用于CO_2加氢合成甲醇的超细CuO-ZnO/SiO_2-ZrO_2催化剂

ULTRAFINE CuO ZnO/SiO 2 ZrO 2 CATALYSTS FOR SYNTHESIS OF METHANOL FROM CO 2 HYDROGENATION

用溶胶凝胶法制备了ＣｕＯＺｎＯ／ＳｉＯ２ＺｒＯ２复合氧化物催化剂，使用ＩＲ、ＸＲＤ、ＴＥＭ和ＢＥＴ等手段对催化剂的结构及表面性能进行了表征，考察了ＺｒＯ２对该体系的表面性质、结构、ＣｕＯ分散状态以及二氧化碳加氢合成甲醇的催化性能的影响．结果表明，该体系催化剂的比表面积大，活性组分分散均匀．活性组分的结晶相为ＣｕＯ，晶粒小于１６ｎｍ，并具有较高的甲醇选择性及反应活性．ＺｒＯ２对改善催化剂的性质及ＣｕＯ的结晶粒度有重要的作用．

A series of CuO ZnO/SiO 2 ZrO 2 ultrafine catalysts were prepared by sol gel method. The catalytic performance of these catalysts for CO 2 hydrogenation were investigated in a microreactor GC system, under the conditions of 513 K, 2 0 MPa, CO 2/H 2 mole ratio=3 0 and SV=2000 h -1 . The results showed that these CuO ZnO catalysts have higher conversion of CO 2 and better selectivity for methanol (CO being the only byproduct) than those catalysts prepared by precipitation and impregnation. CuO ZnO ultrafine catalysts were characterized by IR, BET, XRD and TEM. The results showed that they have high surface area (250～460 m 2/g), narrow pore distribution and high dispersion of active components. ZrO 2 neither combines with SiO 2, nor exists in the crystal phase. As the content of ZrO 2 increases, the specific surface area and specific pore volume of the catalysts decrease. So it can be inferred that ZrO 2 entered the spacing of the skeleton structure of SiO 2 as a “structure adjustor”. A portion of ZrO 2 covering the surface of CuO particle leads to the decreasing of active surface area, thus the catalytic activity declines as the content of ZrO 2 increases.