类水滑石及其杂多阴离子柱撑物的合成与表面酸性研究

SYNTHESIS AND SURFACE ACIDIC PROPERTIES OF HYDROTALCITE LIKE COMPOUNDS AND THEIR POLYOXOMETALATE INTERCALATES

合成了一些类水滑石和过渡金属取代型杂多酸盐，并由此制备了相应杂多阴离子柱撑水滑石层柱材料。用ＸＲＤ，ＩＲ和元素分析等手段对合成产物进行组成和结构表征，用ＮＨ３－ＴＰＤ，Ｐｙ－ＩＲ研究了合成产物的表面酸性和酸类型，并在异丙醇反应中考察了合成物的酸碱催化行为，结果表明，水滑石和柱撑水滑石均同时存在酸碱中心，且酸碱相对强度与柱阴离子类型密切相关。杂多阴离子进入水滑石层间，同时改变了水滑石和杂多酸盐的酸强度及其分布，主要表现为酸强度的适当增强和少量Ｂ－酸中心的产生。

Hydrotalcite like compounds(HTLs),transition metal substituted polyoxometalate and their intercalates were synthesized,and characterized by XRD,IR and elemental analyses.The surface acidic properties and acidic types of the synthesized products were studied by NH 3 TPD and Py IR methods,and the acid base catalytic behaviors were examineed over isopropanol conversions.Results show that there is two kinds of active sites(acid and base) on the surface of the HTLs,and their relative strength are related to the kinds of the anion pillars.The acidic strength increases slightly and the B acidic sites are produced with the polyoxometalates intercalating into the HTLs layers.