Interfacial built-in electric field and crosslinking pathways enabling WS_(2)/Ti_(3)C_(2)T_(x) heterojunction with robust sodium storage at low temperature

Developing efficient energy storage for sodium-ion batteries(SIBs)by creating high-performance heterojunctions and understanding their interfacial interaction at the atomic/molecular level holds promise but is also challenging.Besides,sluggish reaction kinetics at low temperatures restrict the operation of SIBs in cold climates.Herein,cross-linking nanoarchitectonics of WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,featuring built-in electric field(BIEF),have been developed,employing as a model to reveal the positive effect of heterojunction design and BIEF for modifying the reaction kinetics and electrochemical activity.Particularly,the theoretical analysis manifests the discrepancy in work functions leads to the electronic flow from the electron-rich Ti_(3)C_(2)T_(x) to layered WS_(2),spontaneously forming the BIEF and“ion reservoir”at the heterogeneous interface.Besides,the generation of cross-linking pathways further promotes the transportation of electrons/ions,which guarantees rapid diffusion kinetics and excellent structure coupling.Consequently,superior sodium storage performance is obtained for the WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,with only 0.2%decay per cycle at 5.0 A g^(-1)(25℃)up to 1000 cycles and a high capacity of 293.5 mA h g^(-1)(0.1A g^(-1)after 100 cycles)even at-20℃.Importantly,the spontaneously formed BIEF,accompanied by“ion reservoir”,in heterojunction provides deep understandings of the correlation between structure fabricated and performance obtained.

Synthesis of Mesoporous Chromium Aluminophosphate (CrAlPO) via Solid State Reaction at Low Temperature

Mesoporous chromium aluminophosphate （CrAIPO） was successfully synthesized via solid state reaction （SSR） route at low temperature in the presence of a cationic surfactant cetyltrimethyl ammonium bromide （CTAB） and inorganic sources such as A1C13 · 6H20, CrCI3 · 6H20 and NaH2PO4 · 2H20. Characterizations by means of powder X-ray diffraction （XRD）, N2 adsorption- desorption, high resolution transmission electron microscopy （HR-TEM）, scanning electron micrography （SEM）, energy dispersion spectroscopy （EDS）, thermo-gravimetry （TG）, Fourier transform infrared spectroscopy （FT-IR）, and ultraviolet visible light spectroscopy （UV-Vis） were carried out to understand both the pore characteristics and electron transition route of these obtained materials. The experimental results show that the meso-CrA1PO materials with various Cr/A1 molar ratios possess a mesostructure and a specific surface area of 193 to 310 m2/g corresponding to an average pore size of 5.5 to 2.2 rim, respectively. The maxium content of Cr in meso-CrA1PO materials synthesized via SSR route can achieve 16.7wt%, being significantly higher than that of the meso-CrA1PO prepared via a conventional sol-gel route. Meanwhile, the formation mechanism of the meso-CrA1PO was also proposed.

Doping effect of cations(Zr^(4+),Al^(3+),and Si^(4+)) on MnO_x/CeO_2 nano-rod catalyst for NH_3-SCR reaction at low temperature

Thermally stable Zr4+, Al3+, and Si4+ cations were incorporated into the lattice of CeO2 nano‐rods (i.e., CeO2‐NR) in order to improve the specific surface area. The undoped and Zr4+, Al3+, and Si4+ doped nano‐rods were used as supports to prepare MnOx/CeO2‐NR, MnOx/CZ‐NR, MnOx/CA‐NR, and MnOx/CS‐NR catalysts, respectively. The prepared supports and catalysts were comprehensively characterized by transmission electron microscopy (TEM), high‐resolution TEM, X‐ray diffraction, Raman and N2‐physisorption analyses, hydrogen temperature‐programmed reduction, ammonia temperature‐programmed desorption, in situ diffuse reflectance infrared Fourier‐transform spectroscopic analysis of the NH3 adsorption, and X‐ray photoelectron spectroscopy. Moreover, the catalytic performance and H2O+SO2 tolerance of these samples were evaluated through NH3‐selective catalytic reduction (NH3‐SCR) in the absence or presence of H2O and SO2. The obtained results show that the MnOx/CS‐NR catalyst exhibits the highest NOx conversion and the lowest N2O concentration, which result from the largest number of oxygen vacancies and acid sites, the highest Mn4+ content, and the lowest redox ability. The MnOx/CS‐NR catalyst also presents excellent resistance to H2O and SO2. All of these phenomena suggest that Si4+ is the optimal dopant for the MnOx/CeO2‐NR catalyst.

