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《Chemical physics letters》1986,126(2):149-152
The flash photolysis-visible absorption technique has been used to measure rate constants for the reaction NO + NO3 → 2NO2 (1) over the temperature range 224–328 K. The temperature dependence of the rate constant is given by the expression k1(T) = (1.59 ± 0.32) × 10−11exp(122/T) cm3 molecule−1 s−1 where the stated uncertainties refer to the ± 2σ limits from both random and systematic errors. 相似文献
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Dr. Jiao-Jiao Chen Dr. Qing-Yu Liu Si-Dun Wang Prof. Dr. Xiao-Na Li Prof. Dr. Sheng-Gui He 《Chemphyschem》2023,24(4):e202200743
A fundamental understanding on the dynamically structural evolution of catalysts induced by reactant gases under working conditions is challenging but pivotal in catalyst design. Herein, in combination with state-of-the-art mass spectrometry for cluster reactions, cryogenic photoelectron imaging spectroscopy, and quantum-chemical calculations, we identified that NO adsorption on rhodium-cerium bimetallic oxide cluster RhCeO2− can create a Ce3+ ion in product RhCeO2NO− that serves as the starting point to trigger the catalysis of NO reduction by CO. Theoretical calculations substantiated that the reduction of another two NO molecules into N2O takes place exclusively on the Ce3+ ion while Rh behaves like a promoter to buffer electrons and cooperates with Ce3+ to drive NO reduction. Our finding demonstrates the importance of NO in regulating the catalytic behavior of Rh under reaction conditions and provides much-needed insights into the essence of NO reduction over Rh/CeO2, one of the most efficient components in three-way catalysts for NOx removal. 相似文献
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The NO2 NO2^- electron transfer reaction was studied with DFT-B3LYP method at 6-311 G^* basis set level for the eight selected structures:four species favor the structure of “head to head”.The geometry of transition state was obtained by the linear corrdinate method.Three parameters,non-adiabatic activation energy(Ead),coupling matrix element(Hif) and reorganization energy(λ) for electron transfer reaction can be calculated.According to the reorganization energy of the ET reaction,the values obtained from George-Griffith-Marcus (GGM) method(the contribution only from diagonal elements of force constant matrix) are larger than those obtained from Hessian matrix method(including the contribution from both diagonal and off-diagonal elements), which suggests that the coupling interactions between different vibrational modes are important to the inner-sphere reorganization energy for the ET reactions in gaseous phase.The value of rate constant was obtained by using above three activation parameters. 相似文献
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建立了血清NO的间接测定方法。采用正交设计法[L9(3^4)]观察不同还原剂及其用量,原时间和温度对NO3^-还原率的影响。最佳还原条件为400mg镀铜镉粒室温还原120min,还原率达97%以上。方法简便易行,不需昂贵设备,准确度较高,适合一般实验室用于各种生物医学实验中NO的间接测定。 相似文献
