Catalytic decomposition of gaseous PCDD/Fs over V2O5/TiO2-CNTs catalyst: Effect of NO and NH3 addition

• Catalytic decomposition of gaseous PCDD/Fs over V2O5/TiO2-CNTs composite catalysts.
• The removal efficiency of PCDD/Fs reaches 99.9% at 150 °C while adsorption is the main reason.
• NH3 restricts the adsorption of PCDD/Fs on catalyst, hence, reduces the removal efficiency.
• The positive effect of NO is due to the oxidation of NO to NO2 that speeds up the catalyst reoxidation.
• The activation energies for OCDD/F via catalysis are evidently reduced in the addition of NO and NH3.

There is a strong need for a control technology that simultaneously achieving the abatement of PCDD/Fs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) and nitrogen oxides (NOx) emissions in waste incineration industry. TiO2 and carbon nanotubes (CNTs) were used as composite carriers to support vanadium oxide as an innovative catalyst to simultaneously control PCDD/Fs and NO emissions. The removal efficiencies (RE) of PCDD/Fs by V2O5/TiO2-CNTs catalyst under a space velocity (SV) of 20,000 h−1 reaches 99.9% at 150 °C and adsorption is supposed to be the main mechanism at this temperature. The influence of NONH3 reaction on PCDD/Fs catalytic reaction is investigated. The kinetics analysis exhibits that the addition of NO and NH3 reduces the activation energies for OCDD (octachlorodibenzo-p-dioxin) and OCDF (octachlorodibenzofuran) decomposition to 3.6 kJ/mol and 5.4 kJ/mol respectively.

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