An 18O2 Temperature-Programmed Isotope Exchange Study of Transition-Metal-Containing ZSM-5 Zeolites Used for Oxydehydrogenation of Ethane

Catalytic effect of transition metals on microwave-induced degradation of atrazine in mineral micropores

“…, Figure S2b) (Bulanek et al, 2004;Chen et al, 2000;Dubkov et al, 2002;Lazar et al, 1999;Voskoboinikov et al, 1998;Xia et al, 2010). It should be noted that the reactivity of oxygen coordinated to the FeO þ centers was so high that it could insert into the non-activated CeH bonds of hydrocarbons under ambient conditions, leading to selective formation of the hydroxylated products (Panov et al, 1998).…”

“…formation of dinuclear Cu þ and Fe 2þ complexes (Chen et al, 2000;Groothaert et al, 2005;Smeets et al, 2005;Voskoboinikov et al, 1998;Xia et al, 2010):…”

“…The chemical properties of zeolites, including density of acidic sites (determined by the framework Si/Al ratio), and the type and amount of metal ions and metal oxides doped in zeolite cages and channels are well known to affect their catalytic performance (Lone et al, 1984;Lukyanov, 1992;Pant, 2004, 2005). Zeolites modified with Cu 2þ and Fe 3þ have high catalytic activity for a range of oxidation reactions, such as oxidation of methane, propane, and benzene, and oxydehydrogenation of ethane (Chang et al, 1995;Nowinska et al, 2003;Ryder et al, 2003;Smeets et al, 2005 In addition, extra-framework metallic oxides may also be deposited in crystalline and/or amorphous forms on the internal and external surfaces of the zeolites (Gervasini, 1999 eOe) stabilized by the zeolite framework (Campa et al, 1994;Moretti, 1994;Moretti et al, 1999), while monomeric Cu 2þ has also been proposed to be the catalytic center (Larsen et al, 1994;Konduru and Chuang, 1999;Wichterlova et al, 1995). This study was conducted to harness the catalytic property of transition metals in redox reactions to develop effective mineral sorbents for microwave-induced degradation of atrazine.…”

Isotope Geochemistry of Zeolites

“…It should be pointed out that a vast literature exists on the behavior and characteristics of isotopes in synthetic zeolites and on isotopic studies related to industrial applications (see e.g. Chang et al 1995). This material is, however, outside the scope of this chapter and will only be mentioned when it has a direct bearing on the geochemistry of zeolites.…”

Nitrogen Chemistry and Coke Transformation of FCC Coked Catalyst during the Regeneration Process

“…Hydroxyl groups exist in the zeolitic component of the FCC catalyst 4 , hence, oxidation may occur between hydroxyl groups and absorbed aromatics or nitrogen-containing compounds. In isotopic exchange experiments, it is found that oxygen in ceria is mobile and can readily participate in oxidation reactions 30 31 , the zeolite alone makes a minor contribution to the available oxygen supply, unless it is modified by metal oxides 31 32 33 . It is further demonstrated that the combination of metal oxides and zeolite results in improved oxygen mobility within both components 31 32 .…”