Ru/SBA-15的制备及其对水煤气变换反应的催化作用

制备了中孔分子筛SBA-15,以SBA-15为载体采用真空浸渍法制备了负载型Ru基水煤气变换反应的催化剂。利用透射电子显微镜、X-射线粉末衍射等方法对样品进行了表征。结果表明,合成的SBA-15分子筛孔径约为8 nm,粒径约为1 nm的Ru纳米粒子均匀分布在分子筛孔道中,添加适量的La2O3助剂可以显著提高催化剂的低温活性。当Ru和La2O3的负载量分别为4%和8%时,R4L8/SBA-15催化剂对CO转化率在255℃和265℃下分别达到56%和98%。

Preparation of Ru/SBA-15 mesoporous silica catalyst and its catalysis for WGS reaction

The supported Ru-based catalyst promoted by lanthanum oxide was prepared by impregnating the SBA-15 carrier with aqueous Ru(Ac)_3 and La(NO_3)_3 solution using vacuum absorbing method. The as-prepared catalysts were investigated by means of X-ray powder diffraction, transmission electron microscopy, and catalytic activity measurement for water-gas shift reaction. SBA-15 silica synthesized with P_123 by reaction at 80℃ for 24h proved to be a mesoporous product with a mean pore size of 8nm. Metallic Ru was well dispersed on SBA-15 carrier as nanoparticles in 1nm size. The results indicated that the optimized content of ruthenium and lanthanum oxide in catalyst is 4% and 8%, respectively. Under conditions of SV=2000h ~(-1) and V_(steam)/V_(gas)=1, the CO conversion is 56% at 255℃ and 98% at 265℃ for catalyst R_4L_8/SBA-15.