氮化SBA-15负载高分散过渡金属用于丙烷高效直接脱氢

Nitriding SBA-15 loaded highly dispersed transition metals for efficient direct dehydrogenation of propane

以氮化法修饰的介孔二氧化硅(SBA-15)为载体,采用浸渍法制备了不同过渡金属(钴、镍、铁、铜)脱氢催化剂。通过X射线衍射光谱和N2吸附-脱附分析表明氮化后的载体仍能保持良好的介孔结构;通过扫描电子显微镜分析表明金属处于高度分散的良好状态;通过程序升温还原和X射线光电子能谱分析表明氮化SBA-15改变了金属的电子结构,增强了载体与金属之间的相互作用力。采用定量浸渍法制备了金属负载量为1%(质量分数)的脱氢催化剂,并进行了性能评价。结果表明,丙烷脱氢催化剂活性顺序由高到低依次为Co-SBA-15N900-1%、Fe-SBA-15N900-1%、Cu-SBA-15N900-1%、Ni-SBA-15N900-1%,其中Co-SBA-15N900-1%催化剂的丙烷转化率为33%,丙烯选择性为88%。

Dehydrogenation catalysts with different transition metals of Co,Ni,Fe,Cu were prepared by impregnation method with SBA-15 modified by nitridation method as carrier.The mesoporous structure of the support after nitridation was confirmed by X-ray diffraction(XRD) and N2 adsorption desorption analysis.Scanning electron microscopy(SEM) confirmed that the metal was in a good state of high dispersion.Temperature programmed reduction(H2-TPR) and X-ray photoelectron spectroscopy(XPS) proved that nitriding SBA-15 changed the electronic structure of the metal,and the interaction between the carrier and the metal was significantly enhanced.Metal-loaded samples with a content of 1% were prepared by quantitative impregnation method,and their properties were evaluated.The experimental results showed that the order of catalytic PDH activity of different metals for propane dehydrogenation was Co-SBA-15N900-1%,Fe-SBA-15N900-1%,Cu-SBA-15N900-1%,Ni-SBA-15N900-1%. The Co-SBA-15N900-1% exhibited a propane conversion of 33% and a propylene selectivity of 88%,indicating its promising utilization in industry.