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1.
Among challenges implicit in the transition to the post±fossil fuel energetic model, the finite amount of resources available for the technological implementation of CO2 revalorizing processes arises as a central issue. The development of fully renewable catalytic systems with easier metal recovery strategies would promote the viability and sustainability of synthetic natural gas production circular routes. Taking Ni and NiFe catalysts supported over γ-Al2O3 oxid...  相似文献   

2.
The natural gas(NG) reforming is currently one of the low-cost methods for hydrogen production. However, the mixture of H2 and CO2 in the produced gas inevitably includes CO2 and necessitates the costly CO2 separation. In this work, a novel double chemical looping involving both combustion(CLC) and sorption-enhanced reforming(SE-CLR) was proposed towards the co-production of H2 and CO(CLC-SECLRHC) in two separated streams. CLC provides react...  相似文献   

3.
The activation of H2O is a key step of the COS hydrolysis,which may be tuned by oxygen vacancy defects in the catalysts.Herein,we have introduced Cu into Co3O4 to regulate the oxygen vacancy defect content of the catalysts.In situ DRIFTS and XPS spectra reveal that COS and H2O are adsorbed and activated by oxygen vacancy.The 10 at% Cu doped Co3O4 sample(10Cu-Co3O4) exhibits the optimal activity,100% of COS co...  相似文献   

4.
Despite wide applications of noble metal-based catalysts in 5-hydroxymethylfurfural(HMF) oxidation,promoting the catalytic performance at low loading amounts still remains a significant challenge.Herein,a series of metal oxide modified MOx-Au/TiO2(M=Fe,Co,Ni) catalysts with low Au loading amount of 0.5 wt% were synthesized.Addition of transition metal oxides promotes electron transfer and generation of the Auδ--Ov-Ti3+ interface.A combinatio...  相似文献   

5.
Catalytic oxidation of benzene with N2O to phenol over the hierarchical and microporous Fe/ZSM-5-based catalysts in a continuous fixedbed reactor was investigated.The spent catalyst was in-situ regenerated by an oxidative treatment using N2O and in total 10 reaction-regeneration cycles were performed.A 100% N2O conversion,93.3% phenol selectivity,and high initial phenol formation rate of 16.49±0.06mmolphenol gcatalyst-1 h-1  相似文献   

6.
Adsorptive removal of heavy metal ions from wastewater is very important, and the key is the development of efficient sorbents. In this work,oxygenated alkynyl carbon materials(OACMs) were synthesized via mechanochemical reaction of CaC2 and a carbonate(CaCO3, Na2CO3, or NaHCO3) at ambient temperature. The resultant OACMs are micro mesoporous carbon nanomaterials with high specific area(>648 m2g-1),highly crosslinked...  相似文献   

7.
High activity and productivity of MoVNbTeOx catalyst are challenging tasks in oxidative dehydrogenation of ethane(ODHE) for industrial application.In this work,phase-pure M1 with 30 wt% CeO2 composite catalyst was treated by oxygen plasma to further enhance catalyst performance.The results show that the oxygen vacancies generated by the solid-state redox reaction between Ml and CeO2 capture active oxygen species in gas and transform V4+ to V5+  相似文献   

8.
Porous ZIF-7 with the sodalite (SOD) cage structure (ZIF, Zeolitic imidazolate framework) were synthesized by the solvothermal method. Synthesized material was characterized by powder X-ray diffraction (PXRD), thermal gravity (TG), scanning electron micro- scopy (SEM) and Na adsorption analysis. ZIF-8 with the SOD structure and a littl larger pore window was synthesized in a similar way and was characterized for comparisons. Thermal stability and structural stability of ZIF-7 were tested through PXRD analysis, and the capability of the material for CO2 capture from simulated flue gas was investigated through physical adsorption method. The results showed that CO: adsorption capacity on ZIF-7 was about 48 mL. gl while the capacity on ZIF-8 was about 18mg.g-1 (at 12C and 0.98 P/Po relative pressure). Furthermore, the impact of flue gas components on adsorption capacity of ZIF-7 and the selectivity of CO2 against N2 on ZIF-7 was also investigated in this work  相似文献   

9.
本工作采用机械混合方法,将TiO2纳米颗粒与不同质量的g-C3N4复合,制备了一系列具有不同g-C3N4含量的TiO2/g-C3N4复合材料.运用X射线粉末衍射(XRD)、X射线光电子能谱(XPS)、拉曼光谱(Raman)、比表面积分析仪(BET)、扫描电镜(SEM)和透射电镜(TEM)对材料的化学组成和形貌特征进行了表征.比较了g-C3N4、TiO2和一系列TiO2/g-C3N4在可见光驱动下对水中双酚A(BPA)的降解效率和矿化能力差异,发现TiO2/g-C3N4的光催化活性显著高于g-C3N4和TiO2,其中以TiO2/g-C...  相似文献   

