TPR study and catalytic performance of noble metals modified Al2O3, TiO2 and ZrO2 for low-temperature NH3-SCO

Advanced Pd/CexZr(1−x)O2/MCM-41 catalysts for methane combustion: Effect of the zirconium and cerium loadings

“…This hypothesis could be strengthened by the absence of the PdH x decomposition peak on the Pd-CeZr10 and the Pd-CeZr20 profiles. In effect, according to the literature [20,[28][29][30], the strong interaction of Pd to the Ce-Zr oxides inhibits the formation of the PdH x species.…”

“…Furthermore, these results are in agreement with TEM observations, since the catalysts with the lower metal particle sizes (higher Ce and Zr loadings) have the higher reduction temperature. According to the literature, the decrease in particles diameter leads to an increase in metal-support interaction and then a drop of the PdO reducibility [17,30].…”

In situprobing of Pt/TiO2activity in low-temperature ammonia oxidation

“…[1][2][3][4] Supported platinum systems are utilized in diesel vehicles, among others, as a part of ammonia slip catalysts responsible for NH3 oxidation to molecular nitrogen. 5,6 Both model platinum systems -single-crystals, foils, and gauzes, [7][8][9][10][11][12] as well as supported platinum catalysts, [13][14][15][16][17][18][19][20] have been studied in detail as catalysts for the ammonia oxidation reaction, mostly within the Ostwald process for nitric acid production. DFT calculations [21][22][23][24][25] and kinetic modeling [26][27][28] were performed to gain more insight into the mechanism.…”

Progress on Noble Metal-Based Catalysts Dedicated to the Selective Catalytic Ammonia Oxidation into Nitrogen and Water Vapor (NH3-SCO)

“…Thus, a part of ammonia is oxidized over the noble metal-based catalyst to N 2 and NO x which is further transformed to N 2 over the SCR catalyst. Different arrangements of both metals were reported in the literature, i.e., noble/transition metal deposited on one support in systems such as (0.05 wt.%)Pt/(1 wt.%)Cu/Al 2 O 3 [48] [60] and Colombo et al [61]. E.g., Shrestha et al [57] pointed out the increase of N 2 selectivity (with a corresponding decrease in NO selectivity) with increasing copper loading of Cu/ZSM-5 (NH 3 -SCR layer), e.g., from 58% to 82% at 250 • C for 0.8 and 2.5 wt.% of Cu, respectively.…”