查找使用阿拉丁产品的科研文献

Effects of Mo2C loading and H2S concentration on Mo2C/Al2O3 catalyst applied in sulfur-resistant methanation

Baowei Wang,Chengyu Wang,Wenxian Yu

Mo 2 C/Al 2 O 3 catalyst was prepared by the impregnation method with urotropine and ammonium paramolybdate. The catalytic effect of Mo 2 C as a typical transition-metal carbide in sulfur-resistant methanation was studied. The catalysts prepared were characterized by N 2 adsorption–desorption, X-ray diffraction, transmission electron microscopy, H 2 -temperature-programmed reduction, and Raman spectra, with the results confirming the formation of β-molybdenum carbide on the surface of the catalysts. Studies on catalysts with different loading doses indicate that the optimal loading of Mo 2 C/Al 2 O 3 is about 15 wt.%, which enables CO conversion rate of up to 47%, with methane selectivity of up to 53%. This work further explored the effect of different concentrations of H 2 S in the raw gas on the performance of the catalyst, with the results showing that high concentration of H 2 S (>1500 ppm) can lead to sulfuration of active species on the catalyst, while resulting in a decrease in the catalytic activity.

Efficient Regeneration of SO2-Absorbed Functional Ionic Liquids with H2S via the Liquid-Phase Claus Reaction

Qi Zhang,Yucui Hou,Shuhang Ren,Kai Zhang,Weize Wu

Functional ionic liquids (ILs), which have high absorption capacities of low-concentration SO2 through chemical interaction, have been widely studied. However, the absorbed SO2 in functional ILs is normally desorbed with high-temperature and steaming treatment, which is harmful to the stability of absorbents and causes high-energy consumption. In this work, functional ILs (monoethanolaminium lactate-[MEA]L, 1,1,3,3-tetramethylguanidinium lactate-[TMG]L, tetraethylammonium lactate-[N2222]L) mixed with ethylene glycol (EG) or H2O were used to capture low-concentration SO2, and then H2S was added to regenerate the absorbents via the liquid-phase Claus reaction. It was found that the reaction of H2S with SO2 in the absorbents proceeded fast and the absorbed SO2 was almost completely converted to solid sulfur (S8) under mild conditions without the addition of any catalysts. The effects of temperature, H2S initial pressure, and solvent on the Claus reaction in the functional ILs were investigated, and the optimal reaction conditions were obtained. The recycle experiments showed that the activity of the functional ILs for the Claus reaction was not decreased after being reused three times. The Claus reaction between H2S and SO2 in functional ILs provides a promising method for the efficient regeneration of functional ILs and SO2 resource utilization.

Mechanisms of mercury transformation over α-Fe2O3(0 0 1) in the presence of HCl and/or H2S

Yu Chen,Xin Guo,Fan Wu,Yu Huang,Zhanchi Yin

Hematite (α-Fe 2 O 3 ) has been proved to be a promising sorbent for mercury removal in various situations. The mercury removal performance of α-Fe 2 O 3 was investigated using a simulated coal gasification syngas containing Hg 0 , N 2 , HCl, and/or H 2 S, a series of experiments were designed with HCl and H 2 S separately and both employed. For a better understanding in the interaction between HCl and H 2 S in mercury removal, the differences in mercury oxidation were demonstrated on the basis of density functional theory calculations. The rate-limiting step in HgCl 2 formation is Hg 0  → HgCl with the energy barrier of 139.47 kJ/mol, but for H 2 S in mercury oxidation, the generation of active sulfur species is the key step and the rate-limiting step is detachment of second H with an energy barrier of 57.53 kJ/mol. Experimental results point that HCl has inhibition on H 2 S for mercury removal, it may be ascribed to the competition of active Fe sites on Fe 2 O 3 . Conversely, HCl contributes to the mercury oxidation at high temperature while H 2 S has a limit effect at elevated temperature.