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无色NO和空气中O2 一经接触即生成红棕色的NO2 。NO + 12 O2 =NO2 ΔrHm =- 5 6 5kJ/mol,ΔrSm =- 73J/K·mol,不同温度下的平衡常数见表 1。由平衡常数知 :低于 15 0℃ ,NO可以较完全转化为NO2 ,高于 80 0℃事实上“不能”生成NO。表 1 平衡常数T/K 2 9840 0 5 0 0 70 0 77410 0 10 73K 1 4× 10 6 4 3× 10 2 1 3× 10 2 2 41 0 0 14 9 4× 10 - 2 NO和O2 转化成NO2 需要时间 ,如原料气中NO为 9 92 % (体积 )、O2 为 5 6 8% (体积 ) ,在不同温度、压强下 ,NO转化速度和转化所需时… 相似文献
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Na_2O_2与NO不能反应吗郭怀亮(河北万全中学076250)在近几年的一些化学刊物上[‘1,很推崇这样一种题目:让一定体积的CO。和NO混合气体通过足量的Na。O。后,缩小到一定体积,推测原混合气体中CO。和NO的可能体积比。解题依据是:CO。与N... 相似文献
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低温等离子体转化NO/O2/N2气氛中NO的实验研究 总被引:1,自引:0,他引:1
通过建立低温等离子体实验系统, 研究了介质阻挡放电型低温等离子体反应器作用于NO/O2/N2混合气体系时, NO, O2初始浓度对NO的转化效率的影响以及NOx, O3浓度随能量密度的变化关系. 低温等离子体作用于NO/O2/N2混合气体系时, NO同时发生氧化还原反应, 氧化反应占主导地位, 大部分NO转化为NO2; NO转化率随O2, NO初始浓度增大而降低, 能量密度在450~600 J/L时转化率较高; 产生的O3浓度随能量密度的增大呈先增后减的趋势. 相似文献
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采用程序升温脱附、在线质谱和原位漫反射红外光谱等手段, 比较了 NO 和 NO2 在 V2O5 及 V2O5/AC 催化剂表面的选择催化还原 (SCR) 反应行为. 结果表明, 氨以质子态 NH4+和共价态 NH3 分子两种形态吸附于纯 V2O5 表面, V=O 为氨的主要吸附活性位. 无氧状态下, NO 和 NO2 皆可与吸附于 V2O5 表面的 NH3 反应, 并且 NO2 与吸附态 NH3 的反应活性高于 NO. 但在 V2O5/AC 催化剂表面, 同样在无氧条件下, NO 几乎不与吸附态 NH3 反应, 而 NO2 却可以反应并生成 N2. 在 V2O5/AC 表面, NO 很容易被气相 O2 氧化为 NO2, 然后参与 SCR 反应. 可见, NO2 是 NO 在 V2O5/AC 表面发生 SCR 反应的中间体. 相似文献
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H+CH3NO2H2+CH2NO2反应途径和变分速率常数计算研究 总被引:1,自引:0,他引:1
采用MP2(FULL)/6-311G**从头算方法, 优化了H+CH3NO2H2+ CH2NO2反应的过渡态结构, 得出该反应的正逆反应的活化位垒分别是82.73和57.14 kJ*mol-1. 沿IRC分析指出该反应是一个H-H键生成和C-H键断裂的协同反应, 而且在反应途径上存在一个引导反应进行的振动模式, 这一反应模式引导反应进行的区间在-0.7~0.2( amu)1/2*a0之间; 在1 000~1 400 K温度范围内, 运用变分过渡态理论(CVT), 计算了该反应的速率常数, 计算结果与实验相一致. 相似文献
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据NO2与鲁米诺在碱性条件下发生化学发光反应.产生波长为425nm的蓝色光辐射的原理,制作了一种快速鉴定NO2的简易探头。由此建立了一种灵敏、简便、实用的NO2的化学发光测定法。 相似文献
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Cong-yun Shi Feng Dong Shuo Sun Hao Zhang Li Guo Ji-kang Feng Fan-ao Kong 《化学物理学报(中文版)》2007,20(1):31-36
The elementary reaction of the CH3 radical with NO2 was investigated by time-resolved FTIR spectroscopy and quantum chemical calculations. The CH3 radical was produced by laser photolysis of CH3Br or CH3I at 248 nm. Vibrationally excited products OH, HNO and CO2 were observed by the time-resolved spectroscopy for the first time. The formation of another product NO was also verified. According to these observations, the product channels leading to CH3O+NO, CH2NO+OH and HNO+H2CO were identified. The channel of CH3O+NO was the major one. The reaction mechanisms of the above channels were studied by quantum chemical calculations at CCSD(T)/6-311++G(df,p)//MP2/6-311G(d,p) level. The calculated results fit with the experimental observations well. 相似文献
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TEA法测定NO2的反应机理研究 总被引:4,自引:0,他引:4
应用FABMS、NMR、IR、HPLC和紫外吸收光谱研究了室温下三乙醇胺与较高浓度NO2(2.48%)的反应情况,证明反应产物为三乙醇胺硝酸盐和三乙醇胺亚硝酸盐,提出了可能的反应机理,为TEA法监测空气中NO2的浓度提供了依据. 相似文献
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