木醋调质石灰石用于O2/CO2燃煤同时脱硫脱硝性能

采用管式炉和沉降炉分别研究了O₂/CO₂气氛下燃煤预混和烟气喷入木醋调质石灰石的同时脱硫脱硝性能。结果表明,在温度1 173~1 323 K、钙硫比为2.0的条件下,木醋调质石灰石混煤燃烧脱硫效率91.0%~94.9%、脱硝效率23.5%~30.8%。随着钙硫比的增加,木醋调质石灰石混煤燃烧脱硫脱硝效率增大,适宜的钙硫比为1.5~2.0。相同的燃烧温度和钙硫比,含硫量高的煤预混木醋调质石灰石燃烧获得较高的脱硫、脱硝效率。木醋调质石灰石用于O₂/CO₂燃煤脱硫脱硝性能优于醋酸钙。O₂/CO₂燃煤烟气中喷入木醋调质石灰石、钙硫比为2.0、停留时间为0.8 s、在1 223和1 323 K时获得最大脱硫效率和最大脱硝效率为75.8%和86.6%。在上述条件下将氨气喷入反应区,氨氮比为0.75、温度为1 223和1 323 K时,脱硫效率分别为73.2%和63.9%,脱硝效率分别为93.2%和94.8%。     

M-Y/AC催化剂同时脱硫脱硝性能研究

采用等体积浸渍法制备了一系列的1%M-6%Y/AC(M为Ni、Al、Mo)催化剂,以CO作为还原剂,考察其同时脱硫脱硝的催化活性,通过X射线衍射(XRD)、H2-程序升温还原(H2-TPR)、比表面积(BET)对催化剂进行表征。活性评价结果表明,1%Ni-6%Y/AC催化剂的脱硫脱硝催化活性最佳,无氧条件下SO_2和NO的t90分别为383和378℃。在考察Ni O的负载量对催化剂影响中,0.5%Ni-6%Y/AC催化活性最佳,无氧条件下SO_2和NO的t90分别为370和360℃。     

基于H2O2的自燃离子液体研究进展

基于H₂O₂的自燃离子液体是目前绿色自燃推进剂领域的一个重要研究方向。本文对H₂O₂—离子液体的自燃体系进行了综述,富B-H类和硫氰酸阴离子类离子液体能与H₂O₂直接自燃,在加入碘铜酸盐等促进剂后达到更好的点火效果;此外二氰胺根阴离子类、二甲基硼磷酸根阴离子类和醋酸根阴离子类等离子液体不能与H₂O₂直接自燃,但加入促进剂后能达到良好点火效果。进一步介绍了各类自燃离子液体的合成方法和理化性质,提出基于H₂O₂—离子液体自燃推进剂的研究重点应着眼于以下三方面：更高能量密度离子液体的设计合成、高活性促进剂的研制开发以及强化点火的内在机制。     

亚氯酸钠溶液同时脱硫脱硝的热力学研究

在自行设计的小型鼓泡反应器中, 以亚氯酸钠溶液作为吸收剂, 进行了模拟烟气同时脱硫脱硝实验研究, 得到反应的最佳实验条件以及在此条件下同时脱硫脱硝效率. 分析了反应产物, 推导出了亚氯酸钠溶液与硫氧化物、氮氧化物的反应历程以及总化学反应方程式. 利用热力学原理计算出亚氯酸钠溶液同时脱硫脱硝的摩尔反应吉布斯函数、摩尔反应焓变、化学反应平衡常数以及化学反应达到平衡时SO2和NO的分压力. 结果表明: 亚氯酸钠溶液同时脱硫脱硝是可行的, 且可以几乎100%的脱除烟气中的SO2和NO.     

