Amorphous chromia for low-temperature selective catalytic reduction of nitric oxide

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Industrial and Engineering Chemistry Research; (United States)

DOI:https://doi.org/10.1021/ie00106a001· OSTI ID:5536194

Curry-Hyde, E; Baiker, A ^[1]

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1. Dept. of Industrial and Engineering Chemistry, Swiss Federal Inst. of Technology, ETH-Zentrum, CH-8092 Zuerich (CH)

This paper reports on high surface area amorphous chromia found to be a highly active and selective catalyst for the reduction of nitric oxide by ammonia in an oxygen excess. A comparison to a V{sub 2}O{sub 5}/TiO{sub 2} catalyst shows that at a space velocity of 24000 h{sup {minus}1} in 900 ppm NO, 900 ppm NH{sub 3}, and 1.8% O{sub 2}, over 90% conversion occurs at 140{degrees}C on the amorphous chromia whereas over 230{degrees}C is required to reach the same conversion over the V{sub 2}O{sub 5}/TiO{sub 2} catalyst. Both catalysts showed the same high selectivity to N{sub 2} formation and low NH{sub 3} oxidation tendencies. Long-term testing with the chromia catalyst showed a slight deactivation initially. The catalyst achieved steady state after 120 h on stream. No change in selectivity was observed in this period. X-ray diffraction measurements of the chromia before and after the long-term test indicate that the amorphous bulk structure was maintained. The mean apparent activation energies for NO reduction over the amorphous chromia were 50 and 62 kJ/mol over the V{sub 2}O{sub 5}/TiO{sub 2} catalyst.

• OSTI ID: 5536194
• Journal Information: Industrial and Engineering Chemistry Research; (United States), Journal Name: Industrial and Engineering Chemistry Research; (United States) Vol. 29:10; ISSN IECRE; ISSN 0888-5885
• Country of Publication: United States
• Language: English

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Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ACTIVATION ENERGY
AIR POLLUTION CONTROL
AMORPHOUS STATE
CATALYSTS
CATALYTIC CONVERTERS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
COHERENT SCATTERING
CONTROL
DENITRIFICATION
DIFFRACTION
ENERGY
EQUIPMENT
FLUE GAS
GASEOUS WASTES
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
REDUCTION
SCATTERING
SELECTIVE CATALYTIC REDUCTION
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
TRANSITION ELEMENT COMPOUNDS
WASTES
X-RAY DIFFRACTION