Effect of preparation conditions on MnxOy/Al2O3 sorbent for H2S removal from high-temperature synthesis gas

Haifeng Li,Sheng Su,Song Hu,Kai Xu,Long Jiang,Yi Wang,Jun Xu,Jun Xiang

A series of Mn x O y /Al 2 O 3 sorbents with different tissue and chemical structures were prepared by repeated incipient wet impregnation method with different calcination conditions, including calcination temperature from 500 °C to 900 °C and calcination time from 3 h to 9 h. The H 2 S absorption performances of the prepared sorbents were investigated by a model synthesis gas containing 2000 mg/m 3 H 2 S at 850 °C. The chemical and physical structures of the samples were characterized by Brunauer–Emmett–Teller, X-ray diffraction and scanning electron microscopy techniques to obtain fundamental information about the deactivation of Mn x O y /Al 2 O 3 sorbents during desulfurization–regeneration cycles. Results showed that the structural features of the sorbents at high reaction temperature played an important role in the stability of desulfurization performance. The analysis of the characteristics of the sorbents indicated that the sorbents obtained stabilized chemical and physical structures during desulfurization–regeneration cycles when the calcination temperature was 900 °C and the calcination time was above 6 h. The sorbent suffered serious deactivation during five successive desulfurization–regeneration cycles when the calcination temperature of sorbents was below 850 °C. The sulfur capacity decreasing of Mn x O y /Al 2 O 3 sorbents may probably be attributed to a part of Mn x O y covered by Al 2 O 3 , which can un-sulfide during adsorption process. The coverage of active phase Mn x O y may be caused by the shrinking and disappearing of some micropores, and phase transformation of Al 2 O 3 , as well as the transformation of MnAl 2 O 4 lead to a part of Mn x O y on the sorbents being covered by alumina.

l-Cysteine enhances nutrient absorption via a cystathionine-β-synthase-derived H2S pathway in rodent jejunum

Ailin Xiao,Jing Li,Tianjian Liu,Zhuxi Liu,Chuanfei Wei,Xiaomeng Xu,Qin Li,Jingxin Li

Summary Hydrogen sulphide (H 2 S) is generated endogenously from l -cysteine ( l -Cys) by the enzymes cystathionine- β -synthase (CBS) and cystathionine- γ -lyase (CSE). In addition, l -Cys is commonly used as a precursor in the food and pharmaceutical industries. The aim of the present study is to determine whether l -Cys regulates intestinal nutrient transport. To that end, the presence of CBS and CSE in the jejunum epithelium was assessed by immunohistochemistry, Western blotting and the methylene blue assay. In addition, in vivo l -Cys (100 mg/kg, administered immediately after the glucose load) significantly increased blood glucose levels 30 min after the oral administration of glucose to mice. This effect of l -Cys was completely blocked by amino-oxyacetic acid (AOA; 50 mg/kg; administered at the same time as l -Cys) an inhibitor of CBS. Measurements of the short-circuit current ( I sc ) in the rat jejunum epithelium revealed that l -Cys (1 mmol/L; 6 min before the administration of l -alanine) enhances Na + -coupled l -alanine or glucose transport, and that this effect is inhibited by AOA (1 mmol/L;10 min before the administration of l -Cys), but not d , l -propargylglycine (PAG;1 mmol/L; 10 min before the administration of l -Cys), a CSE inhibitor. Notably, l -Cys-evoked enhancement of nutrient transport was alleviated by glibenclamide (Gli;0.1 mmol/L; 10 min before the administration of l -Cys), a K + channel blocker. Together, the data indicate that l -Cys enhances jejunal nutrient transport, suggesting a new approach to future treatment of nutrition-related maladies, including a range of serious health consequences linked to undernutrition.

