Travert A, Dujardin C, Maugé F, Veilly E, Cristol S, Paul J-F, Payen E
Laboratoire Catalyse et Spectrochimie, UMR CNRS 6506, ENSICAEN, Université de Caen, 14050 Caen Cedex, France.
J Phys Chem B. 2006 Jan 26;110(3):1261-70. doi: 10.1021/jp0536549.
Experimental IR spectra of carbon monoxide adsorbed on a series of Mo/Al2O3, CoMo/Al2O3, and NiMo/Al2O3 sulfided catalysts have been compared to ab initio DFT calculations of CO adsorption on CoMo and NiMo model surfaces. This approach allows the main IR features of CO adsorbed on the sulfide phase to be assigned with an uncertainty of 15 cm(-1). On the CoMo system, the band at 2070 cm(-1) is specific of the promotion by Co and is assigned to CO interacting either with a Co atom or with a Mo atom adjacent to a Co atom. On the NiMo system, CO adsorption on Ni centers of the promoted phase leads to a high-wavenumber band at approximately 2120 cm(-1) that strongly overlaps the band at 2110 cm(-1) characteristic of nonpromoted Mo sites. For NiMo and CoMo catalysts, broad shoulders at low wave numbers (below 2060 cm(-1)) are characteristic of Mo centers adjacent to promoter atoms, indicating a partial decoration of the MoS2 edges by the promoter.
已将吸附在一系列硫化的Mo/Al₂O₃、CoMo/Al₂O₃和NiMo/Al₂O₃催化剂上的一氧化碳的实验红外光谱与一氧化碳在CoMo和NiMo模型表面吸附的从头算密度泛函理论（DFT）计算结果进行了比较。这种方法能够将吸附在硫化相上的一氧化碳的主要红外特征进行归属，其不确定度为15 cm⁻¹。在CoMo体系中，2070 cm⁻¹处的谱带是Co促进作用所特有的，可归属为与Co原子或与相邻Co原子的Mo原子相互作用的一氧化碳。在NiMo体系中，在促进相的Ni中心上吸附一氧化碳会导致在约2120 cm⁻¹处出现一个高波数谱带，该谱带与未促进的Mo位点特征性的2110 cm⁻¹处的谱带强烈重叠。对于NiMo和CoMo催化剂，低波数（低于2060 cm⁻¹）处的宽肩峰是与促进剂原子相邻的Mo中心的特征，表明MoS₂边缘被促进剂部分修饰。