Preparation of transparent yttrium aluminum garnet ceramics by relatively low temperature solid-state reaction

A new preparation method for a highly sinterable Y 2O 3 powder was developed, using the mixture of the powder with Al 2O 3 powder, a transparent yttrium aluminum garnet(YAG) ceramic was prepared at relatively low temperature by a solid state reaction method. Yttrium nitrate was used as a mother salt, and aqueous ammonia was used as a precipitant reagent, the fine and dendritic precursor crystalline was prepared by adding 0.5% ammonium sulfate into the precipitation reaction system. The highly pure and low agglomerated Y 2O 3 powders were obtained by calcinating the precursor at 1 100 ℃, the primary particles are spherical and 60 nm in diameter. The mixture of Y 2O 3 and Al 2O 3 powders was calcinated, and the resulting mixture compact pressed in mold could be sintered to transparency under vacuum at 1 700 ℃. The sintered transparent YAG polycrystalline exhibits a homogeneous microstructure and its transmittance reaches 45% in the visible light region and 70% in the near infrared wavelength region.

Carbonation Reaction of Lithium Hydroxide during Low Temperature Thermal Energy Storage Process

In order to apply lithium hydroxide(LiOH)as a low temperature chemical heat storage material,the carbonation reaction of LiOH and the prevention method are focused in this research.The carbonation of raw LiOH at storage and hydration condition is experimentally investigated.The results show that the carbonation reaction of LiOH with carbon dioxide(CO_(2))is confirmed during the hydration reaction.The carbonation of LiOH can be easily carried out with CO_(2) at room temperature and humidity.LiOH can be carbonated at a humidity range of 10%to 20%,a normal humidity region that air can easily be reached.Furthermore,the carbonation reaction rate has not nearly affected by the increase of reaction temperature.An improved storage method by storing LiOH at a low humidity less than 1.0%can be effectively prevented the carbonation of LiOH.The hydration reaction ratio of LiOH at the improved storage method shows a better result compared to the ordinary storage method.Therefore,the humidity should be carefully controlled during the storage of LiOH before hydration and dehydration reaction when apply LiOH as a low heat chemical storage material.

Mechanism explanation for SO_2 oxidation rate of Cs-Rb-V series sulfuric acid catalyst at low temperature

The reaction kinetics of SO 2 oxidation on Cs Rb V series sulfuric acid catalyst promoted by alkali salts such as cesium and rubidium was studied. A three step reaction mechanism of SO 2 oxidation was proposed, in which it was assumed that oxidation of quadrivalent vanadium complex was a controlling step. Then, a mechanism model equation was concluded according to the three step reaction mechanism. The SO 2 oxidation rate was measured with a non gradient reactor under the conditions of temperature of 380～520?℃ and space velocity of 3?600～7?200?h -1 . Through calculating with Powell nonlinear regression method, the parameters of model equation were obtained: K 1=0.152?exp(-62?073/ (RT) ), K 2=8.18?exp(-2?384/ (RT) ), K 3=0.221?exp(-18?949/ (RT) ). It was found that the model equation could fit with all the experimental reaction rate data very well. [

Salt-assisted Low Temperature Solid State Synthesis of High Surface Area CoFe_2O_4 Nanoparticles

A novel salt-assisted low temperature solid state method using CoCl2.6H2O, FeCl3.6H2O and NaOH as precursor and using NaCI as a dispersant to synthesize high surface area CoFe2O4 nanoparticles, has been investigated. The effects of the molar ratio of added salt and calcination temperature on the characteristics of the products were investigated by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, vibrating sample magnetometer （VSM） and Brunauer, Emmett and Teller （BET） surface area analysis. Results showed that the introduction of leachable inert inorganic salt as a hard agglomeration inhibitor in the mixture precursor led to the formation of high dispersive CoFe2O4 nanoparticles; and the increase in specific surface area from 28.28 to 73.97 m^2/g, and the saturation magnetization is 84.6 emu/g.