Highly sensitive H2S sensors based on Cu2O/Co3O4 nano/microstructure heteroarrays at and below room temperature

Cui Guangliang,Zhang Pinhua,Chen Li,Wang Xiaoli,Li Jianfu,shi Changmin,Wang Dongchao

Gas sensors with high sensitivity at and below room temperature, especially below freezing temperature, have been expected for practical application. The lower working temperature of gas sensor is better for the manufacturability, security and environmental protection. Herein, we propose a H 2 S gas sensor with high sensitivity at and below room temperature, even as low as −30 °C, based on Cu 2 O/Co 3 O 4 nano/microstructure heteroarrays prepared by 2D electrodeposition technique. This heteroarray was designed to be a multi-barrier system, and which was confirmed by transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and scanning probe microscopy. The sensor demonstrates excellent sensitivity, sub-ppm lever detection, fast response, and high activity at low temperature. The enhanced sensing property of sensor was also discussed with the Cu 2 O/Co 3 O 4 p-p heterojunction barrier modulation and Cu 2 S conductance channel. We realize the detection of the noxious H 2 S gas at ultra-low temperature in a more security and environmental protection way.

Experimental Sensing and Density Functional Theory Study of H2S and SOF2 Adsorption on Au-Modified Graphene

Xiaoxing Zhang,Lei Yu,Xiaoqing Wu,Weihua Hu

A gas sensor is used to detect SF 6 decomposed gases, which are related to insulation faults, to accurately assess the insulated status of electrical equipment. Graphene films (GrF) modified with Au nanoparticles are used as an adsorbent for the detection of H 2 S and SOF 2 , which are two characteristic products of SF 6 decomposed gases. Sensing experiments are conducted at room temperature. Results demonstrate that Au-modified GrF yields opposite responses to the tested gases and is thus considered a promising material for developing H 2 S- and SOF 2 -selective sensors. The first-principles approach is applied to simulate the interaction between the gases and Au-modified GrF systems and to interpret experimental data. The observed opposite resistance responses can be attributed to the charge-transfer differences related to the interfacial interaction between the gases and systems. The density of states and Mulliken population analysis results confirm the apparent charge transfer in Au-modified GrF chemisorption, whereas the van der Waals effect dominates the pristine graphene adsorption systems. Calculation results can also explicate the significant SOF 2 responses on Au-modified GrF. This work is important in graphene modulation and device design for selective detection.

Aqueous-phase dual-functional chiral perovskites for hydrogen sulfide (H2S) detection and antibacterial applications in Escherichia coli

Jingran Zhang,Zihan Yuan,Chao Wang,Lele Liu,Yanan Wang,Yurong Guo,Guangjiu Zhao

Perovskite nanocrystals (PNCs) have attracted extensive attention for their potential applications in biology. However, only a handful of PNCs have been scrutinized in the biological domain due to issues such as instability, poor dispersion, and size inhomogeneity in polar solvents. The development of dual-functional perovskite nanomaterials with hydrogen sulfide (H 2 S) sensing and antibacterial capabilities is particularly intriguing. In this study, we prepared chiral quasi-two-dimensional (quasi-2D) perovskite nanomaterials, Bio(S-PEA) 2 CsPb 2 Br 7 and Bio(R-PEA) 2 CsPb 2 Br 7 , that were uniformly dispersed in aqueous media. The effective encapsulation of methoxypolyethylene glycol amine (mPEG-NH 2 ) improved water stability and uniformity of particle size. Circular dichroism (CD) signals were created by the successful insertion of chiral cations. These perovskites as probes showed a rapid and sensitive fluorescence quenching response to H 2 S, and the effect of imaging detection was observed at the Escherichia coli (E. coli) level. As antibacterial agents, their pronounced positive charge properties facilitated membrane lysis and subsequent E. coli death, indicating a significant antibacterial effect. This work has preliminary explored the application of chiral perovskites in biology and provides insight into the development of bifunctional perovskite nanomaterials for biological applications.

Designed Synthesis of Fe/Zr Bimetallic Organic Framework to Enhance the Selective Conversion of H2S to Sulfur

Xiaoxiao Zheng,Xiaoping Chen,Xiaoqing Li,Jide Zhu,Jipeng Chen,Fengcai Lin,Lijuan Shen,Yanlian Xu,Lilong Jiang

