A sulfur-tolerant Pd/CeO2 catalyst for methanol synthesis from syngas

The catalytic activity of ceria-supported Pd for selective hydrogenation of CO is well preserved in the presence of 30 ppm H2S due to the parallel oxidation of sulfur by CeO2 under standard methanol synthesis conditions. The bifunctional nature of this catalyst opens a route for the conversion of sulfur-contaminated gas streams such as the integrated gasification combined cycle syngas or biogas into liquid fuels if desulfurization by conventional means is not practical.     

亚甲基蓝-高效液相色谱法测定卷烟主流烟气中的硫化氢

建立了亚甲基蓝-HPLC测定卷烟主流烟气中硫化氢含量的方法.考察了卷烟主流烟气中硫化氢的捕集及显色条件.捕集体系为30 mmol/L醋酸锌-20 mmol/L醋酸钠溶液,显色体系为180 mmol/L硫酸、3mmol/L N,N-二甲基对苯二胺二盐酸盐、10 mmol/L硫酸铁铵.衍生产物亚甲基蓝经ZORBAX Eclipse XDB-C18(150 mm ×4.6 mm,3.5μm)分离,流动相为甲醇-甲酸-水(45∶1∶55,体积比),流速为0.8 mL/min,DAD检测波长为665 nm.在优化条件下,硫化氢在10.65～532.69 μg/L范围内的线性系数为0.99989.硫离子的加标回收率为96％ ～ 98％,RSD为2.4％～3.2％,硫化氢的检出限(MDL)为0.12μg/支.方法可用于卷烟主流烟气中硫化氢的分析测定.     

CATALYTIC PROPERTIES OF NANOFIBROUS CARBON IN SELECTIVE OXIDATION OF HYDROGEN SULPHIDE

Nanofibrous carbonaceous materials （NFC） as a new class of materials having many applications, can catalyze the selective oxidation of H2S to sulfur. The correlation between NFC structure and its activity and selectivity in H2S oxidation was determined. It is demonstrated that selectivity can be improved if NFC with more ordered structure be synthesized and the portion of the original catalyst in carbon be reduced by increasing the carbon accumulated in the catalyst.     

Fluorescein-derived fluorescent probe for cellular hydrogen sulfide imaging

In this work, a fluorescein-derived fluorescent probe for H2 S based on the thiolysis of dinitrophenyl ether is reported. This probe exhibits turn-on fluorescence imaging of H2 S in living cells and bulk solutions with excellent selectivity. The reaction mechanism was explained by means of absorption, fluorescence and HPLC–MS.     

一种可视化检测硫化氢的苯并噻唑类荧光增强型探针

以叠氮基为识别基团,合成和表征了一种苯并噻唑类荧光增强型硫化氢探针(FL),并研究了它的光谱性质.实验结果表明,FL对硫化氢有较高的选择性和灵敏度,且响应快速,抗干扰能力强,细胞毒性低,它的检出限度为8.78×10-7 mol·L-1,在He La活细胞和各种水体样品中对硫化氢的检测表明FL具有潜在的应用价值.     

离子交换色谱-脉冲安培法测定卷烟主流烟气中硫化氢

提出了离子交换色谱-脉冲安培检测法分离测定卷烟主流烟气中硫化氢的含量。样品中的硫化氢经含有100 mmol·L^-1氢氧化钠-400 mmol·L^-1乙酸钠-0.5%乙二胺-20 mmol·L^-1抗坏血酸混合溶液捕集后,以IonPacAS7阴离子交换色谱柱为分离柱、100 mmol·L^-1氢氧化钠-400 mmol·L^-1乙酸钠-0.5%乙二胺混合溶液为淋洗液洗脱,银电极为工作电极,pH/Ag/AgCl电极为复合参比电极,用脉冲安培检测法进行测定。硫离子的质量浓度在0.1～5.0 mg·L^-1范围内与其峰面积呈线性关系,检出限为1.52μg·L^-1。方法的加标回收率在92.4%～96.4%之间,测定值的相对标准偏差（n=6）在2.0%～3.3%之间。     

碘-罗丹明B荧光探针测定空气中硫化氢

碘(I~-_3)对罗丹明B具有荧光猝灭作用,使荧光信号强度减弱甚至消失,而硫化氢可将I~-_3还原为I~-,使体系荧光信号再现,据此建立了以碘-罗丹明B缔合物为荧光探针测定硫化氢含量的方法。在激发波长360 nm,发射波长580 nm条件下进行了硫化氢的荧光测定。结果表明,在0.02～14μmol·L~(-1)范围内,硫化氢浓度与其荧光强度变化值呈良好的线性关系,检测限为3.98×10~(-9) mol·L~(-1),加标回收率为97.80%～103.7%,相对标准偏差(n=6)为1.51%～1.85%。空气中硫化氢最低检出量为6.76μg/m~3。方法简便快速、准确可靠、灵敏度高,用于空气中硫化氢的含量分析。     

铁基离子液体/NHD吸收氧化H2S的反应动力学

以铁基离子液体(Fe-IL) /聚乙二醇二甲醚(NHD)为脱硫体系, 通过静态吸收反应装置研究了共溶体系吸收氧化H₂S的动力学过程. 结果表明, 纯Fe-IL脱硫体系的动力学方程可表示为r=54.62exp(-11720/RT)· c_{{\mathrm{H}}_2\mathrm{S}} ·c_Fe(Ⅲ), Fe-IL/NHD吸收氧化H₂S属于快速拟一级反应, 复配NHD后, 对Fe(Ⅲ)的反应级数随NHD复配比的增大而增大, 提高温度和NHD的复配比可强化传质过程, 提高脱硫过程的反应速率.     

H2S预处理对Ni2P/SiO2催化剂结构及氯苯加氢脱氯性能的影响

采用10% H₂S/H₂对Ni₂P/SiO₂催化剂进行预处理,利用X射线衍射、电感耦合等离子发射光谱、X射线光电子能谱、CO化学吸附、H₂程序升温脱附、NH₃程序升温脱附及活性评价等方法研究了H₂S预处理对催化剂结构和氯苯加氢脱氯反应性能的影响.结果表明,即使在873K进行H₂S预处理,Ni₂P/SiO₂催化剂体相结构及Ni₂P晶粒大小没有发生变化,但导致Ni₂P晶粒表面形成了磷硫镍相(NiP_xS_y),同时使表面溢流氢数量增加.硫物种的存在不仅阻塞了部分镍中心,使催化剂表面镍中心密度降低,也导致镍中心的缺电子性进一步增加.经H₂S预处理后Ni₂P/SiO₂催化剂上氯苯加氢脱氯反应的转化频率(TOF)明显提高,这可能与催化剂表面Ni物种的缺电子性增强及溢流氢数量增多有关.     

Theoretical Study on the Dehydrogenation Reaction of H2S by VS^＋ （^3Σ^-）

1 INTRODUCTION Interest in transition-metal sulfides arises from their significance in industrial catalysis and biolo- gy[1]. Transition-metal sulfides as versatile catalysts are often less susceptible to poisoning and show higher selectivity than their corresponding oxides[2]. In fact, the transition-metalion chemistry has been an active area for both experimental and theoretical studies[3～10]. Recently, Schwarz’s and Armentrout’s working groups[11, 12] have reported the experimenta…