Doping effect of rare earth metal ions Sm^(3+),Nd^(3+)and Ce^(4+)on denitration performance of MnO_(x) catalyst in low temperature NH_(3)-SCR reaction

The MnXO_(x) catalysts(i.e.,MnSmO_(x),MnNdO_(x),MnCeO_(x)) were prepared by reverse co-precipitation method and used for NH_(3)-SCR reaction.It is found that MnCeO_(x) catalyst presents the best low tempe rature catalytic activity(higher than 90% NO_(x) conversion in the te mperature range from 125 to 225℃)and excellent H_(2)O+SO_(2) resistance.In order to explore the reason for this result,the characterization of X-ray diffraction(XRD),Raman spectroscopy,Brunauer-Emmett-Teller(BET),H_(2)-temperature programmed reduction(H_(2)-TPR),NH_(3)-temperature programmed desorption(NH_(3)-TPD),X-ray photoelectron spectroscopy(XPS) and in situ diffuse reflaxions infrared Fourier transformations spectroscopy(DRIFTS) were conducted.The obtained results suggest that MnCeO_(x) catalyst shows the largest amount of acid sites and the best reducibility among these MnXO_(x) catalysts.Besides,Ce^(4+) doping inhibits the crystallization of MnO_(x) catalyst and shows the largest specific surface area.Finally,in situ DRIFTS experiments reveal that NH_(3)-SCR reaction over MnCeO_(x) catalyst follows both Langmuir-Hinshelwood(LH) and Eley-Rideal(E-R) mechanisms,which is through "fast SCR" reaction.

Realizing Complete Solid-Solution Reaction to Achieve Temperature Independent LiFePO_(4) for High Rate and Low Temperature Li-Ion Batteries

The lithium iron phosphate battery(LiFePO4 or LFP)does not satisfactorily deliver the necessary high rates and low temperatures due to its low Li+diffusivity,which greatly limits its applications.The solid-solution reaction,compared with the traditional two-phase transition,needs less energy,and the lithium ion diffusivity is also higher,which makes breaking the barrier of LFP possible.However,the solid-solution reaction in LFP can only occur at high rates due to the lattice stress caused by the bulk elastic modulus.Herein,pomegranate-like LFP@C nanoclusters with ultrafine LFP@C subunits(8 nm)(PNCsLFP)were synthesized.Using in situ X-ray diffraction,we confirmed that PNCsLFP can achieve complete solid-solution reaction at the relatively low rate of 0.1C which breaks the limitation of low lithium ion diffusivity of the traditional LFP and frees the lithium ion diffusivity from temperature constraints,leading to almost the same lithium ion diffusivities at room temperature,0,−20,and−40℃.The complete solid-solution reaction at all rates breaks the shackles of limited lithium ion diffusivity on LFP and offers a promising solution for next-generation lithium ion batteries with high rate and low temperature applications.

Cryoactivated proton-involved redox reactions enable stable-cycling fiber cooper metal batteries operating at-50℃

Fiber-shaped batteries that feature outstanding flexibility,light weight,and wovenability are extremely attractive for powering smart wearable electronic textiles,which further stimulates their demand in extreme environments.However,there are rare reports on ultralow-temperature fiber batteries to date.This is mainly attributed to the poor conductivity of electrodes and freezing of electrolytes that restrain their satisfactory flexible operation in cold environments.Herein,we propose a fiber cooper metal battery consisting of a conductive polyaniline cathode,an anti-freezing Cu(BF4)2+H3PO4electrolyte and an acidresistant copper wire anode,which can withstand various deformations at ultralow temperatures.Impressively,enhanced capacity and cyclic stability can be achieved by cryoactivated abundant reactive sites in the polyaniline,while benefiting from redox reactions with rapid kinetics involving protons rather than copper ions.Consequently,this well-designed polyaniline/Cu fiber battery delivers excellent flexibility without obvious capacity decay after being bent at-30℃,as well as a remarkable discharge capacity of 120.1 mA h g-1and a capacity retention of 96.8%after 2000 cycles at-50℃.The fiber batteries integrated into wearable textiles can power various electronic devices.These performances greatly outperform those of most reported works.Overall,this work provides a promising strategy toward applications of cryogenic wearable energy storage devices.

