负载型Pt-Ni双金属催化剂上甘油氢解反应性能

摘要

甘油氢解转化是获得高附加值化学品的主要途径之一。通过浸渍法制备了γ-Al2O3负载Pt-Ni双金属的甘油氢解催化剂。采用X射线衍射（XRD）、氮气物理吸附、透射电子显微镜（TEM）、程序升温还原（TPR）以及X射线能谱分析（XPS）等手段对催化剂进行了表征。结果表明：在γ-Al2O3负载的Pt-Ni双金属催化剂中，Pt原子与Ni原子之间发生了相互作用并形成了PtNi合金簇，使得Pt-Ni双金属催化剂产生了协同作用，对乙二醇的选择性大大高于 Pt/γ-Al2O3和 Ni/γ-Al2O3等单金属组分催化剂。固定床反应器实验结果表明，在473 K和3.0 MPa氢气压力下，负载量为2%Pt-15%Ni/γ-Al2O3催化剂对乙二醇的选择性最高，达到28.4%，此时甘油的转化率为94.8%，1,2-丙二醇的选择性为58.2%。%Glycerol hydrogenolysis is one of the important ways to obtain high value-added chemicals from biomass derivatives. Bimetallic platinum-nickel catalysts supported onγ-Al2O3 were prepared by co-impregnation, and characterized by using powder X-ray diffraction (XRD), N2 physical adsorption, transmission electron microscopy (TEM), temperature-programmed reduction (TPR) and X-ray photoelectron spectra (XPS). The metal-metal interaction and the formation of PtNi alloy cluster in the bimetallic Pt-Ni catalyst produced synergistic effect and exhibited a much higher selectivity toward ethylene glycol than monometallic catalysts Pt/γ-Al2O3 and Ni/γ-Al2O3. The bimetallic catalyst with a loading of 2%Pt and 15%Ni showed the highest selectivity toward ethylene glycol, which was 28.4%, with a glycerol conversion of 94.8% conversion and a selectivity of 58.2% to 1,2-PDO.