Facile synthesis of cost-effective iron enhanced hetero-structure activated carbon/geopolymer composite catalyst for NH3-SCR: Insight into the role of iron species

Cu/ZSM5-Geopolymer 3D-Printed Monoliths for the NH3-SCR of NOx

“…A remarkable effect of the introduction of copper on SCR performance was also reported in [20] for NH 4 Cu geopolymers. Similarly, it has been reported that the introduction of active iron in geopolymer/active carbon composites strongly improved SCR performance [21]. In agreement with Sazama et al [20], ammonia oxidation took place over the whole range of temperatures in addition to the SCR reaction, as shown by the larger NH 3 conversion compared to that of NO.…”

“…They are inherently macro/mesoporous materials with a high thermal stability and limited degradation of the structural network up to 800 • C [14]. GPs show good adsorption properties in many applications-typically water purification from organic molecules [15] or dissolved ions [16][17][18][19]-but they have been also investigated for SCR reactions both as NH 4 -and Cu-GP [20], and Fe-promoted in combination with activated carbon [21]. The possibility of varying their pore architecture in a wide range of values and the close similarity with zeolites concerning ion exchange, make GPs good candidates for the production of composite zeolite-GP materials [15].…”

Manganese‐enhanced porous phosphoric acid–based geopolymer templated by carbon for efficient NH3‐SCR of NOx

“…31,32 As shown in Figure 4B,D, all the samples possess predominant mesopores centered at ∼4 nm, which are beneficial for the SCR reaction. 33,34 In addition, the AC-regulated PAGs shows higher BET-specific surface areas and pore volumes than that of PAGs (Table 1), but the absolute increments are not obvious, which may be because the burning off of AC in PAG-AC mainly creates mechanical pores as discussed in microtopography section (Figure S4a). Moreover, it can be seen from Figure S5 that the geopolymer with higher water/binder ratio exhibits larger porosity, which should be the result of free water evaporation.…”

“…It can be seen from Figure 4A,C that all the samples exhibit type IV isotherms with a hysteresis loop at higher pressures, indicating the mesopore characteristics of the catalysts 31,32 . As shown in Figure 4B,D, all the samples possess predominant mesopores centered at ∼4 nm, which are beneficial for the SCR reaction 33,34 . In addition, the AC‐regulated PAGs shows higher BET‐specific surface areas and pore volumes than that of PAGs (Table 1), but the absolute increments are not obvious, which may be because the burning off of AC in PAG‐AC mainly creates mechanical pores as discussed in microtopography section (Figure S4a).…”

Promotion effect of Co addition on the activity and SO2 tolerance of CrCe catalysts for selective catalytic reduction of NOx with NH3 at middle–low temperatures

“…The band at 1240 cm −1 was related to monodentate nitrate. 40 The bands at 1201, 1291 and 1405 cm −1 were attributed to bridged nitrate, [41][42][43] and those at 1547 and 1578 cm −1 to bidentate nitrate. 44 When 5CoCrCe catalyst was exposed to NO + O 2 for 5 min, there was only one band at 1240 cm −1 (monodentate nitrate).…”