Abstract

Reducing the poisoning effect of alkaline earth metals over catalysts in industrial fields presents a great challenge to selective catalytic reduction (SCR) of NOx with ammonia. Herein, we successfully introduce sulfates to the surface of supported manganese-based oxides (Nb/MnO2-S) for trapping calcium species, and Nb/MnO2-S catalyst with superior low-temperature performance and calcium-resistant property still exhibits excellent de-NOx activity in a wide operating temperature window (175–350 °C, over 80 % NOx conversion with a gas hourly space velocity of 60,000 h−1) after calcium poisoning. In this case, the addition of sulfates increased the quantity of chemisorbed oxygen on Nb/MnO2-S, thus accelerating the redox cycle in NH3-SCR reaction. Significantly, compared with calcium-poisoned Nb/MnO2, relevant spectroscopy analysis and theoretical calculations further reveal that sulfates species prefer to interact with calcium and release the Nb active sites, which maintains the efficient NH3 adsorption and preserves a large amount of Brønsted acid sites over calcium-poisoned Nb/MnO2-S, thus promoting calcium-resistant performance. This work will provide a general strategy to develop calcium-resistant SCR catalysts with low-temperature activity for industrial applications.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.