2 (DP)) for the N 2 O direct decomposition, respectively. The structure, texture, and surface properties of the catalysts are characterized by XRD, TEM, FT-IR, Raman, XPS, and so on. The results show that compared with Co(0.015)-MMT-2(DP), Co(0.015)-MMT-2(CD) achieves barrier dispersion of active phase (Co 3 O 4) by using the layer structure of montmorillonite and has a smaller Co 3 O 4 crystal size, richer oxygen vacancy and higher content of Co2+ Oh. In addition, the results of DFT calculation and kinetic calculation indicate that Co2+ Oh possesses higher reaction activity than Co2+ Td and Co3+ Oh , and the TOF value of Co(0.015)-MMT-2(CD) at 400 ℃ is 3 times higher than that of Co(0.015)-MMT-2(DP). Therefore, the Co(0.015)-MMT-2(CD) catalyst shows excellent catalytic activity and tolerance to impurity gases (H 2 O, NO, and O 2), and it can maintain 100% conversion at least 50 h for the direct catalytic decomposition of N 2 O. [Display omitted] • MMT layers achieved the barrier and high dispersion of Co 3 O 4. • Co(0.015)-MMT-2(CD) shows excellent N 2 O catalytic decomposition performance. • The Co2+ Oh possesses higher N 2 O decomposition activity than Co2+ Td and Co3+ Oh. [ABSTRACT FROM AUTHOR]

• Eggshell is an effective support to prepare Co 3 O 4 -based catalyst for N 2 O removal. • Co 3 O 4 /eggshell-DP exhibits much higher specific activity than Co 3 O 4. • Co 3 O 4 /eggshell-DP displays outstanding stability and anti-poisoning property. • Co 3 O 4 /eggshell-DP shows a close incorporation between CaCO 3 and Co 3 O 4. Co 3 O 4 shows excellent catalytic activity for N 2 O decomposition, in which it is urgently needed to develop novel efficient catalysts/supports with cheap and environmentally-friendly properties. Herein, Co 3 O 4 nanoparticles decorated eggshell catalysts (Co 3 O 4 /eggshell-GR, Co 3 O 4 /eggshell-IM, and Co 3 O 4 /eggshell-DP) were prepared using simple grinding, impregnation, and deposition-precipitation methods, where waste eggshells were used as an effective support and reaction-promoter. The results indicated that the preparation methods significantly influenced the catalytic activity of Co 3 O 4 /eggshell catalysts; the highest activity was obtained over the Co 3 O 4 /eggshell-DP. The activity of Co 3 O 4 /eggshell-DP was comparable to that of pure Co 3 O 4. More importantly, its specific activity was about 7.3 times that of Co 3 O 4 at 400 °C. The examined Co 3 O 4 /eggshell-DP also displayed outstanding stability and anti-poisoning property in NO, O 2 , and/or H 2 O-containing atmospheres. It was also verified that the excellent activity of Co 3 O 4 /eggshell-DP correlated with the unique structure of the eggshell and the close incorporation between CaCO 3 and Co 3 O 4. The Co 3 O 4 /eggshell-DP catalyst owned abundant Co 3 O 4 nanoparticles, more Co3+ species, and excellent redox performance, promoting the conversion of N 2 O at a lower temperature. The presence of abundant surface basic sites and a larger amount of oxygen vacancies also facilitated the catalytic efficiency of Co 3 O 4 /eggshell-DP. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The deactivation of a commercial Ni/Al2O3 catalyst in the liquid phase hydrogenation of crude 1,4-butanediol aqueous solution was investigated. A significant deactivation trend was observed during the operation time of 5000h. The fresh and deactivated catalysts were characterized by ICP-AES, N2 physisorption, H2-TPR, TEM, TPD, FTIR and XRD. The results indicate that, during the reaction process, the Al2O3 support transforms into its hydrate boehmite (γ-AlO(OH)), which further results in the aggregation of metal Ni, the decrease of BET specific surface area and the reduction of pore volume. The hydration of Al2O3 support is the main reason for the deactivation of Ni/Al2O3 catalyst. The promotion effect of SiO2 on the activity and stability of Ni/Al2O3 catalyst was also investigated. The results suggest that the introduction of SiO2 effectively inhibits the hydration of Al2O3 support and prevents the active decay of Ni/Al2O3 catalyst. [Copyright &y& Elsevier]

