中文摘要：

利用硅藻土为载体，用浸渍法制备了H6P2W18062／硅藻土复合催化剂，采用FT-IR，XRD，SEM，EDS，TG和Py-IR对其进行表征．以1，4-丁二醇液相环化脱水制备四氢呋喃反应为探针，考察其酸催化性能，并对反应条件进行优化，同时还考察了催化剂的重复使用性能．催化剂兼具有Br6nsted和Lewis酸性，当负载量为40％时磷钨酸在硅藻土表面单层覆盖，因而显示最大的总酸量，表现出最高的催化活性，在催化剂用量（以1,4．丁二醇质量计）3．2％，反应温度180℃，反应时间45min，四氢呋喃产率可达97．1％．催化剂重复使用5次，产率仍可达62．9％．UV-Vis，TG和Py-IR方法表征结果表明，活性组分溶脱流失及结焦使催化剂酸中心减小是催化剂失活的原因．与传统酸性催化剂相比，采用H6P2W18062／硅藻土作为反应催化剂不仅提高了反应产率（高于浓硫酸），简化了工艺流程，无酸腐蚀和污染问题，且催化剂无需处理可重复使用多次．

英文摘要：

Diatomite supported Dawson-type phosphotungstic acid catalysts with diferent loadings were prepared by the in- cipient impregnation method and characterized by FT-IR, UV-Vis, XRD, SEM, EDS, TG and Py-IR. Their catalytic behaviors were investigated via the cyclodehydration of 1,4-butanediol to synthesize tetrahydrofuran. The reaction conditions for tetra- hydrofuran synthesis were optimized, and the stability of H6P2W18062/Diatomite in the cyclodehydration reaction was investi- gated. The catalysts showed both Bronsted and Lewis acidity, and the catalyst with 40% n6P2WlsO62 loading had the highest total acidity and catalytic activity because of the monolayer coverage of the active species. 97.1% yield of tetrahydrofuran could be obtained under the reaction conditions of 180℃ for 45 min, catalyst amount 3.2% of 1,4-butanediol. These catalysts could be recycled and still exhibited catalytic activity with a yield of 62.9% after five cycle reactions. It was found by means of UV-Vis, TG-DTA and Py-IR that the catalyst deactivation was due to the dissolution of H6P2W18062 and decrease of the acid sites, which was caused by coking on catalyst surface. Compared with using sulfuric acid as catalyst, the present proce- dure is a green productive technology characterized by process simplification, higher yield and no corrosion for facilities. Moreover, the H6P2W18062/Diatomite can be used for many times.