The study of potassium-free sulfur-tolerant Co-Mo supported water-gas shift catalyst

水煤气变换是水蒸气（H2O）和一氧化碳（CO）反应生成二氧化碳(CO2)和氢气(H2)的一个可逆、放热反应（CO+H2O=CO2+H2）。钴钼变换催化剂主要应用于合成氨、合成甲醇和制氢行业的半水煤气变换。与传统工业变换催化剂Fe-Cr系（中温，400℃）和Cu-Zn系（低温，200℃）相比，钴钼变换催化剂的催化特性是：低温活性好，活性温区宽（160~500℃），耐硫耐毒性强。近几年，化工行业积极推广使用这类高效催化剂，Co-Mo型催化剂因此在工业上获得广泛的应用和认可。钴钼变换催化剂有两类：一类是Co-Mo-K/γ-Al2O3，用于低压（0.8~2.0MPa）低汽气比（~0.3）中温串低温变换...The water-gas shift (WGS) is a reversible, exothermic reaction of steam with carbon monoxide (CO) to produce carbon dioxide (CO2) and hydrogen (H2). The supported cobalt-molybdenum catalyst is mainly employed in the water-gas shift reaction of many industrial processes, such as ammonia synthesis, methanol synthesis and hydrogen production. Compared with iron-chromium-based shift catalyst (the opti...学位：理学硕士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：20022509

拟合实验数据的新方程——非整数幂多项式方程

将实验数据拟合成方程在科学研究和工程计算上具有十分重要的作用。目前,拟合实验数据最常用的是整数幂多项式f(x)=c_0+c_1x+c_2x~2+…+c_nx~n,但是用此多项式拟合各类数据时有时误差较大。本文提出一个新方程,即双系列非整数幂多项式g(x)=c_0+c_1x~0+…+c_kx~(ka)+c_(k+1)x~[(k+1)b]+…+c_nx~(nb),式中a,b为参数,c_i(i=0,1,2,…,n)为待定系数。在拟合各类实验数据时,新方程总是优于整数幂多项式

流动反应器催化反应转化率与温度及空速的关系式

通过实验考察了四个不同催化反应的温度 T 及空速 H_v 对流动反应器催化转化率 x 的影响:(1)柴油所含芳烃的加氢饱和;(2)甲醇分解制氢;(3)渣油加氢脱硫;(4)一氧化碳水煤气变换反应,研究了流动反应器中催化反应转化率 x 与反应温度 T 及空速 H_v 的关系。对所得实验数据进行了拟合,提出一个新的反应转化率 x 表达式,其中α为反映空速 H_v 对转化率 x 影响的参数,k′_i(i=1,2,3)为与温度有关的系数。以此关系式对实验数据的拟合结果令人满意,平均相对误差小于2.0%

高硫化氢合成气制甲硫醇新型钼基催化剂研究

研究了一系列负载型钼基催化剂催化含高硫化氢合成气制甲硫醇的性能 ,用XPS和ESR对其进行表征 .活性测试显示 ,钾促进的钼基催化剂催化的反应产物中甲硫醇成为主导产物 .几种钼基催化剂合成甲硫醇的活性大小顺序 :K2 MoO4/CoO/SiO2 >K2 MoO4/SiO2 >MoO3 /K2 CO3 /SiO2 >K2 MoS4/SiO2 >MoS2 /K2 CO3 /SiO2 .ESR表征显示 ,反应后的催化剂可以检测到“oxo Mo(V)”和“thio Mo(V)”物种 .XPS表征显示反应后催化剂中的Mo包含着Mo4+ ,Mo5+ 和Mo6+ ,S包含着S2 -,(S—S) 2 -和S6+ 三种价态 .添加CoO后 ,“oxo Mo(V)”含量减少 ,而“thio Mo(V)”含量增加 ,(S—S) 2 -物种的生成得到抑制 ,S2 -物种的量增多 .(Mo4+ +Mo5+ ) /Mo6+ 峰强度比为 0 75以及S2 -/(S—S) 2 -接近 1有利于甲硫醇的生成 .本文提出甲硫醇的合成与“Mo S K”相关联的反应机

Spectroscopic Characterization on Interaction of Gold (Au ~(3+)) Biosorption by Bacillus megaterium D01