CaCl2/H2O2引发木质素接枝天然橡胶的制备及其应用研究

添加增容剂是改善极性木质素(LN)与非极性橡胶相容性差的有效措施之一,有助于提高LN补强效果.本文中采用CaCl₂/H₂O₂作为自由基引发体系制备了LN接枝的天然橡胶(LGN),并将其用于天然橡胶(NR)/LN复合材料的界面增容.研究表明,CaCl₂/H₂O₂不但可以引发LN产生大分子自由基,而且会氧化NR双键断裂生成不饱和酮,使NR分子量降低.对接枝过程中加料顺序进行调控,采用CaCl₂/H₂O₂先处理LN,不但可以有效地减轻NR的氧化降解,而且有助于LN产生更多的大分子自由基.采用傅里叶变换红外光谱(FTIR)对LN、NR和LGN化学结构的表征表明：LN接枝NR的机理为LN的酚羟基自由基与NR的甲基反应形成C―O―C键.得益于LGN优异的界面增容作用,增容后的NR/LN复合材料的拉伸强度和撕裂强度较增容前分别提高了14.3%和7.5%.     

Simultaneous desulfurization and denitrification of flue gas by using urea/H2O2 solution

在填料塔上对尿素/H2O2溶液同时脱硫脱硝进行了实验研究.结果表明,尿素溶液对SO2具有很高的去除效率,但对NOx的去除受到多种因素的影响.实验主要研究了H2O2浓度、吸收反应温度、溶液pH值等因素对脱硝效率的影响,并确定了最佳实验条件,在此条件下脱硫脱硝效率分别达到100％和52.6％.同时,采用化学分析法和气相色谱法对尿素溶液同时脱硫脱硝的反应产物进行分析,推导出尿素/H2O2溶液同时脱硫脱硝的反应机理和总化学反应方程式.该技术可用于对现有湿法脱硫技术的改造,使其同时具有脱硫脱硝功能.     

氨再生条件对V2O5/AC同时脱硫脱硝活性的影响

对烟气同时脱硫脱硝过程中吸附SO2后的活性炭载V2O5（V2O5/AC）催化 吸附剂在含NH3气氛下的再生条件进行了考察,发现3%～5%NH3/Ar气氛、300℃、60min再生可有效恢复V2O5/AC的脱硫活性,并明显提高其脱硝活性。基于对SO2和NO的脱除率、再生后V2O5/AC的硫质量分数以及FT IR谱图分析发现,NH3的存在对V2O5/AC所吸附硫的脱附行为没有明显影响,但可显著改变V2O5/AC的表面化学性质,有利于烟气脱硫;NH3还可在V2O5/AC表面储存,显著促进脱硝。     

S型异质结H2O2光催化剂的研究进展(英文)

随着现代经济和工业的快速发展,传统化石能源的过度开发和消耗造成了日益严重的环境污染和能源危机,极大地威胁着我们的健康和生活。我们需要开发新的可持续技术来解决日益恶化的环境和能源问题。太阳能作为一种绿色、可持续的清洁能源,在过去几十年中受到了广泛的关注。因此,开发和利用太阳能对解决当前面临的问题具有重要意义。半导体光催化技术是一种太阳能驱动的半导体材料表面催化反应过程,可利用太阳能并将其转化为其他能源,用于进一步的能量存储和应用。目前,制备高效稳定的光催化剂仍然是一个巨大的挑战。最近,为了解决传统异质结光催化剂电荷转移过程中的缺点和不足,一种新型梯形(S型)异质结概念被首次提出。S型异质结不仅有效地解决了电荷转移问题,实现了载流子的快速分离,而且保留了光催化体系最强的氧化还原能力,提高其光催化性能。到目前为止,各种S型异质结已被开发并应用于太阳能转化可用化学燃料领域以减少化石燃料的使用。此外,S型异质结也可用于降解污染物,以减少化石燃料的消耗所造成对环境恶化的影响。过氧化氢(H₂O₂)作为一种有效、多用途、绿色的氧化剂,已应用于诸多领域,包括污...     

