in-Situ FTIR Characterization of Reactions of CO with NO and NH3 over Pd-Based FCC Additives

Current use of FCC catalysts fail to eliminate the production of greenhouse gases, adding time and cost to the production of gasoline and other petroleum-based products. Using Pd as an additive can reduce the formation of both NO and CO species. FTIR has been used to characterize the reactions between CO and that of NO or NH₃ over a Pdⁿ⁺/Ceⁿ⁺/Na⁺/γ-Al2O3 catalyst at elevated temperatures. The presence of Pd increased the rate of reaction for formation of the different carboxylates/carbonates and nitriles/nitrates at both temperatures. When there is CO and either NO or NH₃ present, a formation of an isocyanate (NCO) species is observed. The NCO species is formed more rapidly in the presence of NO/CO when compared to NH₃/CO. The NCO species reacts when NO or O₂ is present, showing its importance as a reactant and not just a spectator species. Reaction pathways for the reduction of NO and CO have been proposed based on the interactions of the NCO species.