Kinetic Study of the Reactions of AlO with H₂O and H₂; Precursors to Stellar Dust Formation

AlO is relatively abundant around oxygen-rich Asymptotic Giant Branch (AGB) stars, where it can react with major gas-phase species such as H2 and H2O to form AlOH. These Al-containing are the likely precursors of refractory alumina nanoparticles, which may provide nuclei for dust formation. In present study, kinetics these reactions were measured from 295 780 K using pulsed laser photolysis Al(C5H7O2)3, time-resolved induced fluorescence detection AlO. The experimental results interpreted quantum chemistry calculations a Master Equation solver multiple energy wells. For recombination reaction + (+ N2) ? Al(OH)2, log10(krec,0/cm6 molecule–2 s–1) = ?32.9185 8.80276 log10(T) – 2.4723(log10(T))2; log10(krec,?/cm3 molecule–1 ?19.4686 7.62037 1.47214(log10(T))2; Fc 0.28 (uncertainty ±13% 760 K). bimolecular reactions, k(AlO AlOH OH) (3.89 ± 0.47) × 10–10 exp(?(1295 150)/T) H) (5.37 0.52) 10–13 (T/300)(2.77 0.19) exp(?(2190 110)/T) cm3 s–1. Rate coefficients Al H, H or H2O, absorption cross sections calculated theoretically. an O-rich AGB star was then investigated ?-trajectory model, predicts that beyond two stellar radii shows relative abundance very sensitive rate.