Co_3O_4的氢还原过程动力学研究

KINETICS OF REDUCTION OF Co_3O_4 BY HYDROGEN

应用等温和非等温热重分析法研究了 Ｃｏ３Ｏ４的氢还原过程动力学，得出两种条件下过程均分为 Ｃｏ３Ｏ４还原为 ＣｏＯ和 ＣｏＯ还原为 ＣＯ两个步骤， 二步骤均为界面化学反应控速在 ５２３─６０３ Ｋ等温及 ５０３─５８９ Ｋ非等温条件下， Ｃｏ３Ｏ４还原为 ＣｏＯ步骤的表观活化能均为 １３３ ｋＪ／ｍｏｌ； ５２３—６０３ Ｋ等温还原 ＣｏＯ为 Ｃｏ步骤的表观活化能为 ８７．５ ｋＪ／ｍｏｌ．

The kinetics of reduction of Co3O4 by hydrogen has been studied using the thermogravimetric technique isothermally and non-isothermally. It has been confirmed that the whole reduction process under both iso- and noniso-thermal conditions are composed of two interfacial chemical reaction controlled steps: the reduction of Co3O4 to CoO and CoO to Co. The activation energies of the reduction of Co3O4 to CoO obtained from isothermal TGA measurements in the range of 523603 K and from non-isothermal TGA measurements in the range of 503──589 K take the same value of 133 kJ/mol. The activation energy of the reduction of CoO to Co obtained from isothermal TGA measurements in the range of 523──603 K is 87.5 kJ/mol.