Ga2O3催化剂上CO2气氛中丙烷脱氢反应的研究

考察了Ga2O3对于丙烷脱氢和CO2气氛脱氢反应的催化性能. 结果表明, Ga2O3具有较高的催化活性, 其性能优于传统的Cr2O3脱氢催化剂. 催化反应可能经过了一个丙烷异裂的过程, 其中CO2是通过逆水煤气反应和Boudouard反应来促进催化剂性能的, 在高于823 K时该促进作用更为明显. 催化剂的催化活性和其表面酸密度密切相关, 在Ga2O3结构中, 四配位Ga3+是其酸位的来源, 并通过质子与氧化物的共同作用促进反应进行. 催化剂的失活是由于表面的积碳和活性氧的消耗共同造成的. 同时还对Ga2O3作为丙烷脱氢反应的催化剂的催化反应机理进行了初步探讨.     

石墨烯-铁卟啉复合材料的制备及其H2O2传感器应用研究

本文通过π-π非共价键的方式合成了具有仿生功能的石墨烯-铁卟啉复合材料,并将其修饰在玻碳电极上,制备成一种新型的无酶H2O2传感器。利用傅里叶变换红外(FT-IR)光谱、紫外-可见吸收光谱(UV-Vis)及电化学阻抗谱(EIS)对合成材料进行了表征,并研究了该传感器对H2O2的电催化还原性能。实验结果表明,该传感器对H2O2具有较好的催化还原效果,能够在-0.24V电位下对H2O2进行测定;其对H2O2的线性检测范围为5.0×10-7～1.975×10-4 mol/L,检测限为4.1×10-7 mol/L。     

Experimental and mechanism studies on simultaneous desulfurization and denitrification from flue gas using a flue gas circulating fluidized bed

The oxidizing highly reactive absorbent was prepared from fly ash,industry lime,and an oxidizing additive M.Experiments of simultaneous desulfurization and denitrification were carried out in a flue gas circulating fluidized bed(CFB).The effects of influencing factors and calcium availability were also investigated on the removal efficiencies of desulfurization and denitrification.Removal efficiencies of 95.5%for SO2 and 64.8%for NO were obtained respectively under the optimal experimental conditions. The component of the spent absorbent was analyzed with chemical analysis methods.The results in- dicated that more nitrogen species appeared in the spent absorbent except sulfur species.A scanning electron microscope(SEM)and an accessory X-ray energy spectrometer were used to observe micro-properties of the samples,including fly ash,oxidizing highly reactive absorbent and spent absorbent.The simultaneous removal mechanism of SO2 and NO based on this absorbent was pro- posed according to the experimental results.     

超临界水热极速合成异质结构H4SiW12O40/Bi2WO6光催化剂及其脱氮性能

采用超临界水热合成方式极速合成一种H_4SiW_(12)O_(40)/Bi_2WO_6光催化剂,通过X射线衍射(XRD)、场发射扫描电子显微镜(SEM)、透射电子显微镜(TEM)、比表面积及孔隙度(BET)测定对所合成催化剂的结构和性质进行了考察,并以吡啶含量为15 mg/g的模拟油对光催化剂的脱氮效果进行评价。结果表明,该光催化剂为二维纳米片自组装成的三维球状结构,其中,H_4SiW_(12)O_(40)与Bi_2WO_6不是简单的固载关系而是在超临界水热条件下生成一种新的晶相,正是由于这种晶相的存在,使得H_4SiW_(12)O_(40)牢固固载在Bi_2WO_6光催化剂本体上的同时,对光生载流子进行了有效疏导,提升了H_4SiW_(12)O_(40)/Bi_2WO_6光催化剂的使用寿命和光催化活性。本研究针对光催化剂制备周期与晶形发育的矛盾,将超临界水热技术与光催化剂模板导向合成技术有机结合,在获得良好晶形异质结构H_4SiW_(12)O_(40)/Bi_2WO_6光催化剂的同时明显缩短了光催化剂的制备周期,从而降低了催化剂的制备成本,攻克了光催化剂工业化应用的主要矛盾,所制备的H_4SiW_(12)O_(40)/Bi_2WO_6光催化剂轻质油脱氮效率达97%以上。     