不同麻醉深度指数下拔管在扁桃体低温等离子射频消融术患儿中的应用效果比较

目的:比较不同麻醉深度指数(NT值)下拔管在扁桃体低温等离子射频消融术患儿中的应用效果。方法:选取2021年7月至2022年4月于该院行扁桃体低温等离子射频消融术的76例患儿进行前瞻性研究,按照随机数字表法将其分为对照组和观察组各38例。两组均行气管插管全身麻醉,对照组于NT值为95~100时拔管,观察组于NT值为80~94时拔管。比较两组不同时间[停止麻醉维持即刻(T_(0))、拔管后即刻(T_(1))、拔管后10 min(T_(2))]血流动力学指标(心率、平均动脉压、呼吸频率)水平、不同时间(拔管前、拔管后30 min)应激指标[皮质醇(Cor)、肾上腺素(E)]水平、不同时间(T_(0)、T_(1)、T_(2))局部脑氧饱和度(rSO_(2))水平和不良反应发生率。结果:T_(1)、T_(2)时,两组平均动脉压、心率、呼吸频率均高于T_(0)时,但观察组低于对照组,差异有统计学意义(P<0.05);拔管后30 min,两组Cor、E水平均高于拔管前,但观察组低于对照组,差异有统计学意义(P<0.05);T_(0)、T_(1)、T_(2)时,两组rSO_(2)水平比较,差异均无统计学意义(P>0.05);观察组不良反应发生率为5.26%(2/38),低于对照组的21.05%(8/38),差异有统计学意义(P<0.05)。结论:NT值为80~94时拔管应用于扁桃体低温等离子射频消融术患儿可改善血流动力学指标和应激指标水平,降低不良反应发生率,效果优于NT值为80~94时拔管。

CO优先氧化反应MnCu/Ce催化剂的制备及性能

采用共浸渍法制备较低Cu含量的MnCu/Ce催化剂,通过XRD、BET、H_(2)-TPR、XPS和CO_(2)-TPD等表征手段对催化剂进行表征,考察催化剂焙烧温度对催化剂结构、性质及其在含有CO_(2)的富氢气氛下对CO优先氧化性能的影响。结果表明,MnCu/Ce催化剂均有Cu/Mn-O-Ce固溶体形成,其中,在焙烧温度600℃制备的催化剂中,Mn与Cu、Ce之间相互作用较强,形成较多三元氧化物固溶体,氧空位/Ce^(3+)含量高,具备良好的CO-Prox活性。此外,对反应条件的考察发现,添加不同分压Ar对催化剂的CO-Prox活性影响较小,气体空速和氧过量系数对催化剂活性影响较大,且反应原料气中CO_(2)的存在对CO-Prox反应有负面影响。氧过量系数为1.2、空速范围为20266-30400 mL/(g·h)时,CO转化率最高,达到94.7%。

塔中深层稠油减氧空气驱氧化特征及机理研究

针对塔中深层稠油油藏开展静态氧化实验,通过测试分析不同氧含量与不同氧化时间下产出油气组成,研究了油藏注减氧空气过程中原油与减氧空气的氧化特征、氧化途径与氧化机理。实验结果表明,原油的耗氧速率与减氧空气的氧含量呈正相关,与氧化时间呈负相关;二氧化碳的生成量随氧化时间与减氧空气氧含量的增加而增大;原油与减氧空气的反应会一定程度上使原油黏度增加,其黏度增加的幅度随减氧空气氧含量的升高和氧化时间的增长而增大;氧化后原油饱和烃与芳香烃的含量减少,胶质与沥青质的含量增加,且沥青质增加更为明显。原油在氧化后出现了C=O的伸缩振动峰,且振动峰随着减氧空气氧含量的增加而增强,说明原油在氧化过程中发生了加氧反应生成了醛类等物质,且氧化反应随着氧含量的升高而不断加深。

