caa a22 4500 463253353 CHVBK 20180405153347.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1007/s10562-007-9176-8 doi (NATIONALLICENCE)springer-10.1007/s10562-007-9176-8 Isotopic Oxygen Exchange and EPR Studies of Superoxide Species on the SrF2/La2O3 Catalyst [Elektronische Daten] [Lihua Wang, Xiaodong Yi, Weizheng Weng, Chunxi Zhang, Xin Xu, Huilin Wan] By using the insitu IR spectroscopy, the superoxide species (O 2 − ), characterized by the O-O stretching peak at 1130cm−1, was detected on the SrF2/La2O3 catalyst at temperatures up to 973K. The introduction of 18O2 isotope caused the 1130cm−1 peak to shift to lower wavenumbers (1095 and 1064cm−1), consistent with the assignment of the spectra to the superoxide species. A good correlation between the rate of the disappearance of the O 2 − species and that of the formation of C2H4 was observed, suggesting that O 2 − was the active oxygen species responsible for the oxidative coupling of methane (OCM) on the SrF2/La2O3 catalyst. This conclusion was reinforced by the EPR experiments (gxx=2.0001, gyy=2.0045, gzz=2.0685), showing that O 2 − was the only paramagnetic oxygen species detectable on the O2-preadsorbed SrF2/La2O3 catalyst. These results suggest that superoxide O 2 − can be a stable active oxygen species, whose role in the OCM reaction cannot be overlooked. Springer Science+Business Media, LLC, 2007 Isotopic oxygen exchange nationallicence Insitu IR nationallicence EPR nationallicence Superoxide species nationallicence Methane oxidative coupling nationallicence Wang Lihua State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut Yi Xiaodong State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut Weng Weizheng State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut Zhang Chunxi Institute of Chemistry, Chinese Academy of Sciences, 100080, Beijing, P.R. China aut Xu Xin State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut Wan Huilin State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut Catalysis Letters Springer US; http://www.springer-ny.com 118/3-4(2007-10-01), 238-243 1011-372X 118:3-4<238 2007 118 10562 https://doi.org/10.1007/s10562-007-9176-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10562-007-9176-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wang Lihua State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut NATIONALLICENCE 700 1- Yi Xiaodong State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut NATIONALLICENCE 700 1- Weng Weizheng State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut NATIONALLICENCE 700 1- Zhang Chunxi Institute of Chemistry, Chinese Academy of Sciences, 100080, Beijing, P.R. China aut NATIONALLICENCE 700 1- Xu Xin State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut NATIONALLICENCE 700 1- Wan Huilin State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, P. R. China aut NATIONALLICENCE 773 0- Catalysis Letters Springer US; http://www.springer-ny.com 118/3-4(2007-10-01), 238-243 1011-372X 118:3-4<238 2007 118 10562 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer