It has been reported that dimethyl ether (DME) can be more economically synthesized over multifunctional hybrid catalysts in a single step process [1,2]. Most studies on DME synthesis were carried out in a fixed-bed reactor in a large set of reaction conditions, in presence of dual catalyst systems consisting of a simple mixing between a methanol-synthesis phase (e.g., CuO-ZnO-Al2O3) and a methanol dehydration phase (?-Al2O3 or zeolites) [3]. Nevertheless, the full understanding of the mechanistic aspects behind the nature and behavior of the sites involved in the reaction process is not clarified, especially looking at the changing results obtained as a function of the COx/H2 feed atmosphere. In this work, we investigated the catalytic behavior of a previously optimized hybrid formulation, in which the active sites of a CuZnZr oxide phase and a homemade MFI-type zeolite were combined at nano-scale level during preparation, by assessing how the H2/COx mixture drives the direct formation of DME (see Fig. 1). Operando investigations and transient measures over the catalyst surface allowed to disclose the dynamics facilitating the activation of carbon oxides, as well as the topology and acidic property of the zeolite phase play a key role in the highly selective formation of DME.
INFLUENCE OF THE COX/H2 FEED ATMOSPHERE ON THE DIRECT SYNTHESIS OF DME IN PRESENCE OF HYBRID SYSTEMS
Serena Todaro;Catia Cannilla;Aldo Mezzapica;Francesco Frusteri;Giuseppe Bonura
2021
Abstract
It has been reported that dimethyl ether (DME) can be more economically synthesized over multifunctional hybrid catalysts in a single step process [1,2]. Most studies on DME synthesis were carried out in a fixed-bed reactor in a large set of reaction conditions, in presence of dual catalyst systems consisting of a simple mixing between a methanol-synthesis phase (e.g., CuO-ZnO-Al2O3) and a methanol dehydration phase (?-Al2O3 or zeolites) [3]. Nevertheless, the full understanding of the mechanistic aspects behind the nature and behavior of the sites involved in the reaction process is not clarified, especially looking at the changing results obtained as a function of the COx/H2 feed atmosphere. In this work, we investigated the catalytic behavior of a previously optimized hybrid formulation, in which the active sites of a CuZnZr oxide phase and a homemade MFI-type zeolite were combined at nano-scale level during preparation, by assessing how the H2/COx mixture drives the direct formation of DME (see Fig. 1). Operando investigations and transient measures over the catalyst surface allowed to disclose the dynamics facilitating the activation of carbon oxides, as well as the topology and acidic property of the zeolite phase play a key role in the highly selective formation of DME.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
