RESUMO
Bi2O3 catalyst with Bi-O bond crystal structure has more active sites, which shows better CO2 catalytic performance than pure Bi catalysts in many catalytic reactions. How to strengthen the Bi-O bond in Bi2O3 to obtain higher selectivity and catalytic activity is a problem worthy of consideration. Here, we develop a N2 pre-reduced spherical Bi2O3/ATO catalyst that has a high formate Faradaic efficiency of 92.7%, which is superior to the existing tin oxide catalyst. Detailed electrocatalytic analysis shows that N2 pre-reduction and spherical structure are helpful for Sn to stabilize the oxidation state of Bi, thus retaining part of the Bi-O structure. The existence of the Bi-O structure can reduce the energy barrier of the CO2 production *OCHO reaction and promote the reaction rate of the CO2-*OCHO-HCOOH path, thus promoting the formation of formate.
Assuntos
Dióxido de Carbono , Formiatos , CatáliseRESUMO
Non-aqueous absorbents (NAAs) have attracted increasing attention for CO2 capture because of their great energy-saving potential. Primary diamines which can provide high CO2 absorption loading are promising candidates for formulating NAAs but suffer disadvantages in regenerability. In this study, a promising strategy that using tertiary amines (TAs) as proton-transfer mediators was proposed to enhance the regenerability of an aminoethylethanolamine (AEEA, diamine)/dimethyl sulfoxide (DMSO) (A/D) NAA. Surprisingly, some employed TAs such as N,N-diethylaminoethanol (DEEA), N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA), 3-dimethylamino-1-propanol (3DMA1P), and N,N-dimethylethanolamine (DMEA) enhanced not only the regenerability of the A/D NAA but also the CO2 absorption performance. Specifically, the CO2 absorption loading and cyclic loading were increased by about 12.7% and 15.5%-22.7%, respectively. The TA-enhanced CO2 capture mechanism was comprehensively explored via nuclear magnetic resonance technique and quantum chemical calculations. During CO2 absorption, the TA acted as an ultimate proton acceptor for AEEA-zwitterion and enabled more AEEA to form carbamate species (AEEACOO-) to store CO2, thus enhancing CO2 absorption. For CO2 desorption, the TA first provided protons directly to AEEACOO- as a proton donor; moreover, it functioned as a proton carrier and facilitated the low-energy step-wise proton transfer from protonated AEEA to AEEACOO-. Consequently, the presence of TA made it easier for AEEACOO- to obtain protons to decompose, resulting in enhanced CO2 desorption. In a word, introducing the TA as a proton-transfer mediator into the A/D NAA enhanced both the CO2 absorption performance and the regenerability, which was an efficient way to "kill two birds with one stone".
Assuntos
Dióxido de Carbono , Etanolaminas , Prótons , Aminas , DiaminasRESUMO
To address the problems of high viscosity and difficult regeneration of the rich phase solution, a dual-functionalized ionic liquid ([DETAH][Tz]) was dissolved into a 1-propanol-water solvent to form a novel biphasic solvent for CO2 capture. The rich phase kept 96% of the total CO2 loading (1.713 mol mol-1) but only 44% of the total volume, and its viscosity was only 2.57 mPa s. As a regeneration promoter, 1-propanol helped the rich phase to maintain 90% of its initial loading after fifth regeneration. The high number of amine functional groups into [DETAH]+ and the equimolar reaction of [Tz]- provided the high CO2 loading, while [Tz]-H and 1-propanol ensured the high regeneration efficiency of the rich solution by enhancing the hydrolysis of RNCOO- to form HCO3-/CO32- and propyl carbonate. Due to a stronger polar and an aggregation of the CO2 absorption products in water, the CO2 products were enriched into the lower water phase while most of the 1-propanol was in the upper phase. The heat duty of [DETAH][Tz]-1-propanol-water was approximately 29.93% lower than [DETAH][Tz]-water (2.84 GJ ton-1 CO2) and 47.63% lower than MEA (3.80 GJ ton-1 CO2), which would be a promising candidate for CO2 capture.
Assuntos
Dióxido de Carbono , Líquidos Iônicos , Aminas , Solventes , ÁguaRESUMO
VGLL4, a member of the Vestigial-like (VGLL) proteins, has been reported to be dysregulated in several cancer types. However, its function in esophageal squamous cell carcinoma (ESCC) remains poorly understood. Here, it was found that the expression level of VGLL4 was decreased in ESCC tissues. Moreover, forced expression of VGLL4 in ESCC cells inhibited cell growth and migration, while knockdown of VGLL4 expression promoted the tumorigenecity of ESCC cells. Mechanistically, VGLL4 regulated the growth and motility of ESCC cells through downregulating the expression of connective tissue growth factor (CTGF), a known oncogene in the progression of ESCC. Taken together, our study suggested that downregulation of VGLL4 was very important in the progression of ESCC, and restoring the function of VGLL4 might be a promising therapeutic strategy for ESCC.
