Preparation of In,H-ZSM-5 for DeNOx reactions by solid-state ion exchange

Further insights on the physico-chemical aspects of PdIn-Hmordenite catalysts for the NOx-SCR with CH4

“…On the other hand, no reduction peak was detected at temperatures higher than 700°C, which indicates that there is no In 2 O 3 on the zeolitic surface. This is in agreement with the RSSIE process in which ion exchange starts already at about 400°C [7][8][9][17][18][19][20]25].…”

“…In this vein, Indium-exchanged catalysts prepared by both conventional ion exchange and solid state ion exchange have been studied by several research groups [16][17][18][19]. More efficient catalysts are obtained with the latter method because the formation of the active sites (InO) + is favored [20].…”

“…The solid state exchange can be performed under either hydrogen atmosphere at 500°C [16] or oxidative atmosphere between 500 and 700°C [17]. A recent publication has reported that In exchange proceeds under mild conditions and inert atmosphere [19]. The main motivation behind the preparation of those catalysts has been to obtain active systems for the SCR of NO x reaction.…”

Visualizing Element Migration over Bifunctional Metal‐Zeolite Catalysts and its Impact on Catalysis

“…[27] TheI n + ions could incorporate into the zeolitic component and neutralize the protonic sites of zeolites. [27,35] We found that the activity of In 2 O 3 /H-ZSM-5 in the MTH reaction was much lower than that of H-ZSM-5 (Table S4), in line with the loss of BASdensity driven by heat treatment (Figure 3c). Moreover,t he neutralization of BAS and loss of zeolite crystallinity was probably accelerated by the reductive atmosphere or formed water vapor in CO 2 hydrogenation, because only traces of BASs urvived after reaction (Figure 3b,c).…”

Catalytic Performance of In/HZSM‐5 for Coupling Propane with CO2 to Propylene

“…The redox property of the In/HZSM‐5 composite material can be confirmed by H 2 ‐TPR. As shown in Figure , there are three reduction characteristic peaks that appear in the reduction temperature ranges, which are ascribed to α, β and γ reduction peaks . Among them, β and γ peaks belongs to the high‐temperature reduction peak (300‐750 °C), which are produced by the reduction of the bulk phase of In 2 O 3 to In 0 .…”