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在常压和２５０℃下，考察了涂层ＴｉＯ_２改性铜催化剂上甲醇脱氢生成甲酸甲酷的活性和选择性以及催化剂的稳定性．结果表明，涂层ＴｉＯ２明显提高了铜催化剂的活性和稳定性．在所考察的铜催化剂中，以Ｃｕ／ＴｉＯ２／Ａｌ２Ｏ３的催化活性最高，甚至高于离子交换法制备的Ｃｕ（ｅｘ）／ＳｉＯ３催化剂．ＸＰＳ分析表明，Ｃｕ／ＴｉＯ２／Ａｌ２Ｏ３中存在着两种化学环境不同的Ｃｕ（０），即负载在γ－Ａｌ２Ｏ３和ＴｉＯ２－Ａｌ２Ｏ３表面上的Ｃｕ（０）．涂层ＴｉＯ２使ＣｕＯ／Ａｌ２Ｏ３和ＣｕＯ／ＳｉＯ２中ＣｕＯ的还原温度降低，还原度增大，ＣｕＯ单层分散量增加．在反应气氛中，由于催化剂表面铜的迁移聚集、表面积炭、比表面降低等因素，因而导致催化剂失活．
Under atmospheric pressure and 250 ℃, the catalytic activity and selectivity of methanol dehydrogenation to formic acid metathanol on the coated TiO 2 modified copper catalysts were investigated. The results show that the coated TiO2 significantly improves the activity and stability of the copper catalyst. Among the investigated copper catalysts, the catalytic activity of Cu / TiO2 / Al2O3 was the highest, even higher than Cu (ex) / SiO3 catalyst prepared by ion exchange method. XPS analysis showed that there are two Cu (0) in Cu / TiO2 / Al2O3 with different chemical environments, namely Cu (0) supported on the surface of γ-Al2O3 and TiO2-Al2O3. The coating TiO2 reduced the reduction temperature of CuO in CuO / Al2O3 and CuO / SiO2, the reduction degree increased and the CuO monolayer dispersion increased. In the reaction atmosphere, catalyst deactivation occurs due to copper migration and aggregation on the surface of the catalyst, surface carbon deposition, and specific surface area reduction.