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采用固相合成法制备了ZnO-ZrO2载体,并采用浸渍法制备了镍基催化剂,以噻吩加氢脱硫反应为探针考察了Co、Mo的掺杂对Ni/ZnO-ZrO2催化性能的影响.采用NH3吸附红外光谱(IR)、程序升温脱附(TPD)、程序升温还原(TPR)、X射线衍射(XRD)等技术对催化剂进行了表征.研究结果表明,ZnO-ZrO2复合载体对噻吩加氢脱硫反应有一定的活性,反应温度为400℃时噻吩转化率为6.4%;Co的加入提高了Ni/ZnO-ZrO2的催化活性,噻吩转化率可达97.3%;相反,Mo的掺杂则降低了Ni/ZnO-ZrO2的催化活性,噻吩转化率为65.0%.这是由于Co的掺杂使活性组分Ni分散度提高,氧化态的Ni变得容易还原,在同样的还原条件下催化剂表面有更多的活性中心;而Mo掺杂则使Ni/ZnO-ZrO2催化剂中氧化态的Ni变得难以还原,部分以NiO形式存在,活性中心数量减少.三种催化剂表面均存在L酸中心,Co掺杂使Ni/ZnO-ZrO2催化剂表面弱酸中心和中等强度酸中心的强度及数量均增大,Mo掺杂则减弱了催化剂表面弱酸中心和中强酸中心的强度,对其酸量则影响不大.
The ZnO-ZrO2 carrier was prepared by the solid-phase synthesis method and the Ni-based catalyst was prepared by impregnation method. The influence of Co and Mo doping on the catalytic performance of Ni / ZnO-ZrO2 was investigated by using thiophene hydrodesulfurization reaction. The catalysts were characterized by NH3-IR spectroscopy, temperature programmed desorption (TPD), temperature programmed reduction (TPR) and X-ray diffraction (XRD) Hydrogen desulfurization reaction has a certain activity, the reaction temperature is 400 ℃, the thiophene conversion rate is 6.4%; The addition of Co improves the catalytic activity of Ni / ZnO-ZrO2, thiophene conversion rate of up to 97.3%; on the contrary, the doping of Mo Reducing the catalytic activity of Ni / ZnO-ZrO2, the conversion rate of thiophene was 65.0% .This is due to the doping of Co so that the active component Ni dispersion increases, the oxidation state of Ni becomes easy to reduce, under the same reduction conditions, the catalyst The surface has more active centers; while the Mo doping makes the Ni / ZnO-ZrO2 catalyst in the oxidation state of Ni becomes difficult to reduce, part of the NiO form exists, the number of active centers to reduce the three catalyst surface L acid center , Co-doped Ni / ZnO-ZrO2 catalyst surface weak acid center and moderate acid The strength and quantity of the center are increased, Mo doping weakens the strength of the center of weak acid and the center of the strong acid catalyst, but has little effect on the acidity.