Catalytic decomposition of H2O2 on Co3O4 doped with MgO and V2O5

The effects of doping of Co₃O₄with MgO (0.4–6 mol%) and V₂O₅ (0.20–0.75 mol%) on its surface and catalytic properties were investigated using nitrogen adsorption at −196°C and decomposition of H₂O₂ at 30–50°C. Pure and doped samples were prepared by thermal decomposition in air at 500–900°C, of pure basic cobalt carbonate and basic carbonate treated with different proportions of magnesium nitrate and ammonium vanadate. The results revealed that, V₂O₅ doping followed by precalcination at 500–900°C did not much modify the specific surface area of the treated Co₃O₄ solid. Treatment of Co₃O₄ with MgO at 500–900°C resulted in a significant increase in the specific surface area of cobaltic oxide. The catalytic activity in H₂O₂ decomposition, of Co₃O₄ was found to suffer a considerable increase by treatment with MgO. The maximum increase in the catalytic reaction rate constant (k) measured at 40°C on Co₃O₄ due to doping with 3 mol% MgO attained 218, 590 and 275% for the catalysts precalcined at 500, 700 and 900°C, respectively. V₂O₅-doping of Co₃O₄ brought about a significant progressive decrease in its catalytic activity. The maximum decrease in the reaction rate constant measured at 40°C over the 0.75 mol% V₂O₅-doped Co₃O₄ solid attained 68 and 93% for the catalyst samples precalcined at 500 and 900°C, respectively. The doping process did not modify the activation energy of the catalyzed reaction but much modified the concentration of catalytically active constituents without changing their energetic nature. MgO-doping increased the concentration of CO³⁺–CO²⁺ ion pairs and created Mg²⁺–CO³⁺ ion pairs increasing thus the number of active constituents involved in the catalytic decomposition of H₂O₂. V₂O₅-doping exerted an opposite effect via decreasing the number of CO³⁺–CO²⁺ ion pairs besides the possible formation of cobalt vanadate.     

光催化氧气还原制备H2O2

H2O2广泛应用于化工和环保领域,其分解的唯一产物是水,有利于生产与自然生态系统的协调可持续发展.工业上H2O2的合成主要是通过蒽醌法间接合成,该方法能耗大,污染环境.而直接由H2与O2混合制备H2O2,具有极大的安全风险,且需要消耗大量H2.通过光催化技术将O2和H2O转化成H2O2的方法,避免了H2与O2的直接混合...     

H2O2-responsive theranostic nanomedicine

This review summarizes and discusses the very-recent developments of H₂O₂-responsive theranostic nanoplatforms for versatile biomedical applications, including diagnostic imaging, attenuating tumor hypoxia, enhancing the therapeutic effi ciency of photodynamic therapy/radiation therapy/chemotherapy and theranostic of inflammation/diabetic. It is highly believed that H₂O₂-responsive theranostic nanomedicine will be extensively developed a new specifi c and effi cient theranostic modality to benefi t the personalized biomedicine in the near future.     

燃煤烟气脱硫脱硝技术研究进展

综述了燃煤烟气脱硫脱硝技术研究进展,分析比较了目前烟气脱硫脱硝技术的优缺点;指出燃煤烟气脱硫脱硝技术是目前国内外燃煤烟气研究领域的一大热点,其中活性焦烟气脱硫脱硝技术是投入小、成本低、效益好的应用新技术,应用推广前景广阔.     

