Mesoporous TiO₂ whisker was loaded with gold (denoted as Au/T(t), t represents the calcination temperature of support) by deposition-precipitation with urea (DPU) and then used in low-temperature CO ...oxidation. Disparate morphologies were obtained for the gold deposited on different TiO₂ whisker samples while the particle sizes were in a similar range. The better performance of Au/T(600) than Au/T(300) was attributed to the increased contacting area of gold/titania and the strong interaction between gold and well-crystallized suppot surface.
An Au-Cu bimetal catalyst was prepared by deposition-precipitation (urea) of gold and copper species on mesoporous TiO2 and activation with H2. The sample was characterized by N2 ...adsorption/desorption, X-ray diffraction, ultraviolet-visible spectroscopy, and high-resolution transmission electron microscopy. The results showed that the Au and Cu species formed an Au-Cu alloy and were well dispersed on the mesoporous TiO2. According to CO oxidation test results, it was found that the catalytic activity of gold was enhanced by copper. The Au-Cu bimetal catalyst supported on mesoporous TiO2 showed better catalytic stability in CO oxidation than the Au catalyst supported on mesoporous TiO2 and the nonporous TiO2-supported catalysts. This may be related to the effects of Au-Cu alloying and the mesostructure of TiO2.
将金、铜前驱体沉积沉淀到介孔氧化钛材料上, 再经氢气活化后制备了双金属催化剂 Au-Cu/TiO2, 并采用 N2 吸附/脱附、X 射线粉末衍射、紫外-可见光谱和高分辨透射电镜等对样品进行了表征. 结果显示, 金和铜形成合金相, 且良好地分散在介孔氧化钛上. CO 氧化反应结果表明, Cu 可以提高 Au 催化剂的催化性能, Au-Cu/TiO2 催化剂比 Au/TiO2 和无孔氧化钛负载的 Au 催化剂具有更好的 CO 催化氧化稳定性. 这可能与 Au, Cu 合金化和氧化钛的介孔结构有关.
The catalytic stability of a gold-based catalyst can be significantly improved by the effects of both Au-Cu alloying and the mesostructure of TiO2.
Plants perceive various external and internal signals to self-modulate biological processes through members of the receptor-like kinase (RLK) family, among which Catharanthus roseus receptor-like ...kinase 1-like (CrRLK1L) proteins with their ligands, rapid alkalinization factor (RALF) peptides, have attracted considerable interest. FERONIA (FER), a CrRLK1L member, was initially reported to act as a major plant cell growth modulator in distinct tissues. Subsequently, the RALF–FER pathway was confirmed to function as an essential regulator of plant stress responses, including but not limited to immune responses. Furthermore, the RALF–FER pathway modulates immune responses and cell growth in a context-specific manner, and the vital roles of this pathway are beginning to be appreciated in crop species. The recent remarkable advances in understanding the functions and molecular mechanisms of the RALF–FER pathway have also raised many interesting questions that need to be answered in the future. This review mainly focuses on the roles of FER and other CrRLK1L members in modulating immune responses in the context of cell growth in response to their RALF peptide ligands and presents a brief outlook for future research.
Plants use receptor-like kinases to perceive and respond to various growth and stress signals. This review discusses the vital roles of the receptor kinase FERONIA in regulating plant growth and immune responses in response to its ligands, RALF peptides, in Arabidopsis and crop species. It also raises interesting questions that need to be answered in the future.
