Publication Date:
2018-03-14
Description:
Magnetic γ-Fe 2 O 3 catalysts were prepared by the microwave-assisted co-precipitation method utilizing direct-titrate and back-titrate precipitation technique with different precipitants ((NH 4 ) 2 CO 3 , NaOH, Na 2 CO 3 , and NH 4 OH), which were investigated in the selective catalytic reduction of NO x with NH 3 . The best γ-Fe 2 O 3 catalyst prepared method was direct-titration, using NH 4 OH as the precipitant, which exhibits a high de-NO x efficiency of above 90% at 325~400 °C. The direct-titration using NH 4 OH as the precipitant is effective to maintain the proper crystallization degree of γ-Fe 2 O 3 , improve the pore structure, and suppress the formation of α-Fe 2 O 3 phase, which are of benefits to get tiny and uniform discrete γ-Fe 2 O 3 particles with high activity in SCR. Meanwhile, NH 4 + -based precipitants in direct-titration leads to an increase of surface O/Fe atom ratio and more lattice oxygen sites are exposed to the crystal surface.
Print ISSN:
0930-7516
Electronic ISSN:
1521-4125
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
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