活性组元协同作用对加氢催化剂硫化行为的影响

Synergistic Effect of Active Components on the Sulfurization Behavior of Hydrogenation Catalysts

采用孔饱和浸渍法分别制备含活性金属Ni、Mo、W、Ni-Mo、Ni-W、Mo-W和Ni-Mo-W氧化态加氢催化剂,在相同硫化条件下对催化剂进行硫化。通过TPS、XPS、HRTEM、C-S方法对催化剂进行物化性质表征,并在加氢微反装置上考察催化剂对4,6-DMDBT加氢脱硫的反应活性,探究不同活性金属体系在硫化过程中硫化行为的规律。结果表明:金属Ni对W和较难硫化的Mo的硫化产生促进作用,形成的Ni-Mo(W)-S会促进Mo和W的硫化,降低其硫化温度;Mo元素的添加会促进Ni-W催化剂或单W催化剂中金属W的硫化,主金属Mo、W间会产生协同作用,有利于降低其硫化温度并形成条长更短且层数更多的活性相结构,因此三金属催化剂具有更高的加氢脱硫活性,Ni-Mo-W催化剂在320℃的加氢反应温度下可实现4,6-DMDBT的完全脱除。

The hydrogenation catalysts in the oxidation state containing the active metals Ni,Mo,W,Ni-Mo,Ni-W,Mo-W and Ni-Mo-W were prepared by pore saturation impregnation method,and were further sulfurized under the same sulfurization conditions.The physicochemical properties of the catalyst were characterized by TPS,XPS,HRTEM and C-S methods,and its catalytic activity for the hydrodesulfurization of 4,6-DMDBT was investigated on a hydrogenation micro-reactor,so as to explore the sulfurization behavior of different active metal components during the sulfurization process.The results indicate that Ni promotes the vulcanization of W and Mo,which are hard to be sulfurized,and the formed Ni-Mo(W)-S promotes the vulcanization of Mo and W and reduces the vulcanization temperature of active metals.Mo can promote the sulfidation of W in NiW or W catalyst.The synergistic effect will be produced between the active metal Mo and W,which is beneficial to reduce the vulcanization temperature and generate active phase structure with shorter strip length and more layers.Thus,the trimetallic catalyst has higher hydrodesulfurization activity,and Ni-Mo-W catalyst can completely remove 4,6-DMDBT at 320℃.