title: The Active Sites of a Rod-Shaped Hollandite DeNOx Catalyst.
abstract: The identification of catalytically active sites (CASs) in heterogeneous catalysis is of vital importance to design and develop improved catalysts, but remains a great challenge. The CASs have been identified in the low-temperature selective catalytic reduction of nitrogen oxides by ammonia (SCR) over a hollandite manganese oxide (HMO) catalyst with a rod-shaped morphology and one-dimensional tunnels. Electron microscopy and synchrotron X-ray diffraction determine the surface and crystal structures of the one-dimensional HMO rods closed by {100} side facets and {001} top facets. A combination of X-ray absorption spectra, molecular probes with potassium and nitric oxide, and catalytic tests reveals that the CASs are located on the {100} side facets of the HMO rods rather than on the top facets or in the tunnels, and hence semi-tunnel structural motifs on the {100} facets are evidenced to be the CASs of the SCR reaction. This work paves the way to further investigate the intrinsic mechanisms of SCR reactions.
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, 200433 Shanghai (P. R. China).
authors.forename: Pingping
authors.initials: P
authors.lastname: Hu
authors.affiliation: Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany).
authors.forename: Manfred Erwin
authors.initials: ME
authors.lastname: Schuster
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, 200433 Shanghai (P. R. China).
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, 200433 Shanghai (P. R. China).
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.affiliation: Research and Development Center for Functional Crystals, Institute of Physics, Chinese Academy of Sciences, 100190 Beijing (P. R. China).
authors.forename: Shifeng
authors.initials: S
authors.lastname: Jin
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, 200433 Shanghai (P. R. China).
authors.forename: Yaxin
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Fudan University, 220 Handan Road, 200433 Shanghai (P. R. China).
authors.forename: Weiming
authors.initials: W
authors.lastname: Hua
authors.affiliation: Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany).
authors.forename: Dang Sheng
authors.initials: DS
authors.lastname: Su
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, 200433 Shanghai (P. R. China). tangxf@fudan.edu.cn.
authors.forename: Xingfu
authors.initials: X
authors.lastname: Tang
keywords: DeNOx; active sites; heterogeneous catalysis; manganese oxides; structure elucidation