CO2 removal (or separation) is the key step for biogas upgrading. This research aims to investigate aqueous solutions of amino acid ionic liquids to achieve effective CO2 separation. In this work, ...three cholinium-based amino acid ionic liquids (ChoAAs) (i.e. cholinium glycinate (ChoGly), cholinium alaninate (ChoAla) and cholinium prolinate (ChoPro)) were synthesized and characterized. The effect of water on the viscosity, CO2 absorption loading (m and α) and apparent absorption rate constant was systematically studied. The CO2 absorption mechanism in the aqueous solution of ChoGly was explored by 13C Nuclear Magnetic Resonance (NMR). The results demonstrate that the absorption loading (m) and viscosity increase with increasing IL concentration, while the apparent absorption rate constant decreases. The absorption loading decreased with increasing temperature. The CO2 absorption mechanism in the aqueous ChoGly solution started with the chemical reaction to form carbamate at low absorption loading (α), and followed by the hydrolysis of carbamate and CO2 hydration reaction at high absorption loading (α). Moreover, the aqueous solution with 5 wt % ChoGly showed the highest regeneration efficiency, and the absorption and regeneration performance of the aqueous solution of ChoGly was compared with commercial CO2 absorbents with promising results.
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•H2O interacts strongly with ChoPro/PEG200 in the hybrid absorbent.•The formation of carbamate is dominated especially at low CO2 pressure.•The presence of H2O results in the ...formation of bicarbonate.•The hybrid absorbent has advantages on the CO2 solubility and absorption enthalpy.
Developing novel hybrid absorbents is essential for CO2 separation. In this study, the density and viscosity of a hybrid absorbent (choline-2-pyrrolidine-carboxylic acid/polyethylene glycol/water (ChoPro/PEG200/H2O)) were measured experimentally, and its CO2 solubility was also determined. The excess mole volume and excess Gibbs energy of activation of the hybrid absorbent were further estimated to understand the molecular structure and interactions between ChoPro/PEG200 and H2O. The CO2 solubilities in ChoPro/PEG200 and ChoPro/H2O were analyzed and described using the Redlich–Kwong non-random-two-liquid (RK-NRTL) model. Furthermore, the CO2 solubility in the hybrid absorbent was predicted using the RK-NRTL model and was compared with the new experimental results for verification. The effect of H2O on the CO2 absorption performance was further analyzed. The performance and cost of the hybrid absorbent were compared with those of other commercialized CO2 absorbents. In addition, the recyclability of the hybrid absorbent for CO2 separation was studied. The results of this study indicated that the hybrid absorbent could be promising for CO2 separation.
In order to meet climate goals, both CO2 capture and storage (CCS) and CO2 capture and utilization (CCU) have been identified as increasingly important technologies for mitigating CO2 emissions that ...are difficult to avoid. In this work, the CO2 utilization, or more specifically, the CO2 conversion to fuels and urea, considering the large demand for CO2, as well as the CO2 mineralization are surveyed and reviewed. The content of this review includes technologies – all the way from the laboratory studies to the industrial applications – their current status, and future potential. CCS is included for a comparison concerning the costs. Also, aspects as the CO2 impurities and the effect of it as well as various requirements concerning the CO2 impurity are included. Many recent studies show that CCU, especially CO2 conversion to fuels, will play an essential role in mitigating CO2 emissions, while developed methods and technologies are not yet mature. More research work needs to be conducted to improve the process efficiency via developing catalysts and reducing the cost of producing H2 that is used as a reactant for fuel synthesis. Moreover, current literature also shows that impurities will affect the process of both CCS and CCU, while the work of studying their influence, especially on CCU, is still scarce. The cost of CCS has been estimated combined with impurities, while studies on cost estimation for CCU are still limited, and the cost, in general, is relatively high with the currently available technologies.
•CCU plays an essential role in mitigating CO2 emissions, while development is immature.•The costs of CCS and CCU are relatively high compared to the present price of emitting CO2 emissions.•The impurities will affect the process of both CCS and CCU, but the work, especially on CCU, is still scarce.
