pstrongAbstract./strong The heterogeneous uptake of methylamine (MA) onto (NHsub4/sub)sub2/subSOsub4/sub, NHsub4/subHSOsub4/sub, NHsub4/subNOsub3/sub and NHsub4/subCl was investigated using a Knudsen cell reactor coupled to a quadrupole mass spectrometer, in situ Raman spectrometer and theoretical calculations. Exchange reactions were observed between MA and NHsub4/subNOsub3/sub, (NHsub4/sub)sub2/subSOsub4/sub, and NHsub4/subCl were observed at 298 K. Simple acid-base reaction for MA was found taking place on NHsub4/subHSOsub4/sub. CHsub3/subNHsub3/subNOsub3/sub and CHsub3/subNHsub3/subCl are not stable at low pressure and have higher dissociation vapor pressure than methylammonium sulfate. The observed uptake coefficients of MA on (NHsub4/sub)sub2/subSOsub4/sub, NHsub4/subHSOsub4/sub, NHsub4/subNOsub3/sub and NHsub4/subCl at 298 K were measured to be 6.30?±1.03??10supa??3/sup, 1.78?±0.36??10supa??2/sup, 8.79?±1.99??10supa??3/sup and 2.29?±0.28??10supa??3/sup, respectively. A linear free energy relationship was found for the heterogeneous reactions between MA and NHsub4/subCl, (NHsub4/sub)sub2/subSOsub4/sub and NHsub4/subNOsub3/sub. Namely, the natural logarithm of uptake coefficients of MA on these ammonium salts is linearly related to the electrostatic potential of the H atom in the NHsub4/subsup+/sup group./p.
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机译：> >摘要。甲胺（MA）在（NH 4 ） 2 SO 4 上的异质吸收，研究了NH 4 HSO 4 ，NH 4 NO 3 和NH 4 Cl使用与四极质谱仪耦合的Knudsen细胞反应器，原位拉曼光谱仪和理论计算。观察到MA与NH 4 NO 3 ，（NH 4 ） 2 SO 4之间的交换反应，在298 K处观察到NH 4 Cl。MA的简单酸碱反应发生在NH 4 HSO 4 子>。 CH 3 NH 3 NO 3 和CH 3 NH 3 Cl不稳定在低压下具有比硫酸甲基铵更高的离解蒸气压。 MA对（NH 4 ） 2 SO 4 ，NH 4 HSO 4的吸收系数，NH 4 NO 3 和NH 4 Cl在298 K下测得为6.30？±1.03 ?? 10 a ?? 3 ，1.78？±0.36 ?? 10 a ?? 2 ，8.79？±1.99 ?? 10 a ?? 3 和2.29？ ±0.28 ?? 10 a ?? 3 。发现MA与NH 4 Cl，（NH 4 ） 2 SO 4 < / sub>和NH 4 NO 3 。即，这些铵盐上MA吸收系数的自然对数与NH 4 + 组中H原子的静电势线性相关。 。
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