The development of stable and effective catalysts to convert toxic H2S into high value-added sulfur is essential for production safety and environmental protection. However, the inherent defects of traditional iron- and zirconium-based catalysts, such as poor activity, high oxygen consumption, and low sulfur selectivity, limit their further developments and applications. Herein, the Fe–Zr bimetallic organic framework FeUIO-66(x) with different cubic morphologies was synthesized via a facile solvothermal method. The results indicate that the introduction of Fe not only increases the specific surface area and weak L-sites of the catalyst without changing its crystal structure, which provides enough reaction space and more active sites for the adsorption and activation of H2S, but also reduces the activation energy of the reaction, significantly promoting the selective oxidation of H2S. As a result, the as-obtained FeUIO-66(1) catalyst exhibits the highest desulfurization activity and superior durability and water resistance stability, and its H2S conversion and sulfur selectivity within 50 h are 100 and 88%, respectively. More importantly, the structure of the catalyst after the desulfurization reaction is consistent with that of the fresh counterpart. The study offers new insights into the development of effective and stable bimetallic catalysts to eliminate H2S and recycle sulfur.

Effects of hydrogen sulfide (H2S) on respiration control of state 3/4 in mitochondria from bovine heart

Y Su,Y Cheng,D Wang,F Zhang,Y Su,Z Li

Novel NiO nanoflakes in situ grown on graphene layers for the sensitive detection of low concentration H2S

Ming Yang,Lihong Liu,Bo Li,Yannan Mu,Jiaming Chen,Shan Gao,Yingming Xu,Lihua Huo

At present, the effective detection of H 2 S is of indispensable significance for safeguarding human health and maintaining production safety. In this study, a simple ammonia volatile liquid phase deposition method was adopted to in-situ construct cross-linked porous NiO nanoflakes composites on the surface of graphene (Gr) layers under mild conditions from room temperature to calcination. Through regulating the deposition reaction time, the proportion of NiO to Gr components in the composite material can be flexibly controlled. Among them, the NiO nanoflakes/Gr-8 material prepared by deposition for 8 h shows the optimal H 2 S gas sensitivity performance. At the optimal operating temperature of 92℃, the detection limit of H 2 S of this sensor is as low as 10 ppb, and its performance is significantly better than that of most sensing materials. Its outstanding performance stems from multi-dimensional structural optimization: NiO serves as the gas-sensitive active center to dominate the sensing response. The introduction of Gr increases the specific surface area of the material and significantly enhances its electrical conductivity. Particularly crucial is that the p-p heterostructure formed at the NiO/Gr interface effectively promotes the ionization of adsorbed oxygen ions. This study provides a new idea for the development of high-performance H 2 S gas sensors through a collaborative optimization strategy of “active components-conductive substrates-heterostructure interfaces”.

Flower-like In-TiO2@Bi2MoO6 S-scheme heterojunction for efficient visible-light-driven photocatalytic desulfurization of H2S

Yanxu Wang,Jiao Shen,Lijia Huang,Yi Yuan,Yaoqi Huang,Ge He,Yuan Wang,Shaojun Yuan

S-scheme heterojunction photocatalysts have emerged as a promising strategy to overcome the limitations of conventional systems by enabling efficient charge transfer while preserving strong redox capability. In this study, a novel flower-like In-TiO 2 @Bi 2 MoO 6 S-scheme heterojunction was developed via a simple hydrothermal synthesis for visible-light-driven photocatalytic desulfurization of H 2 S. The optimized In-TiO 2 -0.4@Bi 2 MoO 6 composition (molar ratio of In-TiO 2 to Bi 2 MoO 6  = 0.4) achieved complete H 2 S removal within 120 min under visible-light irradiation, exhibiting outstanding activity, operational stability, and adaptability to various desulfurization conditions. Mechanistic investigations using VB-XPS, UPS, ESR, DRIFTS and DFT calculations confirmed that the S-scheme configuration accelerated photoinduced charge separation, reduced electron migration distances, and maintained a high redox potential, thereby promoting efficient generation of reactive oxygen species for sulfur conversion. The synergistic interaction between In-TiO 2 and Bi 2 MoO 6 provides a robust platform for efficient, selective, and durable desulfurization under mild conditions. These findings offer a mechanistic framework for designing next-generation S-scheme photocatalysts for environmental remediation and energy-related applications.