【摘要】 以多壁碳纳米管(CNT)为载体制备了负载型MoCo/CNT,并将其用于噻吩HDS反应.结果表明,在n(C4H4S)/n(H2)=2.3/97.7,GHSV=2200ml/(g·h),p=0.1MPa和T=623K的条件下,在7.2%(MoCo)/CNT催化剂上,噻吩HDS的比反应速率可达到0.64·10-3s-1,分别是9.7%(MoCo)/γAl2O3和16.9%(MoCo)/AC催化剂上的1.68和2.28倍.对比研究结果表明,用CNT代替γAl2O3或AC并不引起催化剂上噻吩HDS反应的表观活化能发生明显变化.与MoCo/γAl2O3或MoCo/AC催化剂相比,一方面,MoCo/CNT催化剂更易在较低温度下还原活化,并导致工作态催化剂表层活性Mo物种(Mo4+)在总Mo量中所占比例明显提高;另一方面,MoCo/CNT催化剂对H2具有更强的吸附和活化能力.这两个因素对提高催化剂活性都有重要贡献.更多还原

【Abstract】 Using home-made multiwalled carbon nanotubes （CNT） as support, Mo-Co/CNT was prepared by an incipient wetness technique. The catalytic performance of the catalyst for hydrodesulfurization （HDS） of thiophene was studied and compared with the reference systems of Mo-Co/γ-Al₂O₃ and Mo-Co/AC. Under the reaction conditions of n（C₄H₄S） / n（H₂） =2.3/97.7, GHSV= 2?200 ml/（g·h）, p=0.1 MPa and T=623 K, the specific reaction rate of thiophene HDS over 7.2%（Mo-Co）/CNT catalyst reached 0.64·10 -3 s -1 , which was 1.68 and 2.28 times as high as that over 9.7%（Mo-Co）/γ-Al₂O₃ and 16.9%（Mo-Co）/AC, respectively. Using the CNT in place of γ-Al₂O₃ or AC as the catalyst support caused little change in the apparent activation energy for thiophene HDS reaction, but led to a significant increase in concentration of active Mo species （Mo 4+ ） on the surface of the functioning catalyst. In addition, the catalyst Mo-Co/CNT could reversibly adsorb a greater amount of hydrogen under atmospheric pressure at temperatures from room temperature to 673 K. This unique feature would help to generate microenvironments with higher stationary-state concentration of active hydrogen-adspecies on the surface of the functioning catalyst. Both factors mentioned above were favorable to increase the rate of the thiophene HDS reaction.更多还原