Assessment of metal sintering in the copper-zeolite hybrid catalyst for direct dimethyl ether synthesis using synchrotron-based X-ray absorption and diffraction

Andrei y Khodakov (1) , Vitaly Ordomsky (1) , Ana Palčić (2, 3) , Mengdie Cai (1) , Vijayanand Subramanian (1) , Yuan Luo (1) , Valentin Valtchev (2) , Simona Moldovan (4) , Ovidiu Ersen (4)

1 UCCS - Unité de Catalyse et Chimie du Solide - UMR 8181
2 LCS - Laboratoire catalyse et spectrochimie
3 Rudjer Boskovic Institute [Zagreb]
4 IPCMS - Institut de Physique et Chimie des Matériaux de Strasbourg

Dimethyl ether is one of the most promising environmentally optimized alternatives to the conventional fossil fuels and an important platform molecule for chemical industry. Catalyst deactivation is one of the most important challenges of the single-step dimethyl ether synthesis from syngas. Because of the lack of direct characterization techniques working under harsh reaction conditions, the information about deactivation mechanisms of bifunctional Cu/ZSM-5 catalysts is rather contradictory. In this paper, a combination of synchrotron-based in-situ time-resolved X-ray diffraction and X-ray absorption spectroscopy operating under high pressure and temperature alongside with the conventional ex-situ characterization uncovered very rapid copper sintering occurring under realistic conditions of direct dimethyl ether synthesis. Copper sintering was strongly affected by the presence of water either produced by the reaction or co-fed to the reactor. No copper oxidation was observed under a wide range of experimental conditions.

Keywords: zeolite; deactivation; hybrid catalyst; dimethyl ether; syngas; hydrogenation

Domains: Chemical Sciences

Andrei y Khodakov, Vitaly Ordomsky, Ana Palčić, Mengdie Cai, Vijayanand Subramanian, et al.. Assessment of metal sintering in the copper-zeolite hybrid catalyst for direct dimethyl ether synthesis using synchrotron-based X-ray absorption and diffraction. Catalysis Today, 2020, 343, pp.199-205. ⟨10.1016/j.cattod.2019.01.023⟩. ⟨hal-03035136⟩