Assuntos
Carcinogênese/genética , Carcinoma de Células Escamosas/genética , Proliferação de Células , Neoplasias Esofágicas/genética , Fatores de Transcrição/biossíntese , Animais , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Progressão da Doença , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Transdução de Sinais , Fatores de Transcrição/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Though the mechanism of MEA-CO2 system has been widely studied, there is few literature on the detailed mechanism of CO2 capture into MEA solution with different CO2 loading during absorption/desorption processes. To get a clear picture of the process mechanism, (13)C nuclear magnetic resonance (NMR) was used to analyze the reaction intermediates under different CO2 loadings and detailed mechanism on CO2 absorption and desorption in MEA was evaluated in this work. The results demonstrated that the CO2 absorption in MEA started with the formation of carbamate according to the zwitterion mechanism, followed by the hydration of CO2 to form HCO3(-)/CO3(2-), and accompanied by the hydrolysis of carbamate. It is interesting to find that the existence of carbamate will be influenced by CO2 loading and that it is rather unstable at high CO2 loading. At low CO2 loading, carbamate is formed fast by the reaction between CO2 and MEA. At high CO2 loading, it is formed by the reaction of CO3(-)/CO3(2-) with MEA, and the formed carbamate can be easily hydrolyzed by H(+). Moreover, CO2 desorption from the CO2-saturated MEA solution was proved to be a reverse process of absorption. Initially, some HCO3(-) were heated to release CO2 and other HCO3(-) were reacted with carbamic acid (MEAH(+)) to form carbamate, and the carbamate was then decomposed to MEA and CO2.
Assuntos
Dióxido de Carbono/química , Etanolamina/análise , Absorção Fisico-Química , Adsorção , Aminas/química , Carbamatos/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Hidrólise , SoluçõesRESUMO
TiO2-based photocatalysts are a potential technology for removing indoor formaldehyde (CHOH) owing to their strong photooxidation ability. However, their photooxidation performance is generally weakened when suffering from the competitive adsorption of H2O. In a method inspired by the oxygen evolution reaction (OER) to generate intermediates with hydroxyl radicals on the anode electrode catalysts, an electric field was employed in this research and applied to the photooxidation of CHOH to prevent the competitive adsorption of H2O. Additionally, 0.5-5% Fe2O3 decorated TiO2 was employed to improve the photoelectrocatalytic activity. The influence of an electric field on hydroxyl-radical production was investigated by both density functional theory (DFT) with direct-imposed dipole momentum and photoelectrocatalytic experimental tests. The surface characterization of the photocatalysts, including transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR), was conducted. DFT results show that a positive electric field with a strength of 0.05 Å/V was more favorable to produce hydroxyl on Fe2O3/TiO2(010) than was a negative electric field. Fe2O3 decoration can significantly boost hydroxyl formation, resulting from a decrease in the binding energy between the Fe of Fe2O3 and the oxygen and hydrogen atoms of H2O. The dissociated hydrogen atom of the H2O preferentially remained on the catalysts' surface rather than being released into the gas flow. The experimental results demonstrated that applying 150 V could not directly enhance the photooxidation of CHOH by either TiO2 or Fe2O3/TiO2 but that it could relieve the H2O inhibitory effect by more than 10% on the Fe2O3/TiO2.
Assuntos
Titânio , Água , Catálise , FormaldeídoRESUMO
Amino-functionalized ionic liquid biphasic solvents present excellent absorption capacity, regeneration ability, and energy consumption savings, which make them a possible candidate for CO2 capture. The kinetics and regeneration heat duty of the [TETAH][Lys]-ethanol-water system capturing CO2 were investigated in this work. The mass transfer and kinetic parameters, including the overall reaction rate constant (kov), the reaction rate constant (k2), and the enhancement factor (E), were assessed at diverse concentrations and temperatures. At 303.15 K, the k2 of CO2 capture into the [TETAH][Lys]-ethanol-water solution was 58,907.30 m3 kmol-1 s-1. The Arrhenius equation was introduced to evaluate the relations between k2 and the reaction temperature, which can be presented as [Formula: see text] The regeneration heat duty of the novel biphasic solvent was 35.5 and 62.39% lower than those of [TETAH][Lys]-water and the benchmark monoethanolamine solution, respectively. An efficient absorption performance and lower energy requirement indicate the great potential for this application.
