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1.
J Environ Sci (China) ; 150: 267-276, 2025 Apr.
Article in English | MEDLINE | ID: mdl-39306402

ABSTRACT

The electrocatalytic reduction of carbon dioxide (CO2ER) into formate presents a compelling solution for mitigating dependence on fossil energy and green utilization of CO2. Bismuth (Bi) has been gaining recognition as a promising catalyst material for the CO2ER to formate. The performance of Bi catalysts (named as Bi-V) can be significantly improved when they possess single metal atom vacancy. However, creating larger-sized metal atom vacancies within Bi catalysts remains a significant challenge. In this work, Bi nanosheets with dual VBi0 vacancy (Bi-DV) were synthesized utilizing in situ electrochemical transformation, using BiOBr nanosheets with triple vacancy associates (VBi″'VO··VBi″', VBi″' and VO·· denote the Bi3+ and O2- vacancy, respectively) as a template. The obtained Bi-DV achieved higher CO2ER activity than Bi-V, showing Faradaic efficiency for formate production of >92% from -0.9 to -1.2 VRHE in an H-type cell, and the partial current density of formate reached up to 755 mA/cm2 in a flow cell. The comprehensive characterizations coupled with density functional theory calculations demonstrate that the dual VBi0 vacancy on the surface of Bi-DV expedite the reaction kinetics toward CO2ER, by reducing the thermodynamic barrier of *OCHO intermediate formation. This research provides critical insights into the potential of large atom vacancies to enhance electrocatalysis performance.


Subject(s)
Bismuth , Carbon Dioxide , Electrochemical Techniques , Formates , Nanostructures , Bismuth/chemistry , Formates/chemistry , Carbon Dioxide/chemistry , Nanostructures/chemistry , Catalysis , Electrochemical Techniques/methods , Oxidation-Reduction , Models, Chemical
2.
J Environ Sci (China) ; 150: 440-450, 2025 Apr.
Article in English | MEDLINE | ID: mdl-39306419

ABSTRACT

Phase change absorbents based on amine chemical absorption for CO2 capture exhibit energy-saving potential, but generally suffer from difficulties in CO2 regeneration. Alcohol, characterized as a protic reagent with a low dielectric constant, can provide free protons to the rich phase of the absorbent, thereby facilitating CO2 regeneration. In this investigation, N-aminoethylpiperazine (AEP)/sulfolane/H2O was employed as the liquid-liquid phase change absorbent, with alcohol serving as the regulator. First, appropriate ion pair models were constructed to simulate the solvent effect of the CO2 products in different alcohol solutions. The results demonstrated that these ion pair products reached the maximum solvation-free energy (ΔEsolvation) in the rich phase containing ethanol (EtOH). Desorption experiment results validated that the inclusion of EtOH led to a maximum regeneration rate of 0.00763 mol/min, thus confirming EtOH's suitability as the preferred regulator. Quantum chemical calculations and 13C NMR characterization were performed, revealing that the addition of EtOH resulted in the partial conversion of AEP-carbamate (AEPCOO-) into a new product known as ethyl carbonate (C2H5OCOO-), which enhanced the regeneration reactivity. In addition, the decomposition paths of different CO2 products were simulated visually, and every reaction's activation energy (ΔEact) was calculated. Remarkably, the ΔEact for the decomposition of C2H5OCOO- (9.465 kJ/mol) was lower than that of the AEPCOO- (26.163 kJ/mol), implying that CO2 was more likely to be released. Finally, the regeneration energy consumption of the alcohol-regulated absorbent was estimated to be only 1.92 GJ/ton CO2, which had excellent energy-saving potential.


Subject(s)
Carbon Dioxide , Carbon Dioxide/chemistry , Ethanol/chemistry , Models, Chemical
3.
J Environ Sci (China) ; 150: 622-631, 2025 Apr.
Article in English | MEDLINE | ID: mdl-39306434

ABSTRACT

The non-aqueous solid-liquid biphasic solvent of 2-amino-2-methyl-1-propanol (AMP)/piperazine (PZ)/dipropylene glycol dimethyl ether (DME) features a high CO2 absorption loading, favorable phase separation behavior and high regeneration efficiency. Different with the liquid-liquid phase change solvent, the reaction kinetics of CO2 capture into solid-liquid biphasic solvent was rarely studied. In the present work, the reaction kinetics of CO2 absorption into AMP/PZ/DME solid-liquid biphasic solvent was investigated into the double stirred kettle reactor. The absorption reaction followed a pseudo-first-order kinetic model according to the zwitterion mechanism. The overall reaction rate constant (kov) and the enhancement factor (E) of CO2 absorption both increased with increasing temperature. The total mass transfer resistance of the absorbent decreased with increasing temperature and increased with increasing absorption loading, so the higher reaction temperature was conducive to the absorption, and the liquid phase mass transfer resistance was the main factor affecting the absorption rate.


Subject(s)
Carbon Dioxide , Solvents , Carbon Dioxide/chemistry , Kinetics , Solvents/chemistry , Models, Chemical , Piperazines/chemistry , Piperazine/chemistry , Propanolamines
4.
J Environ Sci (China) ; 140: 146-156, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38331496

ABSTRACT

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".


Subject(s)
Carbon Dioxide , Ethanolamines , Protons , Amines , Diamines
5.
J Environ Sci (China) ; 140: 331-340, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38331512

ABSTRACT

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.


Subject(s)
Carbon Dioxide , Formates , Catalysis
6.
Environ Sci Pollut Res Int ; 29(10): 13805-13821, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34599445

ABSTRACT

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.


Subject(s)
Titanium , Water , Catalysis , Formaldehyde
7.
Environ Sci Pollut Res Int ; 27(21): 26965-26973, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32385823

ABSTRACT

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.


Subject(s)
Carbon Dioxide , Ionic Liquids , Hot Temperature , Kinetics , Solvents
8.
Environ Sci Technol ; 54(10): 6281-6288, 2020 05 19.
Article in English | MEDLINE | ID: mdl-32320224

ABSTRACT

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.


Subject(s)
Carbon Dioxide , Ionic Liquids , Amines , Solvents , Water
9.
Environ Sci Pollut Res Int ; 27(20): 25197-25208, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32347496

ABSTRACT

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.


Subject(s)
Coal , Environment , Electricity , Natural Gas
10.
Histol Histopathol ; 35(5): 489-495, 2020 May.
Article in English | MEDLINE | ID: mdl-31701509

ABSTRACT

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.


Subject(s)
Adenocarcinoma of Lung/pathology , Cell Adhesion Molecules/metabolism , ErbB Receptors/genetics , Lymphatic Metastasis , Oncogene Proteins, Fusion/genetics , Receptor Protein-Tyrosine Kinases/metabolism , Adult , Aged , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Adhesion Molecules/genetics , ErbB Receptors/metabolism , Female , Gene Expression Profiling , Humans , Immunohistochemistry , Lung Neoplasms/pathology , Male , Middle Aged , Mutation , Oncogene Proteins, Fusion/metabolism , Oncogenes , Receptor Protein-Tyrosine Kinases/genetics
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