Kinetics of heterogeneous reaction of CaCO3 particles with gaseous HNO3 over a wide range of humidity.
Kinetics of heterogeneous reaction of CaCO3 particles with gaseous HNO3 over a wide range of humidity.
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DOI：
10.1021/jp076169h
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发表时间：
2008-01
期刊：
影响因子：
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通讯作者：
Yong Liu;Elizabeth R. Gibson;J. Cain;Hai Wang;Vicki H. Grassian;A. Laskin
中科院分区：
文献类型：
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作者：
Yong Liu;Elizabeth R. Gibson;J. Cain;Hai Wang;Vicki H. Grassian;A. Laskin
采用颗粒-基底滞止流反应器（PS-SFR）研究了气态硝酸（HNO 3）与碳酸钙（CaCO 3）颗粒的非均相反应动力学。该技术利用衬底沉积，隔离，和窄分散的颗粒暴露于HNO 3/H2O/N2的气体混合物中，然后使用计算机控制的扫描电子显微镜与能量色散X射线分析（CCSEM/EDX）对单个反应颗粒进行微量分析。第一系列实验在大气压、室温和恒定相对湿度（40%）下进行，中值干颗粒直径Dp = 0.85 μ m，颗粒负载密度2 × 104 /= 0.06（x3//2）。在第二个系列的实验中，HNO 3吸收相同大小的碳酸钙颗粒上进行了检查，在较宽的范围内的相对湿度，从10至80%。发现净反应概率随着相对湿度的增加而增加，从RH = 10%时的gammanet >/= 0.003增加到80%时的0.21。
Heterogeneous reaction kinetics of gaseous nitric acid (HNO3) with calcium carbonate (CaCO3) particles was investigated using a particle-on-substrate stagnation flow reactor (PS-SFR). This technique utilizes the exposure of substrate deposited, isolated, and narrowly dispersed particles to a gas mixture of HNO3/H2O/N2, followed by microanalysis of individual reacted particles using computer-controlled scanning electron microscopy with energy-dispersive X-ray analysis (CCSEM/EDX). The first series of experiments were conducted at atmospheric pressure, room temperature and constant relative humidity (40%) with a median dry particle diameter of Dp = 0.85 mum, particle loading densities 2 x 104 /= 0.06 (x3//2). In a second series of experiments, HNO3 uptake on CaCO3 particles of the same size was examined over a wide range of relative humidity, from 10 to 80%. The net reaction probability was found to increase with increasing relative humidity, from gammanet >/= 0.003 at RH = 10% to 0.21 at 80%.