气相质谱法研究Fe与CO_2-CO氧化反应动力学

Oxidation kinetics of iron and CO_2-CO by using gas mass spectrometry method

采用气相质谱在线监测反应气体成分变化的方法,研究了1273~1473 K范围内,不同比例CO2-CO混合气体对铁片恒温氧化的反应动力学.结果表明,氧化反应速率与二氧化碳分压呈线性关系,反应速率常数随CO2/CO体积比值增大而减小,铁片氧化反应的表观活化能为（137.7±15.8）k J·mol^-1.该方法得到的结果与文献相比较,结果是可靠的,表明该方法可以用来在线研究气-固反应的动力学.

The oxidation kinetics of iron sheet in CO2 -CO mixture was studied by on-line measuring the composition change of the reaction gas using a gas mass spectrometer under different CO2 partial pressures in the temperature range of 1273 to 1473 K. It is found that the oxidation rate increases linearly with CO2 paltial pressure, the rate constant decreases with the increase of COJCO vol- ume ratio, and the apparent activation energy of the oxidation of iron sheet is （137.7±15.8）k J·mol^-1. Compared with the results re- ported, this on-line mass spectrometry analysis can get reliable resuhs, so it can be used to study the gas-solid reaction kinetics.