10.
以MoS2为载体,通过水热法合成Fe3O4/MoS2催化剂,采用X射线衍射、透射电子显微镜和X射线光电子能谱分析对材料进行表征,研究了Fe3O4/MoS2/PMS体系中2,4-二氯苯氧基乙酸(2,4-D)的降解效率并探究了其反应机理.结果表明,以Fe3O4、MoS2和Fe3O4/MoS2为催化剂,30 min内2,4-D的去除率分别为31%、 20%和89%.表征结果发现,在MoS2的存在下,Fe3O4表面的Fe(Ⅲ)还原为Fe(Ⅱ),Mo(Ⅳ)被氧化为Mo(Ⅵ),Fe3O4和MoS2间的协同作用加强了PMS分解,提高了2,4-D去除效率.自由基淬灭实验表明,·OH、 SO<...  相似文献   

11.
开发具有低温、高活性、高抗硫抗水性的NH3-SCR脱硝催化剂成为目前广大学者的主要研究方向。锰铈催化剂因为其优异的低温活性而具有广阔的应用前景,但反应气氛中的SO2和H2O会使催化剂中毒。本文分析了以TiO2为载体的锰铈基催化剂在低温氨选择性催化还原过程中SO2和H2O的中毒机理,重点从添加助剂和改变催化剂形貌两方面介绍了提高锰铈催化剂抗硫抗水性的研究进展。最后针对目前锰铈催化剂存在的问题对其研究方向进行了展望。  相似文献   

12.
由于工业化进程的不断推进,染料与重金属废水被非法排入自然水体,水体污染问题日益严峻.为实现两种污染物的同时去除,本文通过调控合成MoS2/WSe2(MW)异质结复合催化材料,提高其催化活性.黑暗条件下,以MoS2、WSe2以及MW为阳极材料,g-C3N4为阴极材料组建自偏压燃料电池系统,实现在降解有机染料的同时,去除水体中的重金属离子.通过调控参数,探究影响染料与重金属去除的因素.研究表明,影响重金属和有机染料去除效果的因素有pH、电解质溶液浓度、重金属溶液浓度.当溶液pH=5,电解质溶液浓度为0.1 mol·L-1,铜离子浓度为4 mg·L-1时,重金属的去除率为64.3%.当溶液pH=5,电解质溶液浓度为0.2 mol·L-1,铜离子浓度为2 mg·L-1时,有机染料罗丹明B的去除率为99.5%.该系统在无外加光照条件下,实现不同类型污染物同时去除,并产生约240 ...  相似文献   

13.
王婷婷  任刚  关健聪  余燕 《环境化学》2023,(7):2403-2410
本文以盐酸林可霉素(LCM)为研究对象,探究其在UV/H2O2降解作用下的降解情况,探讨了H2O2浓度、初始pH值和有机物等影响因素对LCM的影响及机制.实验结果表明,当H2O2浓度为50 mg·L-1,pH=7.3,LCM浓度为10 mg·L-1,反应30 min后,LCM去除率达到98%,且反应过程遵循准一级动力学.利用高效液相色谱串联飞行时间质谱仪(LCMS-TOF 5600+)鉴别出其在UV/H2O2降解过程中主要产物的分子结构式,进而推导出可能的降解路径.利用TEST对降解过程中的产物进行毒性预测,结果表明,中间产物的毒性高于母体,对水质安全保障造成潜在风险.  相似文献   

14.
The artificial nitrogen(N2) reduction reaction(NRR) via electrocatalysis is a newly developed methodology to produce ammonia(NH3) at ambient conditions,but faces the challenges in N2 activation and poor reaction selectivity.Herein,Nb-based MXenes are developed to remarkably enhance the NRR activity through the engineering of the stretched 3D structure and oxygen vacancies(VO).The theoretical studies indicate that N2 could be initially adsorb...  相似文献   

15.
Disulfide zirconium(ZrS2) is a two-dimensional(2D) transition metal disulfide and has given rise to extensive attention because of its distinctive electronic structure and properties.However,mass production of high quality of ZrS2 nanosheets to realize their practical application remains a challenge.Here,we have successfully exfoliated the bulk ZrS2 powder with the thickness of micron into single and few-layer nanosheets through liquid-phase exfoliation in N-meth...  相似文献   

