Transition metal phosphide hydroprocessing catalysts: A review
Transition metal phosphide hydroprocessing catalysts: A review
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DOI：
10.1016/j.cattod.2008.09.019
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发表时间：
2009-05-15
期刊：
影响因子：
5.3
通讯作者：
Lee, Yong-Kul
中科院分区：
文献类型：
--
作者：
Oyama, S. Ted;Gott, Travis;Lee, Yong-Kul
油原料质量的降低以及限制运输燃料中硫含量的越来越严格的环境法规已经引起了对改进的加氢处理技术的需求。本文首先综述了近年来加氢脱硫（HDS）和加氢脱氮（HDN）催化剂和工艺的主要改进。然后，它描述了一类新的加氢处理催化剂，过渡金属磷化物，其已经作为一类有前途的高活性、稳定的催化剂出现。磷化物具有类似陶瓷的物理特性，因此坚固而坚硬，但保留了类似金属的电子和磁性。它们的晶体结构是基于三棱柱，但它们不像硫化物那样形成层状结构。它们在HDS和HDN中表现出优异的性能，其中最活性的磷化物Ni 2 P具有基于通过化学吸附滴定的位点（磷化物为CO，硫化物为O-2）超过促进的硫化物的活性。在4，6-二甲基二苯并噻吩等难处理的杂芳族化合物的HDS中，Ni 2 P通过氢化途径进行，而在取代的氮化合物如2-甲基哌啶的HDN中，它进行亲核取代。在Ni 2 P中用于加氢的活性位点具有四方锥形几何形状，而用于直接加氢脱硫的活性位点具有四面体几何形状。总体而言，Ni 2 P是一种有前途的催化剂，用于在氮和芳香族化合物存在下的深度加氢脱硫。(C)2008 Elsevier B. V.保留所有权利。
The diminishing quality of oil feedstocks coupled with increasingly more stringent environmental regulations limiting the content Of Sulfur in transportation fuels have given rise to a need for improved hydroprocessing technology. This review begins with a Summary of the major improvements in hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) catalysts and processes that have been reported in recent years. it then describes a new class of hydroprocessing catalysts, the transition metal phosphides, which have emerged as a promising group of high-activity, stable catalysts. The phosphides have physical properties resembling ceramics, so are strong and hard, yet retain electronic and magnetic properties similar to metals. Their crystal structures are based on trigonal prisms, yet they do not form layered structures like the sulfides. They display excellent performance in HDS and HDN, with the most active phosphide, Ni2P, having activity Surpassing that of promoted sulfides on the basis of sites titrated by chemisorption (CO for the phosphides, O-2 for the sulfides). In the HDS of difficult heteroaromatics like 4,6-dimethyidibenzothiophene Ni2P operates by the hydrogenation pathway, while in the HDN of substituted nitrogen compounds like 2-methylpiperidine it carries out nucleophilic substitution. The active sites for hydrogenation in Ni2P have a square pyramidal geometry, while those for direct hydrodesulfurization have a tetrahedral geometry. Overall, Ni2P is a promising catalyst for deep HDS in the presence of nitrogen and aromatic compounds. (C) 2008 Elsevier B.V. All rights reserved.