Ni-Mo双金属催化剂的甲烷化性能与耐硫稳定性

Catalytic activity and sulfur-resistance stability of Ni-Mo-based catalysts for syngas methanation

采用沉淀-浸渍法合成一系列Ni-Mo基双金属催化剂,在固定床反应器中对其催化活性和耐硫性能进行评价,并辅以不同的表征手段阐释其作用机理。实验结果表明,以MCM-41分子筛为载体的催化剂活性和稳定性优于以Na Y、γ-Al_2O_3和拟薄水铝石(PB)为载体的催化剂;反应前后催化剂的表征结果则说明Ni-Mo分子间适宜的相互作用是决定催化剂性能的关键。MCM-41载体催化剂中适宜的Ni-Mo分子间相互作用使得此催化剂中活性组分与载体间的相互作用适中,还原后的活性金属Ni能够均匀分散在载体表面,从而提高了催化剂的耐硫稳定性和抗积炭能力。不同Ni-Mo比同样会影响Ni-Mo分子间的相互作用,通过考察确定20Ni-10Mo/MCM-41的活性和稳定性最优。

A series of Ni-Mo-based catalysts, prepared by precipitation-impregnation method, were studied for catalytic activity and sulfur resistance in a fixed bed reactor. Different characterization techniques were carried out to interpret their reaction mechanisms. Compared to catalysts with supports of Na Y, γ-Al2O3 and pseudoboehmite（PB）, catalyst with MCM-41 support showed superior activity and stability. Characterization on catalysts before and after reaction showed that Ni-Mo interaction plays critical role in catalyst performance. In the catalyst supported with MCM-41, Ni-Mo interaction resulted in appropriate interaction between active species and support. Reduced active Ni was homogeneously dispersed on support surface, which enhanced sulfur-resistance stability and anticarbon deposition. Different Ni/Mo ratios also affected Ni-Mo interaction in catalysts. It was found that the 20 Ni-10 Mo/MCM-41 catalysts exhibited the best performance.