16.
轮作休耕是实现"藏粮于地、藏粮于技"的重要途径之一,目前在太湖稻田区域主要推广紫云英(Astragalus sinicus L.)-水稻(Oryza sativa L.)、油菜(Brassica napus L.)-水稻和休耕-水稻典型轮作与休耕方式。在太湖地区典型稻田水稻生长季设置了6个处理:(1)紫云英-水稻轮作,不施N肥处理,MRN0;(2)紫云英-水稻轮作,当地常规施肥量(300 kg·hm-2,以纯氮计,下同),MRN300;(3)油菜-水稻轮作,不施N肥处理,RRN0;(4)油菜-水稻轮作,当地常规施肥量(300 kg·hm-2),RRN300;(5)休耕-水稻轮作,不施N肥处理,FRN0;(6)休耕-水稻轮作,当地常规施肥量(300 kg·hm-2),FRN300。通过田间试验,研究了不同轮作与休耕方式对水稻产量、氮肥利用率及稻田温室气体CH4和N2O排放的影响,从而为综合评价轮作休耕方式提供科学依据。田间试验结果显示,与不施氮肥处理相比,在不同轮作休耕方式下施氮300 kg·hm-2,可增加53.7%—60.0%的水稻产量,以MRN300处理水稻产量最高,与RRN300和FRN300处理相比,水稻产量分别提高了1.6%和6.0%。在不施氮水平下,MRN0、RRN0和FRN0各轮作处理间N2O排放通量和累积排放量均值差异不显著(P>0.05)。而在施氮300 kg·hm-2下,紫云英-水稻轮作可降低N2O排放通量和累积排放量,与RRN300和FRN300处理相比,N2O排放通量分别降低了36.0%(P<0.05)和2.1%(P>0.05)。在同一施氮水平下,紫云英-水稻轮作CH4排放通量和累积排放量最小,与RRN300和FRN300处理相比,MRN300处理CH4排放通量分别降低了1.1%和6.7%,CH4和N2O的全球增温潜势(GWP)分别降低了3.3%和6.5%,单位水稻产量温室气体排放强度(GHGI)分别降低了4.6%和11.6%。综上,紫云英-水稻轮作对提高水稻产量,降低温室气体排放效果最好。  相似文献   

17.
Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources,requiring additional CO2 capture to decarbonize, which energy intense and costly. In a recent Green Energy & Environment paper, Cheng and Di et al. proposed a novel integration process referred to as SECLRHC to generate high-purity H2 by in-situ separation of H2 and CO without using any additional separation unit. Th...  相似文献   

18.
TiO2 has demonstrated outstanding performance in electrochemical advanced oxidation processes(EAOPs) due to its structural stability and high oxygen overpotential.However,there is still much room for improving its electrochemical activity.Herein,narrow bandgap manganese oxide(MnOx) was composited with TiO2 nanotube arrays(TiO2 NTAs) that in-situ oxidized on porous Ti sponge,forming the MnOx-TiO2 NTAs anode.XANES and XPS analysis further prov...  相似文献   

19.
研究混合胺溶液吸收二氧化碳(CO2)的反应机理对低碳环保具有重要意义.本文以碳酸钙(CaCO3)为催化剂,在Eley-Rideal模型下通过Gaussian09软件模拟计算乙醇胺(MEA)+CO2反应机理,,同时计算混合胺溶液体系乙醇胺(MEA)+二乙醇胺(DEA)/2-氨基-2-甲基-1-丙醇(AMP)/N-甲基二乙醇胺(MDEA)吸收CO2中经实验证明的协同效应.本文在CCSD(T)/6-311++G(d,p)水平上计算在两性离子机理下中间步骤的自由能和几何振动频率.模拟结果表明,在固体催化剂CaCO3作用下,反应活化能降低了14.9%,但是自由能没有降低.混合胺盐能量(MEA-DEA-CO2,MEA-AMP-CO2)低于MEA-CO2-MEA能量,差距分别为-18.25%和-14.5%,而MEA-MDEA-CO2体系能量与单一溶液体系差距仅为-5.88%.这表明二级胺,空间位阻胺的协同效应大于三级胺.  相似文献   

20.
本研究以硝酸铈、硝酸锆为原料使用溶剂热合成法,制备了CeO2-ZrO2纳米棒催化剂(Ce0.7Zr0.3O2(NR)),并用于柴油车尾气碳颗粒催化净化.催化活性检测证实:Ce0.7Zr0.3O2(NR)纳米棒催化剂可有效净化柴油车尾气碳烟颗粒.在Ce0.7Zr0.3O2(NR)存在下,碳颗粒净化率为10%、50%和90%时,所需温度分别仅为375℃、414℃和455℃,比商用Ce0.7Zr0.3O2和Ce0.3Zr0.7O2催化剂性能更优.采用氮吸附-脱附、X射线光电子能谱(XPS)、H2程序升温还原(H2-TPR)、X射线衍射(XRD)、拉曼光谱(Raman)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等技术对催化剂进行表征.XRD和Raman结果证实,Ce0.7Zr0.3O2(NR)主要由立方相CeO2构成,并掺杂了少量四方相氧化锆.SEM和TEM结果则显示,Ce0.7Zr0.3O2(NR)催化剂颗粒明显由纳米棒堆积而成,特定的纳米形貌会影响其对碳颗粒的催化氧化活性.XPS结果证明Ce0.7Zr0.3O2(NR)催化剂主要具有晶格氧、化学氧和表面吸附氧等氧物种;晶格氧是碳颗粒氧化的活性氧物种,其溢流到催化剂表面可与碳颗粒接触从而提高反应活性;化学氧和表面吸附氧均为表面氧物种,极易与表面固体碳颗粒直接接触,从而可在较低温度下促进碳颗粒的净化.H2-TPR结果进一步证实了XPS结果,Ce0.7Zr0.3O2(NR)催化剂的低温还原温度比商用Ce0.7Zr0.3O2催化剂更低,且含有更多的易还原氧物种,这些低温易还原氧物种可以在较低温度下参与催化反应,促进柴油车尾气颗粒物的低温催化净化.  相似文献   

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