铝粉与水反应的电化学研究

Reaction of Al Powder and Water Visa Electrochemistry Technology

为评价Al-H2O反应中铝粉的燃烧效率,从电化学角度对粒径为50nm,2μm,13μm和29μm的铝粉进行水反应研究。通过测定不同温度下铝水反应极化曲线,初步建立起使用电化学参数(腐蚀电位,腐蚀电流密度,腐蚀电位温度系数)表征铝水反应的评价体系。拟合分析了实验数据,探讨了粒径和温度对铝水反应的影响。用法拉第定律和吉布斯-亥姆霍兹方程对反应进行了电化学热力学研究。结果表明,随着铝粉粒径的减小,反应的腐蚀电位减小,反应越容易进行。当粒径小于2μm时,粒径的减小对腐蚀电位的影响更加明显。25℃下50nm的Al粉在铝水体系中燃烧效率即可达90.6%,远高于2μm Al粉的66.7%。

In order to evaluate the combustion efficiency of AI powder in Al-H2O reaction, the reaction of AI powder with particle size of 50 nm, 2 μm,13 μm and 29 μm and H2O was studied from electrochemistry. An evaluated system to characterize the Al-H2O reaction with parameters including corrosion potential, corrosion current density and corrosion potential temperature coefficient was initially established by polarization curves of Al-H2O reaction at different temperatures, The experimental data were fitted and analyzed to discuss the behaviours of Al-H2O reaction affected by particle size and temperature. The electrochemical thermodynamics of Al-H2O reaction was studied by Faraday＇s law and Gibbs-Helmholtz equation. Results show that with the reduction of particle size of AI powder, the corrosion potential （ Ecorr） of Al-H2O reaction decreases and the Al-H2O reaction easily takes place. The decrease rate of E is relatively significant when the particle size is less than 2μm. The combustion efficiency of AI powder with 50 nm is 90.6% in Al-H2O system, which is much higher than that of AI powder with 21μm at 25 ℃ （66.7%）.