碳布负载的钴镍双金属沸石咪唑框架作为独立电极用于高效电催化析氧反应

开发低成本、高效和稳定的电催化剂对于加快水分解中的析氧反应(OER)速率,实现可再生、清洁和大规模能源转换技术至关重要。在本文中,我们开发了一种简单的方法来制备钴镍双金属沸石咪唑框架(CoNi-ZIF),通过低温热解去除客体分子将CoNi-ZIF纳米片牢固地负载到碳布(CoNi-ZIF-CC-200)上。组装的独立电极避免了对粘合剂的依赖和无效表面积的增加,从而显著提高了催化剂的催化活性和传质效率。电化学测试结果表明CoNi-ZIF-CC-200独立电极在OER过程中表现出良好的电化学活性和稳定性。CoNi-ZIF-CC-200独立电极在10 mA·cm^(-2)下表现出255 mV的低过电位,并且在恒电位测量过程中保持10 h以上的稳定运行。此外,由CoNi-ZIF-CC-200独立电极作为阳极和Pt/C作为阴极组成的水分解系统表现出优异的稳定性。

调控五配位Al^(3+)含量制备高性能低温Sabatier反应催化剂

为了制备出高性能低温Sabatier反应Ru基催化剂,通过调控Al_(2)O_(3)载体中五配位Al^(3+)的含量(五配位Al^(3+)占Al物种的比例),实现对Ru基活性位点电子性质的调控。在此过程中,利用~(27)Al固体核磁共振(~(27)Al-NMR)检测Al_(2)O_(3)载体中五配位Al^(3+)的含量,借助X射线光电子能谱仪(XPS)和H_2程序升温还原(H_(2)-TPR)考察Ru基活性位点电子性质的调控效果,利用固定床反应器测试催化剂性能。结果表明,Al_(2)O_(3)载体中的五配位Al^(3+)可有效调控Ru基活性位点的电子性质,进而提升低温Sabatier反应Ru基催化剂性能。其中,以五配位Al^(3+)含量约为28.1%的Al_(2)O_(3)载体制备的Ru基催化剂,在低温区(<300℃)的CO_(2)转化率和CH_4选择性均可达90%以上。而且,在100 h的稳定性测试中,催化性能没有明显降低。

基于自燃烧技术的铁铝酸钙固溶体低温制备与特性研究

熟料煅烧是影响硅酸盐水泥生产能耗的关键环节,而熟料矿物相的高效能低温制备是水泥工业研究的重点。以可溶性的金属硝酸盐和尿素为原料,借助自蔓延燃烧(SPCR)法在低温下制备出铁铝酸四钙(C_(4)AF),并借助X射线衍射(XRD)、傅里叶变换红外(FTIR)、扫描电子显微镜(SEM)和等温微量热技术,研究了合成C_(4)AF的矿物组成、结晶程度、颗粒形貌、水化特性等特性。结果表明:SPCR法能够在500℃恒温2 h制备出纯度和结晶程度均较好的C_(4)AF,优选的原材料质量比为mCa(NO_(3))_(2)·4H_(2)O∶mAl(NO_(3))_(3)·9H_(2)O∶mFe(NO_(3))_(3)·9H_(2)O∶mCO(NH_(2))_(2)=1.259∶1.0∶1.077∶2.664。CaCO_(3)是SPCR法制备C_(4)AF的过渡相,增加尿素用量有利于提高反应温度,改善C_(4)AF的结晶程度。合成C_(4)AF具有较高的水化活性,水化30 min内出现放热峰,水化过程中无休眠期出现,完全水化时的水化热为474 J/g。

