The effect of the reduction temperature on the structure of Cu/ZnO/SiO2 catalysts for methanol synthesis

Autor:	J.C. van den Heuvel, E. Batyrev, W.P.A. Jansen, Hessel L. Castricum, J. Beckers
Přispěvatelé:	HIMS (FNWI)
Rok vydání:	2005
Předmět:	Chemistry Inorganic chemistry chemistry.chemical_element Heterogeneous catalysis Copper Catalysis Metal chemistry.chemical_compound Transition metal Chemisorption visual_art visual_art.visual_art_medium Crystallite Methanol Physical and Theoretical Chemistry
Zdroj:	Journal of Catalysis, 229(1), 136-143. Academic Press Inc.
ISSN:	0021-9517
Popis:	The structure of Cu/SiO 2 and Cu/ZnO/SiO 2 catalysts was studied after reduction at 450–1300 K. The influence of the ZnO promoter on the exposed Cu surface area and metal cluster size was determined by N 2 O chemisorption and X-ray diffraction. After reduction at 450 K, the metal surface area amounted to 9 m 2 /g cat for both catalysts. Oxygen uptake during N 2 O chemisorption increased significantly up to reduction temperatures of 800–900 K. This increase was most prominent for the ZnO-promoted catalyst, although no oxygen uptake was observed for a similarly treated ZnO/SiO 2 sample. The behaviour of the promoted catalyst can be explained by formation of Zn 0 , surface alloying, and segregation of ZnO x species on top of Cu clusters. The high thermostability of the catalysts was confirmed by in situ XRD measurements. The Cu crystallite size in both catalysts was about 4 nm, and did not increase when the reduction temperature was raised to 1100 K for 1 h.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::369cb25d3b65137bf3ca7a1da2c93df7 https://hdl.handle.net/11245/1.242867 Zobrazit plný text záznamu Full Text from ScienceDirect