Assuntos
Dióxido de Carbono , Líquidos Iônicos , Temperatura Alta , Cinética , SolventesRESUMO
Sustainable management of dyeing industry is of paramount importance in order to minimize resource consumption and reduce related environmental impacts. Herein, an environmental study is conducted wherein life cycle assessment (LCA) is applied to a two-scenario process for Disperse blue 60 production with short and long processing chains with different (a) material types, (b) consumptions, (c) processes, and (d) functional units with yields of 300 t/a. The most important influenced substances of the two scenarios were sodium cyanide and electricity next. Results proved that the largest damage of the dye production was attributed to resources and reached 46 and 62 kPt in the two scenarios. Compared with the conventional coal-fired power generation, damaged values of electricity from nature gas (NG) could reduce from 102 to 86 kPt in scenarios 1 and from 123 to 104 kPt in scenarios 2, respectively. When the electricity switched from NG to solar power, the values of the two scenarios could further decrease by 17 and 27 kPt, respectively. Therefore, the process of scenario 1 with the short process chain was more environmentally friendly for the production of Disperse blue 60 owing to the more efficient process and lower resource consumption. Graphic abstract.
Assuntos
Carvão Mineral , Meio Ambiente , Eletricidade , Gás NaturalRESUMO
Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer death worldwide. Lung adenocarcinoma is the main tumor type of NSCLC. Recent advances in the molecular characterization and personalized therapies have improved NSCLC patient prognosis. Previous studies showed that protein tyrosine kinase 7 (PTK7) plays an important role in human cancers. However, the role of PTK7 has not been investigated. PTK7 expression was assessed by immunohistochemistry in 95 patients with lung adenocarcinoma. Correlations of PTK7 expression levels with clinicopathological parameters, EGFR mutation and EML4-ALK fusion were examined. Positive PTK7 expression was detected in 47.4% of lung adenocarcinoma. PTK7 expression was associated with gender (P=0.024), lymph node metastasis (P<0.001), ALK mutation (P=0.050), and EGFR mutations (P=0.014). No significant association was found between PTK7 expression and age (P=0.831), differentiation (P=0.494), adenocarcinoma subtype (P=0.098) and Ki67 (P=0.473). Our data suggest that PTK7 plays an oncogenic role in lung adenocarcinoma and may be a molecular marker for lymph node metastasis.
Assuntos
Adenocarcinoma de Pulmão/patologia , Moléculas de Adesão Celular/metabolismo , Receptores ErbB/genética , Metástase Linfática , Proteínas de Fusão Oncogênica/genética , Receptores Proteína Tirosina Quinases/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Moléculas de Adesão Celular/genética , Receptores ErbB/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas de Fusão Oncogênica/metabolismo , Oncogenes , Receptores Proteína Tirosina Quinases/genéticaRESUMO
Highly active Fe/Ni bimetallic nanocomposites were prepared by using the liquid-phase reduction method, and they were proven to be effective for Cr(VI) removal coupled with US irradiation. The US-assisted Fe/Ni bimetallic system could maintain a good performance for Cr(VI) removal at a wide pH range of 3-9. Based on the characterization of the Fe/Ni nanoparticles before and after reaction, the high efficiency of the mixed system could attribute to the synergistic effects of the catalysis of Ni(0) and US cavitation. Ni(0) could facilitate the Cr(VI) reduction through electron transfer and catalytic hydrogenation. Meanwhile, US could fluidize the Fe/Ni nanoparticles to increase the actual reactive surface area and clean off the co-precipitated Fe(III)-Cr(III) hydroxides to maintain the active sites on the surface of the Fe/Ni nanoparticles. Thus, compared with shaking, the US-assisted Fe/Ni system was more efficient on Cr(VI) removal, which achieved 94.7% removal efficiency of Cr(VI) within 10 min. The pseudo-first-order rate constant (kobs) in US-assisted Fe/Ni system (0.5075 min(-1)) was over 5 times higher than that under shaking (0.0972 min(-1)). Moreover, the Fe/Ni nanoparticles still have a good performance under US irradiation after 26 days aging as well as regeneration.
Assuntos
Cromo/análise , Ferro/química , Nanopartículas/química , Níquel/química , Ondas Ultrassônicas , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Catálise , Cromo/química , Modelos Teóricos , Oxirredução , Propriedades de Superfície , Poluentes Químicos da Água/químicaRESUMO
New materials of Fe3O4 magnetic microspheres were functionalized with carboxyl and prepared for carbonic anhydrase (CA) immobilization to capture CO2. The optimum conditions for immobilization, such as carrier dose, enzyme dose, pH, shaking speed, temperature and contact time, were determined. The pH and thermal stability of the free and the immobilized CA were compared. The results presented that the immobilized CA had a better enzyme activity, a higher pH and thermal stability than that of the free CA. Meanwhile, CO2 capture was respectively enhanced by the free and the immobilized CA in tris(hydroxymethyl) aminomethane (Tris) buffer solution. Moreover, the immobilized CA maintained 58.5% of its initial catalytic ability even after ten recovery cycles due to the protest of the magnetic microspheres. All the results confirmed the potential use of the carboxyl-functionalized Fe3O4 magnetic microspheres immobilized CA to remove CO2 from air or flue gas.