在涂层TiO_2改性铜催化剂上甲醇脱氢制甲酸甲酯  

DEHYDROGENATION OF METHANOL TO METHYL FORMATE ON COPPER CATALYSTS SUPPORTED ON TITANIA COATED ALUMINA AND SILICA

作　　者：刘昭铁[1] 陆大勋[1] 郭志英[1] 

机构地区：[1]中国科学院山西煤炭化学研究所

出　　处：《Chinese Journal of Catalysis》1994年第1期9-12,共4页催化学报（英文）

基　　金：国家自然科学基金;北京市中关村地区联合分析测试中心资助

摘　　要：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．Titania coated alumina and silica were used as supports for coppercatalysts in the dehydrogenation of methanol to methyl formate. Thecatalysts with TiO2coated and uncoated support were characterized andtheir activity,selectivity and stability were Studied at 250℃ and normalpressure. It is found that titania coating improves significantly the activity and stability of the copper catalysts. It also lowers the reductiontemperature, increases the degree of reduction of CuO on Al2O3 andSiO2 and improves the monolayer spreading of CuO on the supports.Among the catalysts studied, Cu/TiO2 /Al2O3 shows the highest activity,selectivity and stability. Two Cu(0) species were detected by XPS,probably existing in different chemical environments, namely Cu(0 ) onalumina and another on TiO2-Al2O3. Decrease in surface area and Cu/Al and Cu/Si ratios and increase in surface carbon were observedafter reaction, indicating the occurrence of Cu aggregation and coking.

关 键 词：铜催化剂 TIO2 甲醇脱氢 甲酸甲酯 

分 类 号：O623.611[理学—有机化学]