离子液体/H_2O_2体系脱硫实验研究

选取四种不同种类离子液体(ILs),1-丁基-3-甲基咪唑溴化物([Bmim]Br)、1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF_4)、1-丁基-3-甲基咪唑硫酸氢盐([Bmim]HSO_4)、1-丁基-3-甲基咪唑磷酸二氢盐([Bmim]H_2PO_4)与30%H_2O_2溶液在温和条件下对两种高硫脱灰煤样(LS、QX)进行脱硫实验研究。用化学法测定脱硫前后煤样形态硫含量,并利用傅里叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)及热重(TG)对脱硫前后的煤样进行表征。结果表明,离子液体的加入使H_2O_2氧化脱硫能力增强,煤中硫铁矿硫和有机硫化物硫被显著脱除;经ILs/H_2O_2体系作用后的煤样中小粒径的颗粒减少,颗粒间的缝隙增大,煤表面的凹坑明显,热重实验结果表明,ILs/H_2O_2体系作用后的煤样相对于原煤热失重增大,部分挥发性物质释放峰温提前。     

Factors influencing decomposition of H2O2 over supported Pd catalyst in aqueous medium

Since H₂O₂ decomposition can result in selectivity/yield loss in the direct H₂O₂ synthesis process from H₂ and O₂ over supported Pd catalysts, it is important to have an enhanced understanding about the factors affecting the H₂O₂ decomposition reaction. Herein, detailed studies have been undertaken to investigate the influence of different factors, such as (a) nature and concentration of acid in reaction medium, (b) nature and concentration of halide in presence and absence of acid in reaction medium, (c) pretreatment procedures and (d) catalyst modification by incorporation of different halides, on the H₂O₂ decomposition reaction over a 5% Pd/C catalyst in aqueous medium at 25 °C. This study has shown that the H₂O₂ decomposition activity is profoundly influenced by all the above factors. The effectiveness of the acids in suppressing the H₂O₂ decomposition activity decreased in the following order: hydroiodic acid > hydrobromic acid > hydrochloric acid  acetic acid > phosphoric acid > sulfuric acid > perchloric acid. The ability of the acid to decrease the H₂O₂ decomposition activity was found to very strongly depend on the nature of its associated anion. Halides, such as iodide, bromide and chloride were particularly effective in suppressing the H₂O₂ decomposition activity. Oxidation pretreatment of the catalyst was found to strongly suppress its H₂O₂ decomposition activity, while a reduction treatment was found to promote its activity. A gradual decrease in the H₂O₂ decomposition activity of the catalyst was observed with each successive usage due to in situ sub-surface oxidation of Pd by H₂O₂. Halide incorporation either via the reaction medium or prior catalyst modification had a similar qualitative effect on the H₂O₂ decomposition activity.     

Mg-Al LDH的制备及Mg-Al LDH/H2O2体系降解水中环丙沙星的研究

分别以MgO和Al(OH)3为镁源及铝源,采用水热法制备Mg-Al LDH,研究了水热温度和氢氧化钠浓度对水热产物纯度的影响。结果显示在NaOH/MgO/Al(OH)3/(Na₂CO₃)摩尔比为2∶1∶0.5∶0.25,水热反应温度在120~150℃,反应12 h,可以得到纯相Mg-Al LDH。进一步以所制备的Mg-Al LDH为吸附剂,H₂O₂为氧化剂。系统研究了Mg-Al LDH/H₂O₂体系溶液pH、H₂O₂用量、污染物浓度、反应温度、反应时间等因素对Mg-Al LDH/H₂O₂体系降解水体中环丙沙星效果的影响。当Mg-Al LDH用量为0.05 g,H₂O₂用量为2 mL,系统pH为6.98,反应温度为35℃,环丙沙星浓度为30 mg·L^-1时,反应13 min环丙沙星的降解率可达97%。随着反应温度的升高,反应速率及平衡时降解率均有所提高,该过程可以用拟一级动力学方程描述,反应的表观活化能E a为19.29 kJ·mol^-1,指前因子A为0.38×10³ min^-1。Mg-Al LDHs/H₂O₂体系降解环丙沙星过程受反应速率控制,而非受传质控制。