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利用热分析、X 射线衍射分析和透射电子显微镜技术研究了CuO-ZnO-Al_2O_3-V_2O_5低压合成甲醇催化剂的还原条件与其结构和性能之间的关系。实验结果表明:催化剂的还原分为慢速、快速、再慢速三个阶段。催化剂在140℃、含2%H_2的N_2、H_2混合气中恒温还原有生成Cu~+为主的阶段,还原后的物相中有Cu_2O 存在。催化剂的还原不同于纯CuO 的还原,还原后的催化剂经再氧化后已恢复不到原有的还原程度。此外,还对不同温度下还原后催化剂的活性进行了评价与关联。
The relationship between the reduction conditions and the structure and properties of CuO-ZnO-Al_2O_3-V_2O_5 low-pressure methanol catalysts was investigated by means of thermal analysis, X-ray diffraction and transmission electron microscopy. The experimental results show that the reduction of catalyst is divided into three stages: slow, fast and then slow. At 140 ℃, the mixture of N2 and H2 containing 2% H2 was heated to a temperature at which Cu2 + was the main phase, and Cu2 + existed in the reduced phase. The reduction of the catalyst is different from the reduction of the pure CuO. The reduced catalyst has not recovered its original degree of reduction after reoxidation. In addition, the activities of the catalysts after reduction at different temperatures were also evaluated and correlated.