低温等离子体协同催化CH_(4)-CO_(2)重整反应的研究进展

低温等离子技术的出现为甲烷、二氧化碳重整反应提供了新的思路。阐述了低温等离子体协同催化CH_(4)-CO_(2)重整,并且生成高附加值化学品的合成气(CO和H 2)的基本原理,探究了低温等离子体协同催化CH_(4)-CO_(2)重整反应的反应机理,分析了低温等离子体在协同催化CH_(4)-CO_(2)重整反应中的作用机制,讨论了催化剂的活性组分、载体以及助剂对重整反应的影响,并综述了当前低温等离子协同催化CH_(4)-CO_(2)重整反应过程中的影响因素及存在的问题。

马来酸酐改性高掺量橡胶沥青制备与性能

使用高度降解的再生橡胶(DR)制备了高掺量橡胶沥青(HCRA),通过衰减全反射傅里叶变换红外光谱仪、凝胶渗透色谱仪、动态剪切流变仪和动态力学分析仪,对比研究了马来酸酐(MAH)预接枝DR改性与MAH和DR直接共混改性对HCRA结构与性能的影响,探讨了两种改性方法的改性机理。结果表明,MAH预接枝DR时发生了由烯烃双键和烯丙基碳氢原子提供活性位点的自由基取代反应,而MAH和DR与沥青直接共混时,存在自由基取代反应和酯化反应两种反应,并以后者为主;MAH改性HCRA的溶胶组分中以中低分子量组分为主;MAH改性显著改善了HCRA的高、低温流变性能。此外,两种改性方法对HCRA的结构与性能均有影响,且随MAH掺量的变化存在明显差异。

三维花状铜基复合物及其低温煅烧衍生物用于高效析氧反应

采用一种简单易行的方法来制备铜基电化学催化剂,该催化剂用于析氧反应。利用沸石咪唑酯骨架-67(ZIF-67)为前驱体,通过铜离子刻蚀合成新型铜基复合物(命名为Cu-NF)。它具有特殊的三维花状形貌和中孔结构,其形貌受铜离子与ZIF-67的质量比的影响。随后,Cu-NF经过低温煅烧处理,得到了不同温度下的衍生物,而煅烧过程并未改变其原始形貌。煅烧温度决定了活性物种的组成及含量,并增强了材料的多孔性。其中,300℃煅烧得到的产物Cu-NF-300具有最好的析氧反应性能:在1.0 mol·L^(-1)KOH溶液中,过电位低达347 mV,塔菲尔斜率为93 mV·dec^(-1)。该材料电化学性能的提高归因于其三维结构以及低温煅烧所带来的活化作用。

Simultaneous removal of sulfur dioxide and nitrogen oxide from flue gas by phosphorus sludge:The performance and absorption mechanism

Developing low-cost and green simultaneous desulfurization and denitrification technologies is of great significance for sulfur dioxide(SO_(2))and nitrogen oxide(NO_(x))emission control at low temperatures,especially for small and medium-sized coal-fired boilers and furnaces.Herein,phosphorus sludge,an industrial waste from the production process of yellow phosphorus,has been developed to simultaneously eliminate SO_(2)and NO_(x)from coal-fired flue gas.The key factors affecting the experimental results indicate that desulfurization and denitrification efficiency of over 95%can be achieved at a low temperature of 55℃.Further,the absorption mechanism was investigated by characterizing the solid and liquid phases of the phosphorus sludge during the absorption process.The efficient removal of SO_(2)is attributed to the abundance of iron(Fe^(3+))and manganese(Mn^(2+))in the absorbent.SO_(2)can be rapidly catalyzed and converted to SO_(4)^(2-)by them.The key to NOx removal is the oxidation of NO toward watersoluble high-valent nitrogen oxides by oxidizing reactive substances induced via yellow phosphorus,which are then absorbed by water and converted to NO_(3)^(-).Meanwhile,yellow phosphorus is oxidized to phosphoric acid(H_(3)PO_(4)).The spent absorption slurry can be reused through wet process phosphoric acid production,as it contains sulfuric acid(H_(2)SO_(4)),nitric acid(HNO_(3)),and H_(3)PO_(4).Accordingly,this is a technology with broad application prospects.