利用雷射光解－原子吸收光譜技術在衝擊波管中測量N2O熱分解速率，以及在1318-2436 K的溫度下之O + HCl的反應速率

Abstract

本研究以新裝設之衝擊波管配合以雷射光解－原子共振吸收光譜法研究高溫(＞1300 K)之反應動力學，我們測得在1693 – 3804 K溫度下N2O的熱分解反應速率常數值為k4-2(T) = (4.83 ± 0.04) × 10-10 exp[(-53.77 ± 0.79) kcal mol-1/RT] cm3 molecule-1 s-1。 N2O + Ar --> N2 + O + Ar* (4-2) 進行氧原子和氯化氫反應之研究時，先在衝擊波管中製造出高溫，再以248 nm的雷射光光解SO2產生氧原子來進行反應： SO2 + h ν(248 nm) --> SO + O (4-9) O + HCl --> OH + Cl (4-10) 我們得到此反應在1318 – 2436 K間之速率常數值為： k4-10(T) = (1.02 ± 0.01) × 10-19 exp[(-18.60 ± 0.70) kcal mol-1/RT] cm3 molecule-1 s-1

A shock tube coupled with laser photolysis-atomic resonance absorption spectrophotometry(ARAS) was built to study the reaction kinetics at high temperatures . The absolute rate constants of the thermal decomposition of N2O ( N2O + Ar à N2 + O + Ar* ) in the temperature range 1693－3804 K were determined as k(T) = (4.83±0.04) × 10-10 exp[(-53774 ± 791) kcal mol-1/RT] cm3 molecule-1 s-1, which agreed well with published results . In the study of O + HCl reaction , oxygen atoms were produced by photolysing SO2 at 248 nm behind the reflected shock wave , SO2 + hν(248 nm) --> SO + O (4-9) followed by subsequent reaction of interest : O + HCl --> OH + Cl (4-10) We obtained k4-10(T) = (1.02±0.01) × 10-19 exp[(-18.60 ± 0.70)kcal mol-1/RT]cm3 molecule-1 s-1 between 1318 and 2436 K .