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Indexed by:期刊论文

Date of Publication:2013-01-17

Journal:APPLIED CATALYSIS B-ENVIRONMENTAL

Included Journals:SCIE、EI

Volume:129

Page Number:491-500

ISSN No.:0926-3373

Key Words:Co3O4 nanorods; NOx reduction; Catalyst morphology; Catalytic activity

Abstract:In this work, single-crystalline one-dimensional Co3O4 nanorods with well-defined crystal planes as catalysts in the selective catalytic reduction of NO by ammonia are investigated. The Co3O4 nanorods synthesized by ethylene glycol-mediated precipitation at 160 degrees C predominantly expose {1 1 0} planes which are rich in Co3+ species, while the traditional Co3O4 nanoparticles expose the {0 0 1} and {1 1 1} planes which contain mainly Co2+ species. Compared with Co3O4 nanoparticles, Co3O4 nanorods show much higher NOx conversion in NH3-SCR reaction. TPD of various reactant gases, including NH3, NO, NO/NH3, NO/O-2, NO/NH3/O-2, and transient experiment reveals Co3O4 nanorods adsorb a large amount of ammonia on their surface. Slight surface H-2 reduction significantly decreases the activity of Co3O4 nanocrystals, while O-2 re-oxidation partially recovers their catalytic activity, demonstrating the presence of Co3+ cations on the surface of Co3O4 nanocatalysts actually acts as the active sites in NH3-SCR reaction. The present results indicate that novel catalyst with high activity can be designed by morphology control at nanoscale. (c) 2012 Elsevier B.V. All rights reserved.