对休眠的巨大芽孢杆菌 (Bacillusmegatherium)D0 1菌体吸附Au3 + 的作用过程进行了谱学表征 .运用AAS考察了pH、时间和温度对D0 1菌体吸附Au3 + 过程的化学动力学和热力学相关参数的影响 .D0 1菌粉中硫元素含量的EDX分析说明该菌体中对Au3 + 具有还原作用的L 半胱氨酸和蛋氨酸的含量极少 ;D0 1菌体水解后葡萄糖含量的UV vis测定说明该菌体水解产物中含有一定量的还原糖 .空白的和吸附Au3 + 的D0 1菌体的FTIR检测表明该菌体细胞壁肽聚糖层糖类化合物的羟基和肽链侧链氨基酸残基离子化羧基为吸附Au3 + 的活性基团 ;肽聚糖层部分多糖的水解产物低聚糖、二糖及单糖等还原糖的半缩醛羟基游离态醛基为电子供体 ,将Au3 + 原位还原成Au0 .葡萄糖和Au3 + 相互作用的XRD和FTIR表征证明Au3 + 是在还原糖的醛基上直接被还原成Au0Biosorptive interaction of gold with resting cell of Bacillus megatherium D01 biomass has been characterized by spectroscopic techniques. The effects of pH, time and temperature on the correlation parameters of chemical kinetics and thermodynamics of the binding reaction has been investigated through the determination of the gold ion binding to the biomass using atomic absorption spectrophotometry (AAS). The analysis for sulfur content in dry powder of the D01 biomass by energy dispersive X-ray (EDX) shows that cysteine and methionine being capable of reducing Au 3+ to Au0 is very small, whereas the glucose content in hydrolysates of the biomass analyzed by ultraviolet-visible spectrophotometry (UV-vis) indicates that the amount of the reducing sugars in the biomass is much larger than 3.33%. The Fourier transform infrared (FTIR) spectroscopy on blank and gold-loaded biomass demonstrates that the active groups such as the hydroxyl group of saccharides and the ionized carboxyl group of amino acid residues on the cell wall seem to be the sites for Au 3+ binding, and the free aldehyde group of the hemiacetalic hydroxyl group from reducing sugars, i.e. the hydrolysates of the polysaccharides, serving as the electron donor, in situ reduces the Au 3+ to Au0. X-ray powder diffractometry (XRD) and FTIR spectroscopic characterizations of the interaction of Au 3+ with glucose confirm that the reduction of Au 3+ to Au0 can directly occur in the aldehyde group of the reducing sugars

Novel Mo-based catalysts for methanethiol synthesis from high H2S-containing syngas

A series of supported Mo-based catalysts for methanethiol synthesis from high H2S-containing syngas were investigated by kinetics and XPS, ESR characterization. The activity evaluating results show that upon the potassium-promoted Mo-based catalysts, the methanethiol will become dominant product of the reaction, and the activity sequence of several Mo-based catalysts for the reaction is as follows: K2MoO4/CoO/SiO2 > K2MoO4/SiO2 > MoO3/K2CO3/SiO2 > K2MoS4/SiO2 > MoS2/K2CO3/SiO2. In the ESR characterization of the catalysts used the resonant signals of "oxo-Mo(V)" and "thio-Mo(V)" can be detected. The XPS characterization indicates that mixed valence Mo species Mo4+, Mo5+ and Mo6+ and three kinds of S species S2-, (S-S)(2-) and S6+ exist in the catalysts. As a promoter CoO was introduced into Mo-based catalysts. It was observed that the addition of CoO leads to decrease of the amount of "oxo-Mo(V) " in the catalysts, but increase of the amount of "thio-Mo(V)", which may be connected with "Mo-S-K" phase or "Co-Mo-S-K" phase, meanwhile CoO in die catalyst was found to enhance the formation of S2-, but inhibit the formation of (S-S)(2-). It was found also that the methanethiol synthesis is favored if the peak intensity ratios of (Mo4+ + Mo5+)/Mo6+ and S2-/(S-S)(2-) are kept at about 0.75 and 1 level respectively. A possible mechanism about the relationship of CH3SH formation with "Mo-S-K" phase was proposed

混合法制备Co-Mo/MgO-Al_2O_3变换催化剂的XRD和TPR表征

用混合煅烧法制备的Co Mo/MgO Al2O3一氧化碳变换催化剂,在2.0MPa及多种汽气比条件下与同类型催化剂进行活性评价比较,达到德国催化剂K8 11的活性水平.对催化剂及参比样MoO3/Al2O3、MoO3/MgO Al2O3和MgO Al2O3等进行XRD或TPR表征,结果显示Co Mo/MgO Al2O3催化剂存在MoO3、CoMoO4、MgMoO4和MgAl2O4等物种,单纯的Mo在MgO Al2O3载体上分散度比在γ Al2O3载体上低,MoO3的结晶度较高,其还原温度提高;添加Co后,MoO3的分散度得到提高.在Co Mo/MgO Al2O3催化剂的TPR谱中出现属于MoO3(624℃)和CoMoO4(805℃)的两个还原峰,该催化剂对CO变换活性的提高与CoMoO4相的生成密切相关

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies