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Deactivation mechanism of activated carbon supported copper oxide SCR catalysts in C 2 H 4 reductant
Author(s) -
Yang Li,
Jia Yuanyuan,
Cheng Jie,
Wu Xin,
He Jianlong,
Liu Fang
Publication year - 2019
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.23514
Subject(s) - catalysis , x ray photoelectron spectroscopy , activated carbon , inorganic chemistry , chemistry , copper , oxide , carbon black , temperature programmed reduction , bet theory , selective catalytic reduction , scanning electron microscope , materials science , chemical engineering , adsorption , organic chemistry , composite material , natural rubber , engineering
Current state‐of‐the‐art NH 3 ‐SCR technology based on vanadium catalysts suffers problems associated with NH 3 slip and poisoning of the catalyst and blockage of heat recovery steam generators (HRSG). If environmentally‐friendly catalysts capable of efficient operation at lower temperatures could be developed that used a reductant other than NH 3 , the issues with current state‐of‐the‐art SCR could be significantly lessened. Hence, in this study, activated carbon (AC) supported copper oxide‐based catalysts for SCR while using C 2 H 4 as a reductant was discussed. Reaction testing of catalysts demonstrated high initial NO conversion with steeply declining activity over 2 h of testing when C 2 H 4 was used as the reductant; in comparison, with the same catalyst and NH 3 as the reductant, stable, long‐term NO conversion was achieved, but at a lower rate than the initial reactivity with C 2 H 4 . As a consequence, catalyst characterization studies were performed to assess deactivation mechanisms when C 2 H 4 was the reductant. These studies included x‐ray diffraction, BET surface area and porosity, temperature programmed reduction, scanning electron microscopy, Raman spectroscopy and x‐ray photoelectron spectroscopy of both fresh and deactivated catalysts. The analytical results showed the surface area and porosity of the catalyst remained unchanged and the initially highly‐dispersed Cu species became agglomerated and more crystalline during reaction testing. Furthermore, carbon black was also detected on the catalyst surface after testing, presumably formed during the decomposition of C 2 H 4 . Both agglomeration of the active Cu species and blockage by carbon deposits would decrease the availability of active sites and lead to decreased catalytic activity.