To develop polyethylene glycol 200 (PEG200) and aqueous PEG200 solutions (PEG200/H2O) as solvents for CO2 separation, in this study, the available thermo-physical properties of PEG200 and PEG200/H2O ...measured experimentally were surveyed, evaluated, and correlated with empirical equations. The solubility of CO2 in PEG200 was also surveyed, evaluated and described with the Henry's law with the Poynting correction, while the solubilities of CH4 and N2 in PEG200 were determined experimentally and then described with the Henry's law. The CO2, CH4 and N2 solubilities in PEG200/H2O were measured and described with the Redlich–Kwong Nonrandom-Two-Liquid (RK-NRTL) model. In addition, the performances of PEG200, PEG200/H2O and other commercialized physical solvents for CO2 separation were discussed based on the properties, and the biogas upgrading was chosen as the example to quantitatively evaluate the performances of PEG200 and PEG200/H2O with process simulation and compared with the high pressure water scrubbing (HPWS). It shows that the total energy usage and the amount of recirculated solvent for biogas upgrading can decrease by 9.1% and 26.5%, respectively, when H2O is replaced by PEG200 completely.
Constructing architectures with hierarchical porosity has been widely considered as the most efficient way to bypass the problems related to slow mass transfer and inaccessibility of internal space ...in MOFs. Now, a crystal‐growth‐dominated strategy is proposed to fabricate hierarchically porous MOFs (HP‐MOFs). When the crystal growth is dominated by the monomer attachment, the aggregation of nonionic surfactant or polymer can be easily captured and released during the crystal growth process, resulting in the formation and ordering hierarchical pores along the radial direction. Owing to the accelerated mass diffusion and more exposed active sites of this design, HP‐MOFs exhibited an enhanced catalytic efficiency in styrene oxidation.
HP‐MOFs: A crystal‐growth‐dominated synthetic strategy is proposed to achieve hierarchically porous metal–organic frameworks. The HP‐MOFs have a wide pore size distribution and an orderly distributed porosity in the radial direction. Benefitting from the hierarchical architecture, HP‐MOFs exhibit enhanced catalytic efficiency in styrene oxidation.
It has great significance to investigate the degradation of aromatic contaminants as they are highly carcinogenic and nondegradable pollutants in drinking water. In this paper, the mineralization ...orders of the representative nitro/chloro/methyl/amino-aromatic contaminants with oxidants (·OH, H2O2, ·O−, O2,O3) in advanced oxidation processes (AOPs) are investigated based on the calculated standard molar Gibbs free energy changes of reaction (Δr G m 0) and the results are consistent with those from previous experimental results, electrophilic substitution orientation rules of the Hammett equation, and predicted results with a quantitative structure−activity relationship (QSAR). In addition, the quantitative function relationship between the degradation rate (r) of the aromatic contaminants and the thermodynamic driving force (Δr G m 0) is analyzed in order to investigate the degradation kinetics more rigorously.
Serotonin (5-hydroxytryptamine, 5-HT) is an essential neurotransmitter involved in regulating various behaviors in plant-parasitic nematodes (PPNs), including locomotion, egg laying, feeding, and ...mating. However, the functional role of serotonin in root-knot nematode invasion of host plants and the molecular mechanisms underlying feeding behavior remain poorly understood. In this study, we tested the effects of exogenous serotonin and the pharmacological compounds fluoxetine and methiothepin on the feeding behaviors of Meloidogyne graminicola. Our results suggested that M. graminicola possesses an endogenous serotonin signaling pathway and that serotonin plays a crucial role in modulating feeding behaviors in M. graminicola second stage juveniles (J2). We also identified and cloned the serotonin synthesis enzyme tryptophan hydroxylase (Mg-tph-1) in M. graminicola and investigated the role of endogenous serotonin by generating RNA interference nematodes in Mg-tph-1. As a result, silencing Mg-tph-1 substantially reduced nematode invasion, development, and reproduction. According to the immunostaining results, we speculated that these serotonin immunoreactive cells near the nerve ring in M. graminicola are likely homologous to Caenorhabditis elegans ADFs, NSMs, and RIH serotonergic neurons. Furthermore, we investigated the impact of phytoserotonin on nematode invasion and development in rice by overexpressing OsTDC-3 or supplementing rice plants with tryptamine and found that an increase in phytoserotonin increases nematode pathogenicity. Overall, our study provides insights into the essential role of serotonin in M. graminicola host plant parasitism and proposes that the serotonergic signaling pathway could be a potential target for controlling PPNs.
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