离子交换程序对Pd/Y催化剂萘加氢活性和耐硫性能的影响

运用程序升温还原、氢的化学吸附和NH3的程序升温脱附方法研究了离子交换程序对Pd/Y催化剂萘加氢活性和耐硫性能的影响。实验结果表明,采用不同离子交换程序制备的催化剂,Pd的分散程度以及催化剂表面的酸量存在显著差别(H与Pd摩尔比介于0.44～1.34之间,酸量介于123～938μmol/g之间),从而影响催化剂的萘加氢活性和抗硫性能。以动力学分析为依据,考察了在反应体系中加入300μg/g噻吩对萘加氢反应的影响。噻吩的加入改变了萘加氢连串反应各步骤的相对反应速率,噻吩对Pd/Y催化剂催化四氢萘加氢生成十氢萘的抑制作用比对催化萘加氢生成四氢萘的抑制作用更为显著。

Effect of Ion Exchange Procedure on Activity and Sulfur Tolerance of Pd/Y Catalysts for Naphthalene Hydrogenation

Effect of ion exchange procedure on performance of Pd/Y catalysts for naphthalene hydrogenation with or without presence of thiophene was studied by means of temperature programmed reduction(TPR),H_2 chemisorption and temperature programmed desorption of ammonia.Changes of ion-exchange procedures caused differences in palladium dispersion and catalyst acidity,i.e.the n(H)∶n(Pd)varied from 0.44 to 1.34 and acidity varied from 123 μmol/g to 938 μmol/g.Poisoning effect of thiophene on consecutive hydrogenation of naphthalene was investigated on basis of kinetics.Rate constant ratio of two consecutive steps varied obviously after addition of 300 μg/g thiophene into the reaction system.Inhibitory effect of thiophene on tetralin hydrogenation was much more prominent than that on naphthalene hydrogenation.