负载型铬基催化材料的制备与应用

摘要

Supporting chromium onto carriers (porous materials) not only can remarkably improve the dispersion of chromium active sites and retain their oxidation states,but also make supported chromium-based catalysts show the inherent advantages of the carrier materials in the pore structure,strong acidity and excellent performance of molecular diffusion. As a result,supported Cr-based catalysts usually exhibit relative higher catalytic activity and are effectively applied in various catalytic processes. In this paper,the recent progress in synthetic methods and main applications of supported Cr-based catalysts are reviewed. Meanwhile,the influences of synthetic methods,the properties of carriers,metal precursors and additives on the amount,the dispersion degree and the coordination state of chromium species,and thus the pore structure,the catalytic properties and lifetime of supported Cr-based catalysts are discussed in detailed. In addition,it can be seen that there is an important research prospect in the future for supported Cr-based catalysts in adjusting the pore structure and surface acidity of carriers and the interactions between carriers and chromium active species to enhance the dispersion and the stability of chromium species existed in the carriers.%负载型铬基催化材料不仅可显著提高铬活性组分的分散度并保留其多价态性，同时兼具多孔载体材料固有的孔结构、强酸性及优异的分子扩散性能，从而表现出良好的催化活性，并作为一类重要的催化剂有效应用于多种催化过程。本文详细阐述了目前负载型铬基催化剂在制备方法及催化应用方面的研究进展，并就合成方法、载体性质、金属前体及助剂等因素对铬物种引入量、分散程度及配位状态的影响以及进而造成对催化剂孔道结构、反应活性及使用寿命的影响进行了详尽地评述。同时指出了通过改变载体的表面酸性、孔结构及其与活性组分铬物种间的相互作用，从而提高铬物种在载体中的分散度和稳定性是今后负载型铬基催化材料研究的重要方向。