Redispersion is an effective method for regeneration of sintered metal-supported catalysts. However, the ambiguous mechanistic understanding hinders the delicate controlling of active metals at the atomic level. Herein, the redispersion mechanism of atomically dispersed Pt on CeO 2 is revealed and manipulated by in situ techniques combining well-designed model catalysts. Pt nanoparticles (NPs) sintered on CeO 2 nano-octahedra under reduction and oxidation conditions, while redispersed on CeO 2 nanocubes above ∼500 °C in an oxidizing atmosphere. The dynamic shrinkage and disappearance of Pt NPs on CeO 2 (100) facets was directly visualized by in situ TEM. The generated atomically dispersed Pt with the square-planar [PtO 4 ] 2+ structure on CeO 2 (100) facets was also confirmed by combining Cs-corrected STEM and spectroscopy techniques. The redispersion and atomic control were ascribed to the high mobility of PtO 2 at high temperatures and its strong binding with square-planar O 4 sites over CeO 2 (100). These understandings are important for the regulation of atomically dispersed platinum catalysts.

The precise identification of postural behavior plays a crucial role in evaluation of animal welfare and captive management. Deep learning technology has been widely used in automatic behavior recognition of wild and domestic fauna species. The Asian slow loris is a group of small, nocturnal primates with a distinctive locomotion mode, and a large number of individuals were confiscated into captive settings due to illegal trade, making the species an ideal as a model for postural behavior monitoring. Captive animals may suffer from being housed in an inappropriate environment and may display abnormal behavior patterns. Traditional data collection methods are time-consuming and laborious, impeding efforts to improve lorises' captive welfare and to develop effective reintroduction strategies. This study established the first human-labeled postural behavior dataset of slow lorises and used deep learning technology to recognize postural behavior based on object detection and semantic segmentation. The precision of the classification based on YOLOv5 reached 95.1%. The Dilated Residual Networks (DRN) feature extraction network showed the best performance in semantic segmentation, and the classification accuracy reached 95.2%. The results imply that computer automatic identification of postural behavior may offer advantages in assessing animal activity and can be applied to other nocturnal taxa., (© 2022. The Author(s).)

Oxygen evolution reaction (OER) is an important half-cell reaction of the electrical water splitting, for its high overpotential associated with sluggish OER kinetics. Therefore, it is critical to develop highly active and durable electrocatalysts to reduce the overpotential. Herein, ultra-small RuO 2 nanoparticles (NPs) supported on onion-like carbon (OLC) and carbon nanotube (CNT) are successfully synthesized by means of wet impregnation combined with annealing treatment, respectively. The microstructure characterization results showed OLC perfect graphitic carbon layer structure, and the RuO 2 NPs supported on the OLC possess larger particle size compared with the RuO 2 NPs supported on the CNT. Moreover, the electronic structure of Ru in RuO 2 /OLC was also optimized by the OLC support to be beneficial for the OER. The OER performance of the catalysts were investigated in 1 M KOH solution. The results show RuO 2 /OLC has a comparable OER activity to the commercial RuO 2 , but a significantly higher mass activity than the commercial RuO 2 . When compared with the RuO 2 /CNT, RuO 2 /OLC not only exhibits lower overpotential and Tafel slop, but also owns more active sites and higher TOF value, indicating the OLC support improved the OER activity of RuO 2 /OLC. Moreover, RuO 2 /OLC showed a superior stability compared with RuO 2 /CNT, which can be attributed to the excellent electrochemical oxidation-resistance of the OLC., (© 2022 IOP Publishing Ltd.)

Interfacial contacts within electrodes largely affect electronic transport and ion migration. Nanoscale electrode materials can achieve high reactivity, but their large interfacial contact areas lead to unavoidable impedance. Herein, a Ti3C2Tx MXene was used to construct a hybrid three-dimensional electrode material with a bilayer feature via a two-step vacuum filtration process. The introduced MXene flakes contributed to the electrode capacity, increased the electronic/ionic conductivity as a conductor and current collector, and enhanced the mechanical behaviour of the electrode by acting as a substrate. Such bilayer hybrid electrode design achieved promising cycling stability, and unlock an electrode architecture that can be applied to a wide range of two-dimensional materials.