Influence of modifying additives on the catalytic activity and stability of Au/Fe2O3–MOx catalysts for the WGS reaction
Influence of modifying additives on the catalytic activity and stability of Au/Fe2O3–MOx catalysts for the WGS reaction
复制标题
DOI：
10.1007/s10562-005-5209-3
复制
发表时间：
2005-07
影响因子：
2.8
通讯作者：
J. Hua;Q. Zheng;Yuanhui Zheng;K. Wei;Xingyi Lin
中科院分区：
文献类型：
--
作者：
J. Hua;Q. Zheng;Yuanhui Zheng;K. Wei;Xingyi Lin
广泛研究了Au/ fe2o3 - mox催化剂（M = Zr、Mg、Ca、Ni、La、Cu、Zn、Al、Ba、Cr、Co、Ce、Mo、Bi、Ti、Mn）在水煤气转换反应中的活性和稳定性。zro2的加入显著提高了Au/ fe2o3的WGS活性和稳定性，MgO、CaO、NiO、La2O3、Cr2O3、CuO的加入对WGS活性和稳定性的影响较小。Bi、Ti和Mn氧化物严重降低了催化活性，而Zn、Al、Ba、Co、Ce和Mo氧化物的加入对催化活性和稳定性影响不明显。通过对部分制备样品和废样品的bet -表面积、孔隙结构、XRF、XRD和H2-TPR等表征，可以得出fe2o3 - mox复合氧化物负载的金催化剂的催化活性不仅取决于金颗粒的分散，还取决于复合氧化物载体的还原性能。由于改性金属氧化物的引入，不考虑含金量的波动以及比表面积和孔结构的变化。催化稳定性的提高可能是由于在催化操作过程中金颗粒的高分散性和fe3o4晶不易烧结的相对稳定所致。但也不能排除金属氧化物的改性加入对金催化剂催化性能的化学（电子）影响。
The activity and stability of Au/Fe2O3–MOxcatalysts (M = Zr, Mg, Ca, Ni, La, Cu, Zn, Al, Ba, Cr, Co, Ce, Mo, Bi, Ti, Mn) in water-gas shift reaction were investigated extensively. The WGS activity and stability of Au/Fe2O3is improved significantly upon addition of ZrO2and to a lesser extend MgO, CaO, NiO, La2O3, Cr2O3, CuO. In contrast, Bi, Ti and Mn oxides seriously decrease the catalytic activity while additions of Zn, Al, Ba, Co, Ce and Mo oxides do not influence evidently the catalytic activity and its stability. Based on the characterization using the methods of BET-surface area and pore structure XRF, XRD, and H2–TPR for some of as-prepared and spent samples, it could be concluded that the catalytic activity of gold catalysts supported on composite oxide of Fe2O3–MOxdepends not only on the dispersion of the gold particles but also on the reduction property of composite oxide supports, regardless of the fluctuation of gold loading and some change of specific surface area and pore structure due to introduction of the modifying metal oxides. The improvement of catalytic stability may be attributed to the comparative stabilization of high dispersion of gold particles and uneasily sintering of Fe3O4crystallites during the catalytic operation. However, the chemical (electronic) effects exerted by the modifying addition of metal oxides on the catalytic performance of gold catalyst may not be ruled out.