活性炭负载Pt-Ni双金属催化剂上十氢化萘脱氢

摘要

Pt-Ni bimetallic catalysts and the corresponding monometallic Pt catalysts supported on active carbon were prepared by incipient wetness impregnation and characterized by X-ray diffraction, N2 adsorption, and NH3-temperature programmed desorption. Their activities for decalin dehydro-genation were investigated at a superheated liquid film state in a batch reactor. The effects of tem-perature, impregnation sequence, and Pt/Ni molar ratio on the dehydrogenation activity and the naphthalene yield were investigated. The results show that the Pt-Ni bimetallic catalyst significantly enhanced hydrogen evolution compared with either Ni or Pt monometallic catalyst. The highest dehydrogenation conversion and naphthalene yield were obtained when the Pt/Ni molar ratio was 1:1 and Pt was impregnated first. The experimental results were correlated with density functional theory calculations of hydrogen binding energy (HBE) on different catalytic surfaces. The correla-tion confirmed that bimetallic surfaces with stronger HBEs had higher dehydrogenation activities.%采用等体积浸渍法制备了活性炭负载的具有脱氢活性的Pt-Ni双金属催化剂及相应的Pt单金属催化剂,并用X射线衍射、N2吸附-脱附和NH3-程序升温脱附对其进行了表征。在290°C下,研究了间歇反应条件下催化剂以过热液膜状态催化十氢化萘脱氢活性,考察了温度、浸渍顺序和Pt/Ni摩尔比对十氢化萘脱氢活性和萘产率的影响。结果表明,与单金属催化剂相比, Pt-Ni双金属催化剂上产氢效率显著提高。当Pt/Ni摩尔比为1：1, Pt首先浸渍时,得到的催化剂上脱氢转化率和萘产率最高。将实验结果与密度泛函理论计算的氢原子在不同催化表面的结合能关联证实,具有更强原子氢结合能的双金属表面具有更高的脱氢活性。