Nielsen Ulla Gro, Topsøe Nan-Yu, Brorson Michael, Skibsted Jørgen, Jakobsen Hans J
Instrument Centre for Solid-State NMR Spectroscopy, Department of Chemistry, University of Aarhus, DK-8000 Aarhus C, Denmark.
J Am Chem Soc. 2004 Apr 21;126(15):4926-33. doi: 10.1021/ja030091a.
The first observations of the complete manifold of spinning sidebands (ssbs) including both the central and satellite transitions in (51)V MAS NMR spectra of surface vanadia nanoparticles on titania in DeNO(x) catalysts are presented. (51)V quadrupole coupling and chemical shift anisotropy parameters for the dominating vanadia structure are determined from (51)V MAS NMR spectra recorded at 9.4 and 14.1 T. Based on correlations previously established between (51)V NMR parameters and crystal structure data for inorganic vanadates, the NMR data are consistent with vanadium in a distorted octahedral oxygen coordination environment for the so-called strongly bonded vanadia species on the surface. The investigation includes two vanadia-titania model catalysts and six industrial-type DeNO(x) catalysts.
首次展示了在脱硝催化剂中二氧化钛负载的表面钒氧化物纳米颗粒的(51)V 魔角旋转核磁共振(MAS NMR)谱中,包括中心跃迁和卫星跃迁在内的完整旋转边带(ssbs)流形的观测结果。主导钒氧化物结构的(51)V 四极耦合和化学位移各向异性参数,是根据在 9.4 和 14.1 T 下记录的(51)V MAS NMR 谱确定的。基于先前在(51)V NMR 参数与无机钒酸盐晶体结构数据之间建立的相关性,NMR 数据与表面上所谓强键合钒氧化物物种的钒处于扭曲八面体氧配位环境一致。该研究包括两种钒氧化物 - 二氧化钛模型催化剂和六种工业型脱硝催化剂。